table
elementcaption
element,
followed by zero or more colgroup
elements, followed
optionally by a thead
element, followed optionally by
a tfoot
element, followed by either zero or more
tbody
elements or one or more tr
elements, followed optionally by a tfoot
element (but
there can only be one tfoot
element child in
total), optionally intermixed with one or more script-supporting elements.border
sortable
interface HTMLTableElement : HTMLElement { attribute HTMLTableCaptionElement? caption; HTMLElement createCaption(); void deleteCaption(); attribute HTMLTableSectionElement? tHead; HTMLElement createTHead(); void deleteTHead(); attribute HTMLTableSectionElement? tFoot; HTMLElement createTFoot(); void deleteTFoot(); readonly attribute HTMLCollection tBodies; HTMLElement createTBody(); readonly attribute HTMLCollection rows; HTMLElement insertRow(optional long index = -1); void deleteRow(long index); attribute DOMString border; attribute boolean sortable; void stopSorting(); };
The table
element represents data with
more than one dimension, in the form of a table.
The table
element takes part in
the table model. Tables have rows, columns, and
cells given by their descendants. The rows and columns form a grid;
a table's cells must completely cover that grid without overlap.
Precise rules for determining whether this conformance requirement is met are described in the description of the table model.
Authors are encouraged to provide information describing how to interpret complex tables. Guidance on how to provide such information is given below.
If a table
element has a (non-conforming) summary
attribute, and the user
agent has not classified the table as a layout table, the user agent
may report the contents of that attribute to the user.
Tables should not be used as layout aids. Historically, many Web authors have tables in HTML as a way to control their page layout making it difficult to extract tabular data from such documents. In particular, users of accessibility tools, like screen readers, are likely to find it very difficult to navigate pages with tables used for layout. If a table is to be used for layout it must be marked with the attribute role="presentation" for a user agent to properly represent the table to an assistive technology and to properly convey the intent of the author to tools that wish to extract tabular data from the document.
There are a variety of alternatives to using HTML tables for layout, primarily using CSS positioning and the CSS table model. [CSS]
The border
attribute may be specified on a table
element to
explicitly indicate that the table
element is not being
used for layout purposes. If specified, the attribute's value must
either be the empty string or the value "1
".
The attribute is used by certain user agents as an indication that
borders should be drawn around cells of the table.
Tables can be complicated to understand and navigate. To help users with this, user agents should clearly delineate cells in a table from each other, unless the user agent has classified the table as a layout table.
Authors and implementors are encouraged to consider using some of the table design techniques described below to make tables easier to navigate for users.
User agents, especially those that do table analysis on arbitrary content, are encouraged to find heuristics to determine which tables actually contain data and which are merely being used for layout. This specification does not define a precise heuristic, but the following are suggested as possible indicators:
Feature | Indication |
---|---|
The use of the role attribute with the value presentation
| Probably a layout table |
The use of the border attribute with the non-conforming value 0
| Probably a layout table |
The use of the non-conforming cellspacing and cellpadding attributes with the value 0
| Probably a layout table |
The use of caption , thead , or th elements
| Probably a non-layout table |
The use of the headers and scope attributes
| Probably a non-layout table |
The use of the border attribute with a value other than 0
| Probably a non-layout table |
Explicit visible borders set using CSS | Probably a non-layout table |
The use of the summary attribute
| Not a good indicator (both layout and non-layout tables have historically been given this attribute) |
It is quite possible that the above suggestions are wrong. Implementors are urged to provide feedback elaborating on their experiences with trying to create a layout table detection heuristic.
The sortable
attribute is used in the table
sorting model.
caption
[ = value ]Returns the table's caption
element.
Can be set, to replace the caption
element. If the
new value is not a caption
element, throws a
HierarchyRequestError
exception.
createCaption
()Ensures the table has a caption
element, and returns it.
deleteCaption
()Ensures the table does not have a caption
element.
tHead
[ = value ]Returns the table's thead
element.
Can be set, to replace the thead
element. If the
new value is not a thead
element, throws a
HierarchyRequestError
exception.
createTHead
()Ensures the table has a thead
element, and returns it.
deleteTHead
()Ensures the table does not have a thead
element.
tFoot
[ = value ]Returns the table's tfoot
element.
Can be set, to replace the tfoot
element. If the
new value is not a tfoot
element, throws a
HierarchyRequestError
exception.
createTFoot
()Ensures the table has a tfoot
element, and returns it.
deleteTFoot
()Ensures the table does not have a tfoot
element.
tBodies
Returns an HTMLCollection
of the tbody
elements of the table.
createTBody
()Creates a tbody
element, inserts it into the table, and returns it.
rows
Returns an HTMLCollection
of the tr
elements of the table.
insertRow
( [ index ] )Creates a tr
element, along with a tbody
if required, inserts them into the table at the position given by the argument, and returns the tr
.
The position is relative to the rows in the table. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the table.
If the given position is less than −1 or greater than the number of rows, throws an IndexSizeError
exception.
deleteRow
(index)Removes the tr
element with the given position in the table.
The position is relative to the rows in the table. The index −1 is equivalent to deleting the last row of the table.
If the given position is less than −1 or greater than the index of the last row, or if there are no rows, throws an IndexSizeError
exception.
The caption
IDL
attribute must return, on getting, the first caption
element child of the table
element, if any, or null
otherwise. On setting, if the new value is a caption
element, the first caption
element child of the
table
element, if any, must be removed, and the new
value must be inserted as the first node of the table
element. If the new value is not a caption
element,
then a HierarchyRequestError
DOM exception must be
thrown instead.
The createCaption()
method must return the first caption
element child of
the table
element, if any; otherwise a new
caption
element must be created, inserted as the first
node of the table
element, and then returned.
The deleteCaption()
method must remove the first caption
element child of
the table
element, if any.
The tHead
IDL
attribute must return, on getting, the first thead
element child of the table
element, if any, or null
otherwise. On setting, if the new value is a thead
element, the first thead
element child of the
table
element, if any, must be removed, and the new
value must be inserted immediately before the first element in the
table
element that is neither a caption
element nor a colgroup
element, if any, or at the end
of the table if there are no such elements. If the new value is not
a thead
element, then a
HierarchyRequestError
DOM exception must be thrown
instead.
The createTHead()
method must return the first thead
element child of the
table
element, if any; otherwise a new
thead
element must be created and inserted immediately
before the first element in the table
element that is
neither a caption
element nor a colgroup
element, if any, or at the end of the table if there are no such
elements, and then that new element must be returned.
The deleteTHead()
method must remove the first thead
element child of the
table
element, if any.
The tFoot
IDL
attribute must return, on getting, the first tfoot
element child of the table
element, if any, or null
otherwise. On setting, if the new value is a tfoot
element, the first tfoot
element child of the
table
element, if any, must be removed, and the new
value must be inserted immediately before the first element in the
table
element that is neither a caption
element, a colgroup
element, nor a thead
element, if any, or at the end of the table if there are no such
elements. If the new value is not a tfoot
element, then
a HierarchyRequestError
DOM exception must be thrown
instead.
The createTFoot()
method must return the first tfoot
element child of the
table
element, if any; otherwise a new
tfoot
element must be created and inserted immediately
before the first element in the table
element that is
neither a caption
element, a colgroup
element, nor a thead
element, if any, or at the end of
the table if there are no such elements, and then that new element
must be returned.
The deleteTFoot()
method must remove the first tfoot
element child of the
table
element, if any.
The tBodies
attribute must return an HTMLCollection
rooted at the
table
node, whose filter matches only
tbody
elements that are children of the
table
element.
The createTBody()
method must create a new tbody
element, insert it
immediately after the last tbody
element child in the
table
element, if any, or at the end of the
table
element if the table
element has no
tbody
element children, and then must return the new
tbody
element.
The rows
attribute
must return an HTMLCollection
rooted at the
table
node, whose filter matches only tr
elements that are either children of the table
element,
or children of thead
, tbody
, or
tfoot
elements that are themselves children of the
table
element. The elements in the collection must be
ordered such that those elements whose parent is a
thead
are included first, in tree order, followed by
those elements whose parent is either a table
or
tbody
element, again in tree order, followed finally by
those elements whose parent is a tfoot
element, still
in tree order.
The behavior of the insertRow(index)
method depends on the state of
the table. When it is called, the method must act as required by the
first item in the following list of conditions that describes the
state of the table and the index argument:
rows
collection:IndexSizeError
exception.rows
collection has
zero elements in it, and the table
has no
tbody
elements in it:tbody
element, then
create a tr
element, then append the tr
element to the tbody
element, then append the
tbody
element to the table
element, and
finally return the tr
element.rows
collection has
zero elements in it:tr
element, append it to
the last tbody
element in the table, and return the
tr
element.rows
collection:tr
element, and append it
to the parent of the last tr
element in the rows
collection. Then, the newly
created tr
element must be returned.tr
element, insert it
immediately before the indexth tr
element in the rows
collection,
in the same parent, and finally must return the newly created
tr
element.When the deleteRow(index)
method is called, the user agent
must run the following steps:
If index is equal to −1, then
index must be set to the number of items in the
rows
collection, minus
one.
Now, if index is less than zero, or
greater than or equal to the number of elements in the rows
collection, the method must
instead throw an IndexSizeError
exception, and these
steps must be aborted.
Otherwise, the method must remove the indexth element in the rows
collection from its parent.
The border
IDL
attribute must reflect the content attribute of the
same name.
The stopSorting()
method is used in the table
sorting model.
The IDL attribute sortable
must
reflect the sortable
content attribute.
Here is an example of a table being used to mark up a Sudoku puzzle. Observe the lack of headers, which are not necessary in such a table.
<section> <style scoped> table { border-collapse: collapse; border: solid thick; } colgroup, tbody { border: solid medium; } td { border: solid thin; height: 1.4em; width: 1.4em; text-align: center; padding: 0; } </style> <h1>Today's Sudoku</h1> <table> <colgroup><col><col><col> <colgroup><col><col><col> <colgroup><col><col><col> <tbody> <tr> <td> 1 <td> <td> 3 <td> 6 <td> <td> 4 <td> 7 <td> <td> 9 <tr> <td> <td> 2 <td> <td> <td> 9 <td> <td> <td> 1 <td> <tr> <td> 7 <td> <td> <td> <td> <td> <td> <td> <td> 6 <tbody> <tr> <td> 2 <td> <td> 4 <td> <td> 3 <td> <td> 9 <td> <td> 8 <tr> <td> <td> <td> <td> <td> <td> <td> <td> <td> <tr> <td> 5 <td> <td> <td> 9 <td> <td> 7 <td> <td> <td> 1 <tbody> <tr> <td> 6 <td> <td> <td> <td> 5 <td> <td> <td> <td> 2 <tr> <td> <td> <td> <td> <td> 7 <td> <td> <td> <td> <tr> <td> 9 <td> <td> <td> 8 <td> <td> 2 <td> <td> <td> 5 </table> </section>
For tables that consist of more than just a grid of cells with headers in the first row and headers in the first column, and for any table in general where the reader might have difficulty understanding the content, authors should include explanatory information introducing the table. This information is useful for all users, but is especially useful for users who cannot see the table, e.g. users of screen readers.
Such explanatory information should introduce the purpose of the table, outline its basic cell structure, highlight any trends or patterns, and generally teach the user how to use the table.
For instance, the following table:
Negative | Characteristic | Positive |
---|---|---|
Sad | Mood | Happy |
Failing | Grade | Passing |
...might benefit from a description explaining the way the table is laid out, something like "Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column".
There are a variety of ways to include this information, such as:
<p id="summary">In the following table, characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> <table aria-describedby="summary"> <caption>Characteristics with positive and negative sides</caption> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table>
In the example above the
aria-describedby
attribute is used to explicitly associate the information
with the table for assistive technology users.
caption
<table> <caption> <strong>Characteristics with positive and negative sides.</strong> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> </caption> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table>
caption
, in a details
element<table> <caption> <strong>Characteristics with positive and negative sides.</strong> <details> <summary>Help</summary> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> </details> </caption> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table>
figure
<figure> <figcaption>Characteristics with positive and negative sides</figcaption> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> <table> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table> </figure>
figure
's figcaption
<figure> <figcaption> <strong>Characteristics with positive and negative sides</strong> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> </figcaption> <table> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table> </figure>
Authors may also use other techniques, or combinations of the above techniques, as appropriate.
The best option, of course, rather than writing a description explaining the way the table is laid out, is to adjust the table such that no explanation is needed.
In the case of the table used in the examples above, a simple
rearrangement of the table so that the headers are on the top and
left sides removes the need for an explanation as well as removing
the need for the use of headers
attributes:
<table> <caption>Characteristics with positive and negative sides</caption> <thead> <tr> <th> Characteristic <th> Negative <th> Positive <tbody> <tr> <th> Mood <td> Sad <td> Happy <tr> <th> Grade <td> Failing <td> Passing </table>
Good table design is key to making tables more readable and usable.
In visual media, providing column and row borders and alternating row backgrounds can be very effective to make complicated tables more readable.
For tables with large volumes of numeric content, using monospaced fonts can help users see patterns, especially in situations where a user agent does not render the borders. (Unfortunately, for historical reasons, not rendering borders on tables is a common default.)
In speech media, table cells can be distinguished by reporting the corresponding headers before reading the cell's contents, and by allowing users to navigate the table in a grid fashion, rather than serializing the entire contents of the table in source order.
Authors are encouraged to use CSS to achieve these effects.
User agents are encouraged to render tables using these techniques whenever the page does not use CSS and the table is not classified as a layout table.
caption
elementtable
element.table
elements.interface HTMLTableCaptionElement : HTMLElement {};
The caption
element represents the title of the table
that is its parent, if it has a parent and that is a table
element.
The caption
element takes part in the table model.
When a table
element is the only content in a figure
element other
than the figcaption
, the caption
element should be omitted in favor of
the figcaption
.
A caption can introduce context for a table, making it significantly easier to understand.
Consider, for instance, the following table:
1 | 2 | 3 | 4 | 5 | 6 | |
---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 | 7 |
2 | 3 | 4 | 5 | 6 | 7 | 8 |
3 | 4 | 5 | 6 | 7 | 8 | 9 |
4 | 5 | 6 | 7 | 8 | 9 | 10 |
5 | 6 | 7 | 8 | 9 | 10 | 11 |
6 | 7 | 8 | 9 | 10 | 11 | 12 |
In the abstract, this table is not clear. However, with a caption giving the table's number (for reference in the main prose) and explaining its use, it makes more sense:
<caption> <p>Table 1. <p>This table shows the total score obtained from rolling two six-sided dice. The first row represents the value of the first die, the first column the value of the second die. The total is given in the cell that corresponds to the values of the two dice. </caption>
This provides the user with more context:
1 | 2 | 3 | 4 | 5 | 6 | |
---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 | 7 |
2 | 3 | 4 | 5 | 6 | 7 | 8 |
3 | 4 | 5 | 6 | 7 | 8 | 9 |
4 | 5 | 6 | 7 | 8 | 9 | 10 |
5 | 6 | 7 | 8 | 9 | 10 | 11 |
6 | 7 | 8 | 9 | 10 | 11 | 12 |
colgroup
elementtable
element, after any
caption
elements and before any thead
,
tbody
, tfoot
, and tr
elements.span
attribute is present: Empty.span
attribute is absent: Zero or more col
and template
elements.span
interface HTMLTableColElement : HTMLElement { attribute unsigned long span; };
The colgroup
element represents a group of one or more columns in the table
that
is its parent, if it has a parent and that is a table
element.
If the colgroup
element contains no col
elements, then the element may have a span
content attribute
specified, whose value must be a valid non-negative
integer greater than zero.
The colgroup
element and its span
attribute take part in the
table model.
The span
IDL
attribute must reflect the content attribute of the
same name. The value must be limited to only non-negative
numbers greater than zero.
col
elementcolgroup
element that doesn't have
a span
attribute.span
HTMLTableColElement
, same as for
colgroup
elements. This interface defines one member,
span
.
If a col
element has a parent and that is a
colgroup
element that itself has a parent that is a
table
element, then the col
element
represents one or more columns in the column group represented by that
colgroup
.
The element may have a span
content attribute
specified, whose value must be a valid non-negative
integer greater than zero.
The col
element and its span
attribute take part in the
table model.
The span
IDL
attribute must reflect the content attribute of the
same name. The value must be limited to only non-negative
numbers greater than zero.
tbody
elementtable
element, after any
caption
, colgroup
, and
thead
elements, but only if there are no
tr
elements that are children of the
table
element.tr
and script-supporting elementsinterface HTMLTableSectionElement : HTMLElement { readonly attribute HTMLCollection rows; HTMLElement insertRow(optional long index = -1); void deleteRow(long index); };
The HTMLTableSectionElement
interface is also
used for thead
and tfoot
elements.
The tbody
element represents a block of rows that consist of a body of data for
the parent table
element, if the tbody
element has a parent and it is a table
.
The tbody
element takes part in the table
model.
rows
Returns an HTMLCollection
of the tr
elements of the table section.
insertRow
( [ index ] )Creates a tr
element, inserts it into the table section at the position given by the argument, and returns the tr
.
The position is relative to the rows in the table section. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the table section.
If the given position is less than −1 or greater than the number of rows, throws an IndexSizeError
exception.
deleteRow
(index)Removes the tr
element with the given position in the table section.
The position is relative to the rows in the table section. The index −1 is equivalent to deleting the last row of the table section.
If the given position is less than −1 or greater than the index of the last row, or if there are no rows, throws an IndexSizeError
exception.
The rows
attribute
must return an HTMLCollection
rooted at the element,
whose filter matches only tr
elements that are children
of the element.
The insertRow(index)
method must, when invoked on an
element table section, act as follows:
If index is less than −1 or greater than the
number of elements in the rows
collection, the method must throw an IndexSizeError
exception.
If index is −1 or
equal to the number of items in the rows
collection, the method must
create a tr
element, append it to the element table section, and return the newly created
tr
element.
Otherwise, the method must create a tr
element,
insert it as a child of the table section
element, immediately before the indexth
tr
element in the rows
collection, and finally must
return the newly created tr
element.
The deleteRow(index)
method must remove the indexth element in the rows
collection from its parent. If
index is less than zero or greater than or equal
to the number of elements in the rows
collection, the method must
instead throw an IndexSizeError
exception.
thead
elementtable
element, after any
caption
, and colgroup
elements and before any tbody
, tfoot
, and
tr
elements, but only if there are no other
thead
elements that are children of the
table
element.tr
and script-supporting elementsHTMLTableSectionElement
, as defined for
tbody
elements.The thead
element represents the block of rows that consist of the column labels
(headers) for the parent table
element, if the
thead
element has a parent and it is a
table
.
The thead
element takes part in the table
model.
This example shows a thead
element being used.
Notice the use of both th
and td
elements
in the thead
element: the first row is the headers,
and the second row is an explanation of how to fill in the
table.
<table> <caption> School auction sign-up sheet </caption> <thead> <tr> <th><label for=e1>Name</label> <th><label for=e2>Product</label> <th><label for=e3>Picture</label> <th><label for=e4>Price</label> <tr> <td>Your name here <td>What are you selling? <td>Link to a picture <td>Your reserve price <tbody> <tr> <td>Ms Danus <td>Doughnuts <td><img src="http://example.com/mydoughnuts.png" title="Doughnuts from Ms Danus"> <td>$45 <tr> <td><input id=e1 type=text name=who required form=f> <td><input id=e2 type=text name=what required form=f> <td><input id=e3 type=url name=pic form=f> <td><input id=e4 type=number step=0.01 min=0 value=0 required form=f> </table> <form id=f action="/auction.cgi"> <input type=button name=add value="Submit"> </form>
tfoot
elementtable
element, after any
caption
, colgroup
, and thead
elements and before any tbody
and tr
elements, but only if there are no other tfoot
elements that are children of the table
element.table
element, after any
caption
, colgroup
, thead
,
tbody
, and tr
elements, but only if there
are no other tfoot
elements that are children of the
table
element.tr
and script-supporting elementsHTMLTableSectionElement
, as defined for
tbody
elements.The tfoot
element represents the block of rows that consist of the column summaries
(footers) for the parent table
element, if the
tfoot
element has a parent and it is a
table
.
The tfoot
element takes part in the table
model.
tr
elementthead
element.tbody
element.tfoot
element.table
element, after any
caption
, colgroup
, and thead
elements, but only if there are no tbody
elements that
are children of the table
element.td
, th
, and script-supporting elementsinterface HTMLTableRowElement : HTMLElement { readonly attribute long rowIndex; readonly attribute long sectionRowIndex; readonly attribute HTMLCollection cells; HTMLElement insertCell(optional long index = -1); void deleteCell(long index); };
The tr
element represents a row of
cells in a table.
The tr
element takes part in the table model.
rowIndex
Returns the position of the row in the table's rows
list.
Returns −1 if the element isn't in a table.
sectionRowIndex
Returns the position of the row in the table section's rows
list.
Returns −1 if the element isn't in a table section.
cells
Returns an HTMLCollection
of the td
and th
elements of
the row.
insertCell
( [ index ] )Creates a td
element, inserts it into the table row at the position given by the
argument, and returns the td
.
The position is relative to the cells in the row. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the row.
If the given position is less than −1 or greater than the number of cells, throws an
IndexSizeError
exception.
deleteCell
(index)Removes the td
or th
element with the given position in the
row.
The position is relative to the cells in the row. The index −1 is equivalent to deleting the last cell of the row.
If the given position is less than −1 or greater than the index of the last cell, or
if there are no cells, throws an IndexSizeError
exception.
The rowIndex
attribute must, if the element has
a parent table
element, or a parent tbody
, thead
, or
tfoot
element and a grandparent table
element, return the index
of the tr
element in that table
element's rows
collection. If there is no such table
element,
then the attribute must return −1.
The sectionRowIndex
attribute must, if
the element has a parent table
, tbody
, thead
, or
tfoot
element, return the index of the tr
element in the parent
element's rows
collection (for tables, that's the HTMLTableElement.rows
collection; for table sections, that's the
HTMLTableRowElement.rows
collection). If there is no such
parent element, then the attribute must return −1.
The cells
attribute must return an
HTMLCollection
rooted at the tr
element, whose filter matches only
td
and th
elements that are children of the tr
element.
The insertCell(index)
method must act as follows:
If index is less than −1 or greater than the number of elements in
the cells
collection, the method must throw an
IndexSizeError
exception.
If index is equal to −1 or equal to the number of items in cells
collection, the method must create a td
element,
append it to the tr
element, and return the newly created td
element.
Otherwise, the method must create a td
element, insert it as a child of the
tr
element, immediately before the indexth td
or
th
element in the cells
collection, and finally
must return the newly created td
element.
The deleteCell(index)
method must remove the indexth element in the cells
collection from its parent. If index is less
than zero or greater than or equal to the number of elements in the cells
collection, the method must instead throw an
IndexSizeError
exception.
td
elementtr
element.colspan
rowspan
headers
interface HTMLTableDataCellElement : HTMLTableCellElement {};
The td
element represents a data cell in a table.
The td
element and its colspan
, rowspan
, and headers
attributes take part in the table model.
User agents, especially in non-visual environments or where displaying the table as a 2D grid
is impractical, may give the user context for the cell when rendering the contents of a cell; for
instance, giving its position in the table model, or listing the cell's header cells
(as determined by the algorithm for assigning header cells). When a cell's header
cells are being listed, user agents may use the value of abbr
attributes on those header cells, if any, instead of the contents of the header cells
themselves.
th
elementth
element is a sorting interface th
element: Interactive content.tr
element.header
, footer
, sectioning content, or heading content descendants, and if the th
element is a sorting interface th
element, no interactive content descendants.colspan
rowspan
headers
scope
abbr
sorted
interface HTMLTableHeaderCellElement : HTMLTableCellElement { attribute DOMString scope; attribute DOMString abbr; attribute DOMString sorted; void sort(); };
The th
element represents a header cell in a table.
The th
element may have a scope
content attribute specified. The scope
attribute is an
enumerated attribute with five states, four of which have explicit keywords:
row
keyword, which maps to the
row statecol
keyword, which maps to the
column staterowgroup
keyword, which maps to
the row group stateth
element's scope
attribute must
not be in the row group state if the element is not
anchored in a row group.colgroup
keyword, which maps to
the column group stateth
element's scope
attribute must
not be in the column group state if the element is
not anchored in a column group.The scope
attribute's missing value default is the
auto state.
The th
element may have an abbr
content attribute specified. Its value must be an alternative label for the header cell, to be
used when referencing the cell in other contexts (e.g. when describing the header cells that apply
to a data cell). It is typically an abbreviated form of the full header cell, but can also be an
expansion, or merely a different phrasing.
The sorted
attribute is used in the table
sorting model.
The th
element and its colspan
, rowspan
, headers
, and
scope
attributes take part in the table model.
The sort()
method is used in the table sorting
model.
The scope
IDL attribute must reflect
the content attribute of the same name, limited to only known values.
The abbr
and sorted
IDL attributes must reflect the
content attributes of the same name.
The following example shows how the scope
attribute's rowgroup
value affects which data cells a header cell
applies to.
Here is a markup fragment showing a table:
The tbody
elements in this example identify the range of the row groups.
<table> <caption>Measurement of legs and tails in Cats and English speakers</caption> <thead> <tr> <th> ID <th> Measurement <th> Average <th> Maximum <tbody> <tr> <td> <th scope=rowgroup> Cats <td> <td> <tr> <td> 93 <th scope=row> Legs <td> 3.5 <td> 4 <tr> <td> 10 <th scope=row> Tails <td> 1 <td> 1 </tbody> <tbody> <tr> <td> <th scope=rowgroup> English speakers <td> <td> <tr> <td> 32 <th scope=row> Legs <td> 2.67 <td> 4 <tr> <td> 35 <th scope=row> Tails <td> 0.33 <td> 1 </tbody> </table>
This would result in the following table:
ID | Measurement | Average | Maximum |
---|---|---|---|
Cats | |||
93 | Legs | 3.5 | 4 |
10 | Tails | 1 | 1 |
English speakers | |||
32 | Legs | 2.67 | 4 |
35 | Tails | 0.33 | 1 |
The header cells in row 1 ('ID', 'Measurement', 'Average' and 'Maximum') each apply only to the cells in their column.
The header cells with a scope=rowgroup
('Cats' and 'English speakers') apply to all the cells in their row group other
than the cells (to their left) in column 1:
The header 'Cats' (row 2, column 2) applies to the headers 'Legs' (row 3, column 2) and 'Tails' (row 4, column 2) and to the data cells in rows 2, 3 and 4 of the 'Average' and 'Maximum' columns.
The header 'English speakers' (row 5, column 2) applies to the headers 'Legs' (row 6, column 2) and 'Tails' (row 7, column 2) and to the data cells in rows 5, 6 and 7 of the 'Average' and 'Maximum' columns.
Each of the 'Legs' and 'Tails' header cells has a scope=row
and therefore apply to the data cells (to the right)
in their row, from the 'Average' and 'Maximum' columns.
td
and th
elementsThe td
and th
elements may have a colspan
content attribute specified, whose value must
be a valid non-negative integer greater than zero.
The td
and th
elements may also have a rowspan
content attribute specified, whose value must
be a valid non-negative integer. For this attribute, the value zero means that the
cell is to span all the remaining rows in the row group.
These attributes give the number of columns and rows respectively that the cell is to span. These attributes must not be used to overlap cells, as described in the description of the table model.
The td
and th
element may have a headers
content attribute specified. The headers
attribute, if specified, must contain a string consisting
of an unordered set of unique space-separated tokens that are
case-sensitive, each of which must have the value of an ID of a th
element taking part in the same table as the td
or th
element (as defined by the table model).
A th
element with ID id is
said to be directly targeted by all td
and th
elements in the
same table that have headers
attributes whose values include as one of their tokens
the ID id. A th
element A is said to be targeted by a th
or td
element
B if either A is directly targeted by B or if there exists an element C that is itself
targeted by the element B and A is directly
targeted by C.
A th
element must not be targeted by itself.
The colspan
, rowspan
, and headers
attributes take part in the table model.
The td
and th
elements implement interfaces that inherit from the
HTMLTableCellElement
interface:
interface HTMLTableCellElement : HTMLElement {
attribute unsigned long colSpan;
attribute unsigned long rowSpan;
[PutForwards=value] readonly attribute DOMSettableTokenList headers;
readonly attribute long cellIndex;
};
cellIndex
Returns the position of the cell in the row's cells
list.
This does not necessarily correspond to the x-position of the cell in the
table, since earlier cells might cover multiple rows or columns.
Returns −1 if the element isn't in a row.
The colSpan
IDL attribute must
reflect the colspan
content attribute. Its
default value is 1.
The rowSpan
IDL attribute must
reflect the rowspan
content attribute. Its
default value is 1.
The headers
IDL attribute must
reflect the content attribute of the same name.
The cellIndex
IDL attribute must, if the
element has a parent tr
element, return the index of the cell's element in the parent
element's cells
collection. If there is no such parent element,
then the attribute must return −1.
The various table elements and their content attributes together define the table model.
A table consists of cells aligned on a two-dimensional grid of
slots with coordinates (x, y). The grid is finite, and is either empty or has one or more slots. If the grid
has one or more slots, then the x coordinates are always in the range 0 ≤ x < xwidth, and the y coordinates are always in the
range 0 ≤ y < yheight. If one or both of xwidth and yheight are zero, then the
table is empty (has no slots). Tables correspond to table
elements.
A cell is a set of slots anchored at a slot (cellx, celly), and with
a particular width and height such that the cell covers
all the slots with coordinates (x, y) where cellx ≤ x < cellx+width and celly ≤ y < celly+height. Cells can either be data cells
or header cells. Data cells correspond to td
elements, and header cells
correspond to th
elements. Cells of both types can have zero or more associated
header cells.
It is possible, in certain error cases, for two cells to occupy the same slot.
A row is a complete set of slots from x=0 to x=xwidth-1, for a particular value of y. Rows usually
correspond to tr
elements, though a row group
can have some implied rows at the end in some cases involving
cells spanning multiple rows.
A column is a complete set of slots from y=0 to y=yheight-1, for a particular value of x. Columns can
correspond to col
elements. In the absence of col
elements, columns are
implied.
A row group is a set of rows anchored at a slot (0, groupy) with a particular height such that the row group
covers all the slots with coordinates (x, y) where 0 ≤ x < xwidth and groupy ≤ y < groupy+height. Row groups correspond to
tbody
, thead
, and tfoot
elements. Not every row is
necessarily in a row group.
A column group is a set of columns anchored at a slot (groupx, 0) with a particular width such that the column group
covers all the slots with coordinates (x, y) where groupx ≤ x < groupx+width and 0 ≤ y < yheight. Column
groups correspond to colgroup
elements. Not every column is necessarily in a column
group.
Row groups cannot overlap each other. Similarly, column groups cannot overlap each other.
A cell cannot cover slots that are from two or more row groups. It is, however, possible for a cell to be in multiple column groups. All the slots that form part of one cell are part of zero or one row groups and zero or more column groups.
In addition to cells, columns, rows, row groups, and column
groups, tables can have a caption
element
associated with them. This gives the table a heading, or legend.
A table model error is an error with the data represented by table
elements and their descendants. Documents must not have table model errors.
To determine which elements correspond to which slots in a table associated with a table
element, to determine the
dimensions of the table (xwidth and yheight), and to determine if there are any table model errors, user agents must use the following algorithm:
Let xwidth be zero.
Let yheight be zero.
Let pending tfoot
elements be a list of tfoot
elements, initially empty.
Let the table be the table represented
by the table
element. The xwidth and yheight variables give the table's
dimensions. The table is initially empty.
If the table
element has no children elements, then return the
table (which will be empty), and abort these steps.
Associate the first caption
element child of the table
element with
the table. If there are no such children, then it has no associated
caption
element.
Let the current element be the first element child of the
table
element.
If a step in this algorithm ever requires the current element to be advanced to the next child of the table
when
there is no such next child, then the user agent must jump to the step labeled end, near
the end of this algorithm.
While the current element is not one of the following elements, advance the current element to the next
child of the table
:
If the current element is a colgroup
, follow these
substeps:
Column groups: Process the current element according to the appropriate case below:
col
element childrenFollow these steps:
Let xstart have the value of xwidth.
Let the current column be the first col
element child
of the colgroup
element.
Columns: If the current column col
element has
a span
attribute, then parse its value using the
rules for parsing non-negative integers.
If the result of parsing the value is not an error or zero, then let span be that value.
Otherwise, if the col
element has no span
attribute, or if trying to parse the attribute's value
resulted in an error or zero, then let span be 1.
Increase xwidth by span.
Let the last span columns in
the table correspond to the current column
col
element.
If current column is not the last col
element child of
the colgroup
element, then let the current column be the
next col
element child of the colgroup
element, and return to
the step labeled columns.
Let all the last columns in the
table from x=xstart to
x=xwidth-1 form a new column group, anchored at the slot (xstart, 0), with width xwidth-xstart, corresponding to the colgroup
element.
col
element childrenIf the colgroup
element has a span
attribute, then parse its value using the rules for parsing non-negative
integers.
If the result of parsing the value is not an error or zero, then let span be that value.
Otherwise, if the colgroup
element has no span
attribute, or if trying to parse the attribute's
value resulted in an error or zero, then let span be 1.
Increase xwidth by span.
Let the last span columns in
the table form a new column
group, anchored at the slot (xwidth-span, 0), with width span, corresponding to the colgroup
element.
While the current element is not one of the following elements, advance the current element to the
next child of the table
:
If the current element is a colgroup
element, jump to the
step labeled column groups above.
Let ycurrent be zero.
Let the list of downward-growing cells be an empty list.
Rows: While the current element is not one of the following
elements, advance the current
element to the next child of the table
:
If the current element is a tr
, then run the algorithm
for processing rows, advance the current element to the next child of the table
, and return to the
step labeled rows.
Run the algorithm for ending a row group.
If the current element is a tfoot
, then add that element to
the list of pending tfoot
elements, advance the current element to the next
child of the table
, and return to the step labeled rows.
The current element is either a thead
or a
tbody
.
Run the algorithm for processing row groups.
Return to the step labeled rows.
End: For each tfoot
element in the list of pending
tfoot
elements, in tree order, run the algorithm for processing row
groups.
If there exists a row or column in the table containing only slots that do not have a cell anchored to them, then this is a table model error.
Return the table.
The algorithm for processing row groups, which is invoked by the set of steps above
for processing thead
, tbody
, and tfoot
elements, is:
Let ystart have the value of yheight.
For each tr
element that is a child of the element being processed, in tree
order, run the algorithm for processing rows.
If yheight > ystart, then let all the last rows in the table from y=ystart to y=yheight-1 form a new row group, anchored at the slot with coordinate (0, ystart), with height yheight-ystart, corresponding to the element being processed.
Run the algorithm for ending a row group.
The algorithm for ending a row group, which is invoked by the set of steps above when starting and ending a block of rows, is:
While ycurrent is less than yheight, follow these steps:
Increase ycurrent by 1.
Empty the list of downward-growing cells.
The algorithm for processing rows, which is invoked by the set of steps above for
processing tr
elements, is:
If yheight is equal to ycurrent, then increase yheight by 1. (ycurrent is never greater than yheight.)
Let xcurrent be 0.
If the tr
element being processed has no td
or th
element children, then increase ycurrent by 1, abort
this set of steps, and return to the algorithm above.
Let current cell be the first td
or th
element child
in the tr
element being processed.
Cells: While xcurrent is less than xwidth and the slot with coordinate (xcurrent, ycurrent) already has a cell assigned to it, increase xcurrent by 1.
If xcurrent is equal to xwidth, increase xwidth by 1. (xcurrent is never greater than xwidth.)
If the current cell has a colspan
attribute, then parse that attribute's
value, and let colspan be the result.
If parsing that value failed, or returned zero, or if the attribute is absent, then let colspan be 1, instead.
If the current cell has a rowspan
attribute, then parse that attribute's
value, and let rowspan be the result.
If parsing that value failed or if the attribute is absent, then let rowspan be 1, instead.
If rowspan is zero and the table
element's
Document
is not set to quirks mode, then let cell grows
downward be true, and set rowspan to 1. Otherwise, let cell grows downward be false.
If xwidth < xcurrent+colspan, then let xwidth be xcurrent+colspan.
If yheight < ycurrent+rowspan, then let yheight be ycurrent+rowspan.
Let the slots with coordinates (x, y) such that xcurrent ≤ x < xcurrent+colspan and ycurrent ≤ y < ycurrent+rowspan be covered by a new cell c, anchored at (xcurrent, ycurrent), which has width colspan and height rowspan, corresponding to the current cell element.
If the current cell element is a th
element, let this new
cell c be a header cell; otherwise, let it be a data cell.
To establish which header cells apply to the current cell element, use the algorithm for assigning header cells described in the next section.
If any of the slots involved already had a cell covering them, then this is a table model error. Those slots now have two cells overlapping.
If cell grows downward is true, then add the tuple {c, xcurrent, colspan} to the list of downward-growing cells.
Increase xcurrent by colspan.
If current cell is the last td
or th
element child in
the tr
element being processed, then increase ycurrent by 1, abort this set of steps, and return to the algorithm
above.
Let current cell be the next td
or th
element child
in the tr
element being processed.
Return to the step labeled cells.
When the algorithms above require the user agent to run the algorithm for growing downward-growing cells, the user agent must, for each {cell, cellx, width} tuple in the list of downward-growing cells, if any, extend the cell cell so that it also covers the slots with coordinates (x, ycurrent), where cellx ≤ x < cellx+width.
Each cell can be assigned zero or more header cells. The algorithm for assigning header cells to a cell principal cell is as follows.
Let header list be an empty list of cells.
Let (principalx, principaly) be the coordinate of the slot to which the principal cell is anchored.
headers
attribute specifiedTake the value of the principal cell's headers
attribute and split it on spaces, letting id list be the list of tokens
obtained.
For each token in the id list, if the
first element in the Document
with an ID equal to
the token is a cell in the same table, and that cell is not the
principal cell, then add that cell to header list.
headers
attribute specifiedLet principalwidth be the width of the principal cell.
Let principalheight be the height of the principal cell.
For each value of y from principaly to principaly+principalheight-1, run the internal algorithm for scanning and assigning header cells, with the principal cell, the header list, the initial coordinate (principalx,y), and the increments Δx=−1 and Δy=0.
For each value of x from principalx to principalx+principalwidth-1, run the internal algorithm for scanning and assigning header cells, with the principal cell, the header list, the initial coordinate (x,principaly), and the increments Δx=0 and Δy=−1.
If the principal cell is anchored in a row group, then add all header cells that are row group headers and are anchored in the same row group with an x-coordinate less than or equal to principalx+principalwidth-1 and a y-coordinate less than or equal to principaly+principalheight-1 to header list.
If the principal cell is anchored in a column group, then add all header cells that are column group headers and are anchored in the same column group with an x-coordinate less than or equal to principalx+principalwidth-1 and a y-coordinate less than or equal to principaly+principalheight-1 to header list.
Remove all the empty cells from the header list.
Remove any duplicates from the header list.
Remove principal cell from the header list if it is there.
Assign the headers in the header list to the principal cell.
The internal algorithm for scanning and assigning header cells, given a principal cell, a header list, an initial coordinate (initialx, initialy), and Δx and Δy increments, is as follows:
Let x equal initialx.
Let y equal initialy.
Let opaque headers be an empty list of cells.
Let in header block be true, and let headers from current header block be a list of cells containing just the principal cell.
Let in header block be false and let headers from current header block be an empty list of cells.
Loop: Increment x by Δx; increment y by Δy.
For each invocation of this algorithm, one of Δx and Δy will be −1, and the other will be 0.
If either x or y is less than 0, then abort this internal algorithm.
If there is no cell covering slot (x, y), or if there is more than one cell covering slot (x, y), return to the substep labeled loop.
Let current cell be the cell covering slot (x, y).
Set in header block to true.
Add current cell to headers from current header block.
Let blocked be false.
If there are any cells in the opaque headers list anchored with the same x-coordinate as the current cell, and with the same width as current cell, then let blocked be true.
If the current cell is not a column header, then let blocked be true.
If there are any cells in the opaque headers list anchored with the same y-coordinate as the current cell, and with the same height as current cell, then let blocked be true.
If the current cell is not a row header, then let blocked be true.
If blocked is false, then add the current cell to the headers list.
Set in header block to false. Add all the cells in headers from current header block to the opaque headers list, and empty the headers from current header block list.
Return to the step labeled loop.
A header cell anchored at the slot with coordinate (x, y) with width width and height height is said to be a column header if any of the following conditions are true:
scope
attribute is in the column state, orscope
attribute is in the auto state, and there are no data cells in any of the cells
covering slots with y-coordinates y .. y+height-1.A header cell anchored at the slot with coordinate (x, y) with width width and height height is said to be a row header if any of the following conditions are true:
scope
attribute is in the row state, orscope
attribute is in the auto state, the cell is not a column header, and
there are no data cells in any of the cells covering slots with x-coordinates
x .. x+width-1.A header cell is said to be a column group header if its scope
attribute is in the column
group state.
A header cell is said to be a row group header if its scope
attribute is in the row
group state.
A cell is said to be an empty cell if it contains no elements and its text content, if any, consists only of White_Space characters.
The sortable
attribute on
table
elements is a boolean attribute. When present, it indicates that
the user agent is to allow the user to sort the table
.
To make a column sortable in a table
with a thead
, the column needs
to have th
element that does not span multiple
columns in a thead
above any rows that it is to sort.
To make a column sortable in a table
without a thead
, the column
needs to have th
element that does not span multiple
columns in the first tr
element of the table
, where that
tr
element is not in a tfoot
.
When the user selects a column by which to sort, the user agent sets the th
element's sorted
attribute. This attribute can also
be set manually, to indicate that the table should be automatically sorted, even when scripts
modify the page on when the page is loaded.
The sorted
attribute, if specified, must have a value that
is a set of space-separated tokens consisting of optionally a token whose value is an
ASCII case-insensitive match for the string "reversed
", and optionally a token whose value
is a valid non-negative integer greater than zero, in either order.
In other words, ignoring spaces and case, the sorted
attribute's value can be empty, "reversed
", "1
", "reversed 1
", or
"1 reversed
", where "1" is any number equal to or greater than 1.
While one or more th
elements in the table have a sorted
attribute, the user agent will keep the table's data rows
sorted. The value of the attribute controls how the column is used in determining the sort order.
The reversed
keyword means that the column sort
direction is reversed, rather than normal, which is the default if the keyword
is omitted. The number, if present, indicates the column key ordinality; if the number
is omitted, the column is the primary key, as if the value 1 had been specified.
Thus, sorted="1"
indicates the table's primary key, sorted="2"
its secondary key, and so forth.
A sorting-capable th
element is a th
element that matches
all the following conditions simultaneously:
It corresponds to a cell whose width is 1.
(Specifically, a header cell, since this is a th
element.)
There is no cell that corresponds to another
sorting-capable th
element that covers slots in the same column but on a higher (earlier) row.
If the cell's table has
a row group corresponding to a thead
element, the cell is in a row
group that corresponds to the first thead
element of the cell's table.
Otherwise: the cell is not in a row group corresponding to a tfoot
element, and
the cell is in the first row
of the table.
In other words, each column can have one
sorting-capable th
element; this will be the highest th
in
a thead
that spans no other columns, or, if there is no thead
, the
th
in the first row (that is not in a tfoot
), assuming it spans no
columns.
The sorting-capable th
elements of the table
element table are the sorting-capable
th
elements whose cell's table is table.
A table
element table is a sorting-capable
table
element if there are one or more sorting-capable th
elements of the table
element table.
A th
element is a sorting-enabled th
element if it is a
sorting-capable th
element and it has a sorted
attribute.
The sorting-enabled th
elements of the table
element table are the sorting-enabled
th
elements whose cell's table is table.
A table
element table is a sorting-enabled
table
element if there are one or more sorting-capable th
elements of the table
element table, and at least one of
them is a sorting-enabled th
element (i.e. at least one has a sorted
attribute).
A table
element is a table
element with a user-agent exposed
sorting interface if it is a sorting-capable table
element and has
a sortable
attribute specified.
A sorting interface th
element is a sorting-capable
th
element whose cell's table is a table
element with a user-agent exposed
sorting interface.
Each table
element has a currently-sorting flag, which must initially
be false.
The sorted
attribute must not be specified on
th
elements that are not sorting-capable
th
elements. The sortable
attribute
must not be specified on table
elements that are not sorting-capable table
elements.
To determine a th
element's sorted
attribute's
column sort direction and column key ordinality, user agents must use
the following algorithm:
Let direction be normal.
Let have explicit direction be false.
Let ordinality be 1.
Let have explicit ordinality be false.
Let tokens be the result of splitting the attribute's value on spaces.
For each token token in tokens, run the appropriate steps from the following list:
reversed
"Let direction be reversed and have explicit direction be true.
Parse token as an integer. If this resulted in an error or the value zero, then ignore the token. Otherwise, set ordinality to the parsed value, and set have explicit ordinality to true.
Ignore the token.
The column sort direction is the value of direction, and the column key ordinality is the value of ordinality.
A table
must not have two th
elements whose sorted
attribute have the same column key
ordinality.
The table sorting algorithm, which is applied to a table
, is as
follows:
Let table be the table
element being sorted.
If table's currently-sorting flag is true, then abort these steps.
Set table's currently-sorting flag to true.
Fire a simple event named sort
that is
cancelable at table.
If the event fired in the previous step was canceled, then jump to the step labeled end below.
If table is not now a sorting-enabled table
element, then jump to the step labeled end below.
Even if table was a sorting-enabled table
element when the algorithm was invoked, the DOM might have been entirely changed by the
event handlers for the sort
event, so this has to be verified at
this stage, not earlier.
Let key heading cells be the sorting-enabled th
elements of the table
element table.
Sort key heading cells in ascending order of the column key
ordinality of their sorted
attributes, with those
having the same column key ordinality being sorted in tree order.
Let row collection cursor be a pointer to an element, initially pointing
at the first child of table that is after table's first
thead
, if any, and that is either a tbody
or a tr
element, assuming there is one. If there is no such child, then jump to the step labeled
end below.
If table has no row group
corresponding to a thead
element, then set ignore first group to
true. Otherwise, set it to false.
Row loop: Let rows be an empty list of tr
elements.
Run the appropriate steps from the following list:
tr
element
Collect: Append the element pointed to by row collection cursor to rows.
If there are no tr
or tbody
children of table that are later siblings of the element pointed to by row
collection cursor, or if the next such child is a tbody
element, then jump
to the step labeled group below.
Let row collection cursor point to the next tr
child
of table that is a later sibling of the element pointed to by row collection cursor.
Return to the step labeled collect above.
tbody
element
Place all the tr
element children of the element pointed to by row collection cursor into rows, in tree
order.
If rows is empty, jump to the step labeled increment loop below.
Group: Let groups be an empty list of groups of tr
elements.
Let group be an empty group of tr
elements.
Let group cursor be a pointer to an element, initially pointing at the
first tr
element in rows.
Start group: Let pending rows in group be 1.
Group loop: Append the tr
element pointed to by group
cursor to group.
If there are any cells whose highest row's element is the one pointed to by group cursor, then let tallest height be the number of rows covered by the tallest such cell.
If tallest height is greater than pending rows in group then set pending rows in group to tallest height.
Decrement pending rows in group by one.
Let group cursor point to the next tr
element in rows, if any; otherwise, let it be null.
If group cursor is not null and pending rows in group is not zero, return to the step labeled group loop.
Append a new group to groups consisting of the tr
elements in group.
Empty group.
If group cursor is not null, then return to the step labeled start group.
If ignore first group is true, then drop the first group in groups and set ignore first group to false.
Drop leading header groups: If groups is now empty, jump to the step labeled increment loop below.
If the first group of groups consists of tr
elements
whose element children are all th
elements, then drop the first group in groups and return to the previous step (labeled drop leading header
groups).
Let insertion point be a placeholder in a DOM tree, which can be used
to reinsert nodes at a specific point in the DOM. Insert insertion point into
the parent of the first tr
element of the first group in groups,
immediately before that tr
element.
Sort the groups in groups, using the following algorithm to decide the relative order of any two groups a and b (the algorithm either returns that a comes before b, or that b comes before a):
Let key index be an index into key heading cells, initially denoting the first element in the list.
Let direction be a sort direction, initially ascending. Its other possible value is descending. When direction is toggled, that means that if its value is ascending, it must be changed to descending, and when its value is descending, it must be changed to ascending.
Column loop: Let th be the key indexth
th
in key heading cells.
If th's sorted
attribute's
column sort direction is reversed, then toggle direction.
Let tentative order be the result of comparing two row groups
using the th
element th, with a and
b as the rows.
If tentative order is not "equal", then jump to the step labeled return below.
Increment key index.
If key index still denotes a th
element in key heading cells, then jump back to the step above labeled column
loop.
If a's tr
elements precede b's in
tree order, then let tentative order be "a before b".
Otherwise, let tentative order be "b before a".
Return: Return the relative order given by the matching option from the following list:
When the user agent is required to compare two row groups using the th
element th,
with a and b being the two row groups respectively, the
user agent must run the following steps:
Let x be the x-coordinate of the slots that
th
covers in its table.
Let cella be the element corresponding to the cell in the first row of group a that covers the slot in that row whose x-coordinate is x.
Let cellb be the element corresponding to the cell in the first row of group b that covers the slot in that row whose x-coordinate is x.
In either case, if there's no cell that actually covers the slot, then use the value null instead.
Let typea and valuea be the type and value of the cell cella, as defined below.
Let typeb and valueb be the type and value of the cell cellb, as defined below.
The type and value of the cell cell are computed as follows.
If cell is null, then the type is "string" and the value is the empty string; abort these steps.
If, ignoring inter-element whitespace and nodes other than
Element and Text nodes, cell has only one child
and that child is a data
element, then the value is the value of that
data
element's value
attribute, if there is
one, or the empty string otherwise; the type is "string".
If, ignoring inter-element whitespace and nodes other than
Element and Text nodes, cell has only one child
and that child is a progress
element, then the value is the value of that
progress
element's value
attribute, if
there is one, or the empty string otherwise; the type is "string".
If, ignoring inter-element whitespace and nodes other than
Element and Text nodes, cell has only one child
and that child is a meter
element, then the value is the value of that
meter
element's value
attribute, if there is
one, or the empty string otherwise; the type is "string".
If, ignoring inter-element whitespace and nodes other than
Element and Text nodes, cell has only one
child and that child is a time
element, then the value is the
machine-readable equivalent of the element's contents, if any, and the type is
the kind of value that is thus obtained
(a month,
a date,
a yearless date,
a time,
a local date and time,
a time-zone offset,
a global date and time,
a week,
a year, or
a duration);
abort these steps after completing this one.
If there is no machine-readable equivalent, then the type is "string" and the value is the empty string.
If the type is a month, a date, a week, or a year, then change the value to be the instant in time (with no time zone) that describes the earliest moment that the value represents, and change the type to be a local date and time.
For example, if the cell was
<td><time>2011-11</time>
then for sorting purposes the value is
interpreted as "2011-11-01T00:00:00.000" and the type is treated as a local date and time rather than a month.
Similarly, if the cell was <td><time
datetime="2014">MMXIV</time>
then for sorting purposes the value is interpreted as
"2014-01-01T00:00:00.000" and the type is treated as a local date and time rather than a year.
The value is the element's textContent
. The type is "string".
If typea and typeb are not equal, then: return "a before b" if typea is earlier in the following list than typeb, otherwise, return "b before a"; then, abort these steps.
If valuea and valueb are equal, then return "equal" and abort these steps.
If typea and typeb are not "string", then: if valuea is earlier than valueb then return "a before b" and abort these steps, otherwise, return "b before a" and abort these steps.
Values sort in their natural order, with the following additional constraints:
For time values, 00:00:00.000 is the earliest value and 23:59:59.999 is the latest value.
For yearless date values, 01-01 is the earliest value and 12-31 is the latest value; 02-28 is earlier than 02-29 which is earlier than 03-01.
Values that are local date and time compare as if they were in the same time zone.
For time-zone offset values, -23:59 is the earliest value and +23:59 is the latest value.
Let componentsa be the result of parsing the sort key valuea.
Let componentsb be the result of parsing the sort key valueb.
As described below, componentsa and componentsb are tuples consisting of a list of n numbers, a list of n number strings, a list of n+1 non-numeric strings, and a list of 2n+1 raw strings, for any non-negative integer value of n (zero or more).
Let order be the result of a locale-specific string comparison of componentsa's first non-numeric string and componentsb's first non-numeric string, in the context of th.
If order is not "equal" then return order and abort these steps.
If componentsa and componentsb both have exactly one number, then run these substeps:
If componentsa's number is less than componentsb's number, return "a before b".
If componentsb's number is less than componentsa's number, return "b before a".
Let order be the result of a locale-specific string comparison of componentsa's second non-numeric string and componentsb's second non-numeric string, in the context of th.
If order is not "equal" then return order and abort these steps.
Let order be the result of a locale-specific string comparison of componentsa's number string and componentsb's number string, in the context of th.
If order is not "equal" then return order and abort these steps.
Otherwise, run these substeps:
If componentsa has zero numbers but componentsb has more than zero numbers, return "a before b".
If componentsb has zero numbers but componentsa has more than zero numbers, return "b before a".
If componentsa has one number, return "a before b".
If componentsb has one number, return "b before a".
If componentsa and componentsb have more than one number, run these substeps:
Let count be the smaller of the number of numbers in componentsa and the number of numbers in componentsb.
For each number in componentsa and componentsb from the first to the countth, in order: if componentsa's number is less than componentsb's number, then return "a before b" and abort these steps; otherwise, if componentsb's number is less than componentsa's number, return "b before a" and abort these steps.
If componentsa has fewer numbers than componentsb, return "a before b" and abort these steps.
If componentsb has fewer numbers than componentsa, return "b before a" and abort these steps.
Let index be zero.
String loop: Let order be the result of a locale-specific string comparison of componentsa's indexth number string and componentsb's indexth number string, in the context of th.
If order is not "equal" then return order and abort these steps.
Increment index.
Let order be the result of a locale-specific string comparison of componentsa's indexth separator string and componentsb's indexth separator string, in the context of th.
If order is not "equal" then return order and abort these steps.
If index is less than the number of numbers in componentsa and componentsb, return to the step labeled string loop.
Let index be zero.
Final loop: Let order be the result of a raw string comparison of componentsa's nth raw string and componentsb's nth raw string.
If order is not "equal" then return order and abort these steps.
Increment index.
If index is less than the number of raw strings in componentsa and componentsb, return to the step labeled final loop.
Return "equal".
Let new order be a list of tr
elements consisting of the
tr
elements of all the groups in the newly ordered groups, with
the tr
elements being in the same order as the groups to which they belong are in
groups, and the tr
elements within each such group themselves
being ordered in tree order.
Remove all the tr
elements in new order from their parents, in tree order.
Insert all the tr
elements in new order into the DOM at the location of insertion point, in
the order these elements are found in new order.
Remove insertion point from the DOM.
Increment loop: If there are no tr
or tbody
children of
table that are later siblings of the element pointed to by row
collection cursor, then jump to the step labeled end below.
Let row collection cursor point to the next tr
or
tbody
child of table that is a later sibling of the element
pointed to by row collection cursor.
Return to the step labeled row loop above.
End: Set table's currently-sorting flag to false.
When a user agent is to parse the sort key value, it must run the following steps. These return a tuple consisting of a list of n numbers, a list of n number strings, a list of n+1 non-numeric strings, and a list of 2n+1 raw strings, respectively, for any non-negative integer value of n (zero or more).
Let raw strings be a list of strings initially containing just one entry, an empty string.
Let negatives prejudiced be false.
Let decimals prejudiced be false.
Let exponents prejudiced be false.
Let buffer be the empty string.
Let index be zero.
Let mode be "separator".
When a subsequent step in this algorithm says to push the buffer, the user agent must run the following substeps:
Add an entry to raw strings that consists of the value of buffer.
Add an entry to raw strings that is the empty string.
Decrement index by one.
Set mode to "separator".
Let checkpoint buffer be the empty string.
Let checkpoint index be zero.
When a subsequent step in this algorithm says to checkpoint, the user agent must run the following substeps:
Set the checkpoint buffer to the value of buffer.
Set the checkpoint index to the value of index.
When a subsequent step in this algorithm says to push the checkpoint, the user agent must run the following substeps:
Add an entry to raw strings that consists of the value of checkpoint buffer.
Add an entry to raw strings that is the empty string.
Decrement index by one.
Set mode to "separator".
Run through the following steps repeatedly until the condition in the last step is met.
Top of loop: If index is equal to or greater than the number of characters in value, let c be EOF. Otherwise, let c be the indexth character in value.
Run the appropriate steps from the following list:
Run the appropriate substeps from the following list:
Set negatives prejudiced to false.
Set decimals prejudiced to false.
Set exponents prejudiced to false.
Append c to the last entry in raw strings.
Set buffer to the value of c.
Set mode to "negative".
Set buffer to the value of c.
Set mode to "leading-decimal".
Set buffer to the value of c.
Set mode to "integral".
Set exponents prejudiced to true.
Append c to the last entry in raw strings.
Do nothing.
Append c to the last entry in raw strings.
Run the appropriate substeps from the following list:
Set negatives prejudiced to true.
Append buffer to the last entry in raw strings.
Append c to the last entry in raw strings.
Set mode to "separator".
Append c to buffer.
Set mode to "leading-decimal".
Append c to buffer.
Set mode to "integral".
Append buffer to the last entry in raw strings.
Decrement index by one.
Set mode to "separator".
Run the appropriate substeps from the following list:
Set negatives prejudiced to true.
Append c to buffer.
Set mode to "decimal".
Append c to the last entry in raw strings.
Append c to buffer.
Set mode to "exponent".
Run the appropriate substeps from the following list:
Append c to buffer.
Set mode to "decimal".
Append buffer to the last entry in raw strings.
Decrement index by one.
Set mode to "separator".
Run the appropriate substeps from the following list:
Set negatives prejudiced to true.
Set decimals prejudiced to true.
Append c to buffer.
Append c to buffer.
Set mode to "exponent".
Run the appropriate substeps from the following list:
Append c to buffer.
Set mode to "exponent-negative".
Set decimals prejudiced to true.
Append c to buffer.
Set mode to "exponent-number".
Set exponents prejudiced to true.
Run the appropriate substeps from the following list:
Set negatives prejudiced to true.
Set decimals prejudiced to true.
Append c to buffer.
Set mode to "exponent-negative-number".
Set exponents prejudiced to true.
Run the appropriate substeps from the following list:
Set negatives prejudiced to true.
Set decimals prejudiced to true.
Append c to buffer.
Set exponents prejudiced to true.
Run the appropriate substeps from the following list:
Set negatives prejudiced to true.
Set decimals prejudiced to true.
Append c to buffer.
Set exponents prejudiced to true.
Increment index by one.
If index is greater than the number of characters in value, stop repeating these substeps and continue along the overall steps. Otherwise, return to the step labeled top of loop.
Let numbers be an empty list.
Let number strings be an empty list.
Let non-numeric strings be an empty list.
For each even-numbered entry in raw strings, in order, starting from the first entry (numbered 0), append an entry to non-numeric strings that consists of the result of trimming and collapsing the value of the entry.
If raw strings has more than one entry, then, for each odd-numbered entry in raw strings, in order, starting from the second entry (numbered 1), append an entry to number strings that consists of the value of the entry, and append an entry to number strings that consists of the result of parsing the value of the entry using the rules for parsing floating-point number values.
Return numbers, number strings, non-numeric strings, and raw strings respectively.
When the user agent is required by the step above to perform a locale-specific string comparison of two strings a and b in the context of an element e, the user agent must apply the Unicode Collation Algorithm, using the Default Unicode Collation Element Table as customized for the language of the element e in the Common Locale Data Repository, to the strings a and b, ignoring case. If the result of this algorithm places a first, then return "a before b"; if it places b first, then return "b before a"; otherwise, if they compare as equal, then return "equal". [UCA] [CLDR]
When the user agent is required by the step above to perform a raw string comparison of two strings a and b, the user agent must apply the Unicode Collation Algorithm, using the Default Unicode Collation Element Table without customizations, to the strings a and b. If the result of this algorithm places a first, then return "a before b"; if it places b first, then return "b before a"; otherwise, if they compare as equal, then return "equal". [UCA]
Where the steps above refer to trimming and collapsing a string value, it means running the following algorithm:
Strip leading and trailing whitespace from value.
Replace any sequence of one or more space characters in value with a single U+0020 SPACE character.
When any of the descendants of a sorting-enabled table
element change
in any way (including attributes changing), and when a table
element becomes a
sorting-enabled table
element, the table
element is said to
become a table with a pending sort.
When the user agent is to sort the tables with pending sorts, which happens during the perform a microtask checkpoint algorithm, the user agent must run the following algorithm:
Let tables be a list of each table
in the unit of
related similar-origin browsing contexts that is a table with a pending sort,
in the order that they became such, with those that become such at the same time being listed in
tree order.
Let all the table
elements in tables no longer be tables with a pending sort.
Apply the table sorting algorithm to each table
in tables, in order.
When the user agent is to set the sort key to a th
element target, it must run the following algorithm:
Let table be the table
of the table of which target is a header cell.
If th
is a sorting-enabled th
element whose
column key ordinality is 1, then: if its column sort direction is
normal, set that element's sorted
attribute to the
string "reversed
", otherwise, set it to the empty string; then, abort these
steps.
Let current headers be the sorting-enabled th
elements of the table
element table, excluding target.
Sort current headers by their sorted
attributes' column key ordinality, in ascending
order, with elements that have the same column key ordinality being sorted in
tree order.
Let level be 2.
For each th
element th in current
headers, in order, run the following substeps:
If th's sorted
attribute's
column sort direction is normal, then set th's sorted
attribute to a valid integer whose value is
level. Otherwise, set it to the concatenation of the string "reversed
", a U+0020 SPACE character, and a valid integer whose
value is level.
Increment level by 1.
Set target's sorted
attribute to
the empty string.
The activation behavior of a sorting interface th
element is to set the sort key to the th
element.
The table
will be sorted the next time the user agent performs a microtask checkpoint.
sort
()Act as if the user had indicated that this was to be the new primary sort column.
The table
won't actually be sorted until the script terminates.
stopSorting
()Removes all the sorted
attributes that are causing the
table to automatically sort its contents, if any.
The th
element's sort()
method, when
invoked, must run the following steps:
If the th
element is not a sorting-capable th
element, then abort these steps.
Set the sort key to the th
element.
The table
will be sorted the next time the user agent performs a microtask checkpoint.
The table
element's stopSorting()
method, when invoked, must remove
the sorted
attribute of all the sorting-enabled
th
elements of the table element on which the method was invoked.
This section is non-normative.
The following shows how might one mark up the bottom part of table 45 of the Smithsonian physical tables, Volume 71:
<table> <caption>Specification values: <b>Steel</b>, <b>Castings</b>, Ann. A.S.T.M. A27-16, Class B;* P max. 0.06; S max. 0.05.</caption> <thead> <tr> <th rowspan=2>Grade.</th> <th rowspan=2>Yield Point.</th> <th colspan=2>Ultimate tensile strength</th> <th rowspan=2>Per cent elong. 50.8mm or 2 in.</th> <th rowspan=2>Per cent reduct. area.</th> </tr> <tr> <th>kg/mm<sup>2</sup></th> <th>lb/in<sup>2</sup></th> </tr> </thead> <tbody> <tr> <td>Hard</td> <td>0.45 ultimate</td> <td>56.2</td> <td>80,000</td> <td>15</td> <td>20</td> </tr> <tr> <td>Medium</td> <td>0.45 ultimate</td> <td>49.2</td> <td>70,000</td> <td>18</td> <td>25</td> </tr> <tr> <td>Soft</td> <td>0.45 ultimate</td> <td>42.2</td> <td>60,000</td> <td>22</td> <td>30</td> </tr> </tbody> </table>
This table could look like this:
Grade. | Yield Point. | Ultimate tensile strength | Per cent elong. 50.8 mm or 2 in. | Per cent reduct. area. | |
---|---|---|---|---|---|
kg/mm2 | lb/in2 | ||||
Hard | 0.45 ultimate | 56.2 | 80,000 | 15 | 20 |
Medium | 0.45 ultimate | 49.2 | 70,000 | 18 | 25 |
Soft | 0.45 ultimate | 42.2 | 60,000 | 22 | 30 |
The following shows how one might mark up the gross margin table on page 46 of Apple, Inc's 10-K filing for fiscal year 2008:
<table> <thead> <tr> <th> <th>2008 <th>2007 <th>2006 <tbody> <tr> <th>Net sales <td>$ 32,479 <td>$ 24,006 <td>$ 19,315 <tr> <th>Cost of sales <td> 21,334 <td> 15,852 <td> 13,717 <tbody> <tr> <th>Gross margin <td>$ 11,145 <td>$ 8,154 <td>$ 5,598 <tfoot> <tr> <th>Gross margin percentage <td>34.3% <td>34.0% <td>29.0% </table>
This table could look like this:
2008 | 2007 | 2006 | |
---|---|---|---|
Net sales | $ 32,479 | $ 24,006 | $ 19,315 |
Cost of sales | 21,334 | 15,852 | 13,717 |
Gross margin | $ 11,145 | $ 8,154 | $ 5,598 |
Gross margin percentage | 34.3% | 34.0% | 29.0% |
The following shows how one might mark up the operating expenses table from lower on the same page of that document:
<table> <colgroup> <col> <colgroup> <col> <col> <col> <thead> <tr> <th> <th>2008 <th>2007 <th>2006 <tbody> <tr> <th scope=rowgroup> Research and development <td> $ 1,109 <td> $ 782 <td> $ 712 <tr> <th scope=row> Percentage of net sales <td> 3.4% <td> 3.3% <td> 3.7% <tbody> <tr> <th scope=rowgroup> Selling, general, and administrative <td> $ 3,761 <td> $ 2,963 <td> $ 2,433 <tr> <th scope=row> Percentage of net sales <td> 11.6% <td> 12.3% <td> 12.6% </table>
This table could look like this:
2008 | 2007 | 2006 | |
---|---|---|---|
Research and development | $ 1,109 | $ 782 | $ 712 |
Percentage of net sales | 3.4% | 3.3% | 3.7% |
Selling, general, and administrative | $ 3,761 | $ 2,963 | $ 2,433 |
Percentage of net sales | 11.6% | 12.3% | 12.6% |