XForms 1.1

1 Introduction

1.1 Reading the Specification

The specification has been written with various modes of presentation in mind. In case of a discrepancy, the online electronic version is considered the authoritative version of the document.

This document uses the terms must, must not, required, shall, shall not, recommended, should, should not, may, and optional in accord with [RFC 2119].

1.2 How the Specification is Organized

The specification is organized as a set of changes relative to [XForms 1.0]. Chapters are arranged by topic.

1.3 Documentation Conventions

Throughout this document, the following namespace prefixes and corresponding namespace identifiers are used:

xforms: The XForms 1.1 namespace (http://www.w3.org/2004/xforms/)
html: The XHTML 2.0 namespace
ev: The XML Events namespace [XML Events]
my: Any user defined namespace

This is only a convention; any namespace prefix may be used in practice.

The following typographical conventions are used to present technical material in this document.

The XML representations of various elements within XForms are presented using the syntax for Abstract Modules in XHTML Modularization [XHTML Modularization].

Examples are set off typographically:

Example: Example item

Example Item

References to external documents appear as follows: [Sample Reference] with links to the references section of this document.

Sample Reference: Reference - linked to from above.

The following typesetting convention is used for non-normative commentary:

Note:

A gentle explanation to readers.

Editorial note: Editorial Note Name
Editorial commentary, not intended for final publication.

Issue (sample-implementation-issue):

Issue-Name

A specific issue for which input from implementors is requested, for example as part of the Candidate Recommendation phase.

Resolution:

None recorded.

2 XForms Core

2.1 Namespaces for XForms 1.1

The XML Schema definition of XForms 1.1 is available in two forms.

2.1.1 No-namespace schema for XForms 1.1

XForms 1.1 includes a schema with no target namespace which allows XForms to be incorporated into another namespace using the XML Schema include facility. This kind of schema is sometimes referred to as a Chameleon schema.

Example: XForms 1.1 "included" in XHTML 2

<switch>
  <case id="in" selected="true">
    <input ref="yourname">
      <label>Please tell me your name</label>
      <toggle ev:event="DOMActivate" case="out"/>
    </input>
  </case>
  <case id="out" selected="false">
    <p>Hello <output ref="yourname" />
      <trigger id="editButton">
        <label>Edit</label>
        <toggle ev:event="DOMActivate" case="in"/>
      </trigger>
    </p>
  </case>
</switch>

This example is a redefinition of one provided in the XForms 1.0 Recommendation. In XForms 1.0 the <p> element would have required a namespace prefix to indicate that is comes from the XHTML namespace.

2.1.2 Namespaced schema for XForms 1.1

XForms 1.1 also includes a schema which has a target namespace specified and as such is compatible with the XForms 1.0 definition. This schema includes all of the no-namespace schema and assigns is a target namespace of http://www.w3.org/2004/xforms/

Example: XForms 1.1 used in combination with XHTML 1

<switch xmlns="http://www.w3.org/2004/xforms/">
  <case id="in" selected="true">
    <input ref="yourname">
      <label>Please tell me your name</label>
      <toggle ev:event="DOMActivate" case="out"/>
    </input>
  </case>
  <case id="out" selected="false">
    <html:p>Hello <output ref="yourname" />
      <trigger id="editButton">
        <label>Edit</label>
        <toggle ev:event="DOMActivate" case="in"/>
      </trigger>
    </html:p>
  </case>
</switch>

The above example is unchanged from the specification in XForms 1.0 with the exception that the new XForms 1.1 namespace is used (in the example, the prefixes html and ev are defined by an ancestor of the switch element).

2.2 Utility Functions used in XPath Expressions

2.2.1 The power() Function

number power(number, number)

Raises the first argument to the power of the second argument, returning the result. If the calculation does not result in a real number, then NaN is returned.

Examples:

power(-1, 0.5)

returns NaN.

if (prin>0 and dur>0 and rate>0, prin*rate/(1-power(1+rate, -dur)), 0)

returns a compounded interest payment value given a non-zero principal (prin), duration (dur) and periodic interest rate (rate).

2.2.2 The luhn() Function

boolean luhn(string)

If the string parameter conforms to the pattern restriction of the xforms:ID-card-number type, then this function applies the luhn formula described in [ISO 7812-1:2000] and returns true if the number satisfies the formula. Otherwise, false is returned.

Examples (see also 2.5 New Data Type: ID Card Number):

luhn(.)

returns true if and only if the context node contains a string that contains 12 to 19 digits and satisfies the formula.

luhn('123')

returns false.

2.2.3 The current() Function

node-set current()

Returns the context node used to initialize the evaluation of the containing XPath expression.

Examples:

For the following instance data:

<xforms:instance xmlns="">
	<converter>
		<amount>100</amount>
		<currency>jpy</currency>
		<convertedAmount></convertedAmount>
	</converter>
</xforms:instance>

<xforms:instance xmlns="" id="convTable">
	<convTable date="20040212" currency="cdn">
		<rate currency="eur">0.59376</rate>
		<rate currency="mxn">8.37597</rate>
		<rate currency="jpy">80.23451</rate>
		<rate currency="usd">0.76138</rate>
	</convTable>
</xforms:instance>

and the following value calculation bind:

<bind nodeset="convertedAmount" 
      calculate="../amount * 
                 instance('convTable')/rate[@currency=current()/../currency]"/>

the content value of /converter/convertedAmount is the product of /converter/amount and the conversion table rate given by the rate element whose currency attribute value matches the content of /converter/currency.

For the following instance data:

<xforms:instance xmlns="" id="i1">
	<months>
		<mon>01</mon>
		<mon>02</mon>
		<mon>03</mon>
	</months>
</xforms:instance>
<xforms:instance xmlns="" id="i2">
	<months>
		<month code="01">Jan</month>
		<month code="02">Feb</month>
		<month code="03">Mar</month>
	</months>
</xforms:instance>

and the following repeat structure:

<repeat nodeset="mon">
	<output value="instance('i2')/month[@code = current()]/>
</repeat>

the output should contain Jan Feb Mar.

2.2.4 The choose() Function

object choose(boolean, object, object)

If the boolean parameter is true, then the first object is returned, otherwise the second object is returned. If the types of the two object parameters are not the same (e.g. one node-set and the other a string), then the type of the object returned is determined by rationalizing the types of the two object parameters in the same manner as XPath comparison.

Example:

choose(count(x) > 0, x, y)

Returns the node-set of matching x if it is non-empty and the node-set matching y otherwise.

2.2.5 The id() Function

node-set id(object, node-set?)

The object parameter provides one or more IDREFs. This may be in the form of a string containing a space-separated list of IDREFs or a node-set, each node of which contains an IDREF. The node-set parameter provides nodes in one or more documents to be searched. If the node-set parameter is not given or is empty, then the document to be searched is the one containing the context node of the function call. For each node in the node-set parameter (or its default), the set of element nodes are collected with IDs that match the IDREFs from the object parameter. The result of this function is a node-set containing the union of the collected element nodes from each string. An element node can be assigned an ID by means of an xml:id attribute or an attribute that is assigned the type ID by a DTD or xsd:ID by an XML schema.

Editorial note

The means of associating an ID with a node seems incomplete. Does the XForms type MIP also apply such that an element would be returned if it contains an attribute with a matching ID and the XForms type has assigned the xsd:ID type to that attribute? Perhaps more of an edge case, but what would it mean if an xsd:ID type were assigned directly to the element's content by an xsi:type attribute or a schema? Should the element be returned if it contains the matching ID? Finally, do XML schema types derived from xsd:ID count?

Example:

id('X Y', instance('Z'))

Returns nodes identified by X or Y from the XML document in the instance identified by Z.

2.2.6 The property() Function

string property(string)

This function acts as it did in XForms 1.0 except it returns "1.1" for the version.

Examples:

property("version")

returns 1.1.

property("conformance-level")

may return full.

2.2.7 Modification to Exceptions Generated by Errors in Functions

The boolean-from-string() function returns false when its string parameter does not match a case-insensitive comparison to the valid lexical values for an xsd:boolean, rather than halting processing with an xforms-compute-exception event.

When an error occurs in an XPath function, an xforms-compute-exception occurs only if the function appears in the expression of a model item property. When an error occurs in a function that appears in any other XForms attribute that contains an XPath expression, such as nodeset, ref or at, then an xforms-binding exception occurs.

2.3 Accessing Context Information for Events

node-set event(string)

Function event returns context specific information determined by the string argument. The context information is always returned as an element node with a local name equal to the parameter name and no namespace URI.

Each events will describe what properties can be accessed by this function. The following is a list of the properties accessible with the XForms 1.0 events (these are all of type xsd:string):

description: xforms-insert, xforms-delete
errorinformation: xform-submit-error, xforms-link-exception, xforms-link-error, xforms-compute-exception

Editorial note
The xforms-insert and xforms-delete events may need more information to help support decoupling of insert and delete actions from the index updating requirements of the repeat module. See 3.1 Modifications to the insert and delete Actions.

Examples:

event("description")

Returns a node with either empty content or, if called from an appropriate event handler, the context information defined for the event (e.g. the path expression used for insert/delete).

event("errorinformation")

If called from an appropriate event handler, the returned node contains the context information (e.g. the URI that failed to load for an xforms-link-exception). The returned node content is empty if there is no context information for the event.

2.4 New Data Type: Email address

XForms provides support for several built-in datatypes, includes datatypes derived by restriction, derived by list, and derived by union from these base types. XForms also defines new derived datatypes that are commonly used in forms. The following text describes a new derived datatype, xforms:email, introduced for XForms 1.1. This datatype represents an email address, as defined by [RFC 2822]. Internationalized email addresses are not restricted by XForms beyond the definition in the RFC. For simplicity, some extremely uncommon features of the RFC syntax are not allowed, such as "Obsolete Addressing" from section 4.4, square-bracketed "domain-literal"s, and insignificant whitespace and comments.

Examples of valid xforms:email addresses

editors@example.com
~my_mail+{nospam}$?@sub-domain.example.info

Examples of invalid xforms:email addresses

editors@(this is a comment)example.info
editors{at}example{dot}info

Note:

It is outside the scope of XForms to determine whether a given email address actually corresponds to an active mailbox.

Note:

To be added to the Schema for XForms 1.1--the following datatype:

<xsd:simpleType name="email">

  <xsd:restriction base="xsd:string">

    <xsd:pattern value="[A-Za-z0-9!#-'\*\+\-/=\?\^_`\{-~]+(\.[A-Za-z0-9!#-'\*\+\-/=\?\^_`\{-~
]+)*@[A-Za-z0-9!#-'\*\+\-/=\?\^_`\{-~]+(\.[A-Za-z0-9!#-'\*\+\-/=\?\^_`\{-~]+)*"/>

  </xsd:restriction>

</xsd:simpleType>

The following text is only for discussion in the Working Group, and will be removed before first publication of this document. Since regular expressions aren't a programming language, there's no way to define a common recurring segment, and the regular expression tends to get a little repetitive. Taken one step at a time, however, it makes perfect sense.

The main achievement in this lengthy statement is the definition of what the email address specification calls "atext", which is defined alpha characters, digits, or one of the following characters: "!" "#" "$" "%" "&" "'" "*" "+" "-" "/" "=" "?" "^" "_" "`" "{" "|" "}" "~" In regular expression syntax, the definition for a single character of atext looks like this: [A-Za-z0-9!#-'\*\+\-/=\?\^_`\{-~] . If regular expressions had a way to define a commonly-recurring string, the regular expression might look like this (with spaces added for readability): atext+ (\. atext+)* @ atext+ (\. atext+)* But alas, the actual regular expression needs to repeat the full definition of atext four times, yielding the full definition of the email datatype.

2.5 New Data Type: ID Card Number

This type defines the basic structure of an ID number that conforms to [ISO 7812-1:2000]. Various ID cards use this standard as the format for their numbers including those issued by Financial Institutions for Debit and Credit cards. The ID number is a pattern restriction on xsd:string: it must be between 12 and 19 digits (0 - 9).

Example: xforms:ID-card-number type definition

:<xsd:simpleType name="ID-card-number">
    <xsd:annotation>
      <xsd:documentation>
        This type defines an ID number that conforms to ISO/IEC 7812-1:2000  
		Identification cards -- Identification of issuers -- Part 1: Numbering system. 
		This type does not apply the Luhn checksum algorithm.
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:minLength value="12"/>
      <xsd:maxLength value="19"/>
      <xsd:pattern value="[0-9]+"/>
    </xsd:restriction>
  </xsd:simpleType>

The standard defines the structure of the number as well as how to apply the Luhn formula to ensure a correct check digit. This type only specifies the format of the number. The complementary XPath function luhn() should be used to validate that the ID number conforms to the specification.

Example: Credit Card Example

<xforms:model>
  <xforms:instance>
    <payment method="cc" xmlns="http://commerce.example.com/payment">
      <number/>
      <expiry/>
    </payment>
  </xforms:instance>
  <xforms:bind nodeset="number" type="xforms:ID-card-number" constraint="luhn(.)"/>
</xforms:model>

This example specifies that the element number is of the type ID-card-number and that to be valid the luhn function must evaluate to true indicating that check digit is valid.

2.6 XForms Datatypes to Allow Empty Content

Many default XML schema types report empty content as invalid. The following XForms datatypes are defined to allow either empty content or the content allowed by the corresponding XML schema datatype. XForms Processors must treat the datatypes listed in the section as in-scope without requiring the inclusion of an XML Schema.

Built-in primitive types:

xforms:dateTime
xforms:time
xforms:date
xforms:gYearMonth
xforms:gYear
xforms:gMonthDay
xforms:gDay
xforms:gMonth
xforms:string
xforms:boolean
xforms:base64Binary
xforms:hexBinary
xforms:float
xforms:decimal
xforms:double
xforms:anyURI
xforms:QName

Built-in derived types:

normalizedString
token
language
Name
NCName
ID
IDREF
IDREFS
NMTOKEN
NMTOKENS
xforms:integer
xforms:nonPositiveInteger
xforms:negativeInteger
xforms:long
xforms:int
xforms:short
xforms:byte
xforms:nonNegativeInteger
xforms:unsignedLong
xforms:unsignedInt
xforms:unsignedShort
xforms:unsignedByte
xforms:positiveInteger

Note:

Some of the corresponding XML schema datatypes do allow empty content, but the matching XForms datatypes are defined anyway for convenience so that form authors can uniformly use the XForms-defined datatypes.

3 Actions

3.1 Modifications to the `insert` and `delete` Actions

XForms 1.1 enhances the insert and delete actions so that they are more generally applicable to instance node duplication and destruction, and so that they can be used more effectively with an homogeneous collection that become empty.

3.1.1 The `insert` Action

The insert action is used to create a new node of instance data by cloning an existing instance node. Attributes of action insert specify the node to be cloned and the location within instance data where the clone will appear. The clone is a deep copy of the original node except the contents of nodes of type xsd:ID are modified to remain as unique values in the instance data after the clone is inserted.

Common Attributes: Common (optional), Events (optional), Node Set Binding (required)

Special Attributes:

context

Optional XPath expression used to override the in-scope evaluation context for the insert element. If the attribute is not given, then the default insert context is the in-scope evaluation context. Otherwise, the XPath expression is evaluated using the in-scope evaluation context, and the first node rule is applied to obtain the insert context. The insert action is terminated with no effect if the insert context is the empty node-set or if the context attribute is not given and the Node Set Binding node-set is empty.

origin

Optional XPath expression indicating the node to be cloned. If the attribute is not given and the Node Set Binding node-set is empty, then the insert action is terminated with no effect. Otherwise, if this attribute is not given, then the last node of the Node Set Binding node-set is cloned. If the attribute is given, it is evaluated in the insert context using the first node rule. If the result is a node, then it is cloned, and otherwise the insert action is terminated with no effect.

at

Optional XPath expression evaluated to determine the insert location within the Node Set Binding node-set. If the Node Set Binding node-set empty, then this attribute is ignored. If the attribute is not given, then the default is the size of the Node Set Binding node-set. Otherwise, the insert location is determined from this attribute as follows:

The evaluation context node is the first node in document order from the Node Set Binding node-set, the context size is the size of the Node Set Binding node-set, and the context position is 1.
The return value is processed according to the rules of the XPath function round(). For example, the literal 1.5 becomes 2, and the literal 'string' becomes NaN.
If the result is in the range 1 to the Node Set Binding node-set size, then the insert location is equal to the result. If the result is non-positive, then the insert location is 1. Otherwise, the result is NaN or exceeds the Node Set Binding node-set size, so the insert location is the Node Set Binding node-set size.

The insert location node is the node in the Node Set Binding node-set at the position given by the insert location.

position

Optional selector that indicates where to put the cloned node relative to the insert location. Valid values are before and after, and the latter is the default. This attribute is ignored if the Node Set Binding node-set is empty. If the node at the insert location within the Node Set Binding node-set is the document element of an instance, then this attribute is ignored.

Provided the insert action has not been terminated due to the conditions stated above, the processing rules for the insert action are as follows:

The target location of the insertion for the cloned node is determined as follows:
1. If the Node Set Binding node-set is empty, then the target location is before the first child or attribute of the insert context node, based on the node type of the cloned node.
2. If the node type of the cloned node does not match the node type of the insert location node, then the target location is before the first child or attribute of the insert location node node, based on the node type of the cloned node.
3. If the Node Set Binding node-set and insert location indicate the root element of an instance, then that instance root element location is the target location.
4. Otherwise, the target location is immediately before or after the insert location node, based on the position attribute setting or its default.
The cloned node is inserted at the target location. If the target location was the root element of an instance, then the cloned node replaces the instance root element. If the cloned node is a duplicate of another attribute in its parent element, then the duplicate attribute is removed. If the cloned node cannot be placed at the target location due to a node type conflict, then the insert action is terminated with no effect.
The index for any repeat that is bound to a homogeneous collection where the cloned node was added is updated to point to the newly inserted node, and the index of any repeat nested within an updated repeat is re-initialized to the startindex of the nested repeat.
The XForms action system's deferred update flags for rebuild, recalculate, revalidate and refresh are set.
The insert action is successfully completed by dispatching the xforms-insert event.

Editorial note
The working group is discussing how `origin` and `context` might be able to IDREF a `bind` nodeset. This may be possible by interpreting non-nodeset result as an IDREF (with `xforms-binding-exception` on failure).

Editorial note

The working group is discussing modularization of the XForms model and actions such as insert, which would require decoupling repeat index updating. One way this may be achieved is by having the repeat module set up a listener on the model for the capture phase of xforms-insert to do the updating. The event context would have to carry a pointer to the inserted node so that the each repeat's listener could determine whether the insertion is applicable to it.

Example: Inserting the clone of a prototypical element (append child, prepend child)

...
<xforms:instance id="people">
  <people xmlns=""/>
</xforms:instance>
<xforms:instance id="personProto">
  <person xmlns="">
      <name>Jane Q. Public</name>
  </person>
</xforms:instance>
...
<xforms:trigger>
  <xforms:label>Append new person</xforms:label>
  <xforms:insert context="instance('people')" nodeset="person" origin="instance('personProto')" ev:event="DOMActivate"/>
</xforms:trigger>

<xforms:trigger>
  <xforms:label>Prepend new person</xforms:label>
  <xforms:insert context="instance('people')" nodeset="person" origin="instance('personProto')" 
                 at="1" position="before" ev:event="DOMActivate"/>
</xforms:trigger>
...

Note:

Generalized append/prepend child can be done with nodeset="*" for elements and nodeset="@*" for attributes.

Example: Replacing an instance

...
<xforms:instance id="people">
  <people xmlns="">
    <person>
      <name>Jane Q. Public</name>
    </person>
    <person>
      <name>John Hancock</name>
    </person>
  </people>
</xforms:instance>
...
<xforms:instance id="peopleProto">
  <people xmlns=""/>
</xforms:instance>
...
<trigger>
  <label>Clear Person List</label>
  <insert context="instance('people')" nodeset="." origin="instance('peopleProto')" ev:event="DOMActivate"/>
</trigger>
...

Example: Duplicating a node

<insert nodeset="some/node"/>

Example: Copying an attribute

<xforms:instance xmlns="">
   <data>
      <item show="true">...</item>
      <item>...</item>
      <item willbesecondattr="true" show="false">...</item>
      <item willbesecondattr="false" show="false">...</item>
   </data>
</xforms:instance>
...
<insert nodeset="item[2]" origin="item[1]/@show"/>
<insert nodeset="item[3]" origin="item[1]/@show"/>
<insert nodeset="item[4]/@show" origin="item[1]/@show"/>
...

After the insert actions, all item elements have attribute show="true", and it will be the first attribute except for the last item. The existing show attribute is removed from the third and fourth item, but in the third item the location of the new attribute is at the beginning due to node type mismatch, and in the fourth item the location of the new attribute after (due to position default) the existing show attribute.

Example: Inserting into a repeat, whether or not it is empty

When the repeat is empty, the at index is zero so a new item is prepended. When the repeat is non-empty, the new item is added after the node currently indexed by repeat R.

...
<xforms:instance xmlns="">
   <purchaseOrder>
        <subtotal/>
        <tax/>
        <total/>
   </purchaseOrder>
</xforms:instance>
<xforms:instance xmlns="" id="prototypes">
    <prototypes>
       ...
       <item>
           <product/>
           <quantity/>
           <unitcost/>
           <price/>
       </item>
    </prototypes>
</xforms:instance>
...
<repeat nodeset="/purchaseOrder/item">
   ...
</repeat>
...
<xforms:trigger>
  <xforms:label>Add to purchase order</xforms:label>
  <xforms:action ev:event="DOMActivate>
    <xforms:insert context="/purchaseOrder" nodeset="item" at="index('R')" origin="instance('prototypes')/item"/>
    <xforms:setfocus control="R"/>
  </xforms:action>
</xforms:trigger>

3.1.2 The `delete` Action

This action deletes a node from instance data.

Common Attributes: Common (optional), Events (optional), Node Set Binding (required)

Special Attributes:

context

Optional XPath expression used to override the in-scope evaluation context for the delete element. If the attribute is not given, then the default delete context is the in-scope evaluation context. Otherwise, the XPath expression is evaluated using the in-scope evaluation context, and the first node rule is applied to obtain the delete context. The delete action is terminated with no effect if the delete context is the empty node-set or if the context attribute is not given and the Node Set Binding node-set is empty.

at

Optional XPath expression evaluated to determine the delete location within the Node Set Binding node-set. If the Node Set Binding node-set empty, then this attribute is ignored. If the attribute is not given, then the default is the size of the Node Set Binding node-set. Otherwise, the delete location is determined from this attribute as follows:

The evaluation context node is the first node in document order from the Node Set Binding node-set, the context size is the size of the Node Set Binding node-set, and the context position is 1.
The return value is processed according to the rules of the XPath function round(). For example, the literal 1.5 becomes 2, and the literal 'string' becomes NaN.
If the result is in the range 1 to the Node Set Binding node-set size, then the delete location is equal to the result. If the result is non-positive, then the delete location is 1. Otherwise, the result is NaN or exceeds the Node Set Binding node-set size, so the delete location is the Node Set Binding node-set size.

Provided the insert action has not been terminated due to the conditions stated above, the rules for delete processing are as follows:

The node at the delete location in the Node Set Binding node-set is deleted, except if the node is the root document element of an instance then the delete action is terminated with no effect.
The index for any repeat that is bound to a homogeneous collection that contained the deleted node is not changed except:
1. When the last remaining item in the collection is removed, the index position becomes 0.
2. When the index was pointing to the deleted node, which was the last item in the collection, the index is changed to point to the new last node of the collection and the indexes of inner repeats are reinitialized.
3. When the index was pointing to the deleted node, which was not the last item in the collection, the index position is not changed but the indexes of inner repeats are re-initialized.
To re-initialize a repeat index means to set it to the startindex value.
The XForms action system's deferred update flags for rebuild, recalculate, revalidate and refresh are set.
The delete action is successfully completed by dispatching the event xforms-delete.

Example: Deleting from a repeat

In this example, the trigger is not in the repeat. When it is activated, the indexed item in the repeat is first deleted. Next, if that was the last item, then a new prototypical item is inserted so that the repeat does not become empty. The focus is then sent back to the repeat from the trigger.

...
<xforms:trigger>
  <xforms:label>Delete from purchase order</xforms:label>
  <xforms:action ev:event="DOMActivate>
    <xforms:delete context="/purchaseOrder" nodeset="item" at="index('R')"/>
    <xforms:insert if="not(/purchaseOrder/item)"
                   context="/purchaseOrder" nodeset="item" origin="instance('prototypes')/item"/>
    <xforms:setfocus control="R"/>
  </xforms:action>
</xforms:trigger>

Note:

The form author could have written nodeset="/purchaseOrder/item", but the context attribute was added for consistency with the insert action.

Editorial note
Further to the point of consistency, it seems prudent to consider adding `context` to the Node Set Binding attribute bundle so it can be consumed by not just `insert` and `delete` but also `repeat` (and `itemset`). Aside from consistency, this might also help with formulating a reasonable relaxation of the definition of homogeneous collection.

Editorial note
The working group is discussing how `context` might be able to IDREF a `bind` nodeset. This may be possible by interpreting non-nodeset result as an IDREF (with `xforms-binding-exception` on failure).

Editorial note

The working group is discussing modularization of the XForms model and actions such as delete, which would require decoupling repeat index updating. One way this may be achieved is by having the repeat module set up a listener on the model for the capture phase of xforms-delete to do the updating. The event context would have to carry a pointer to the delete context node, the parent of the deleted node, and the orphaned deleted node so that each repeat's listener could determine whether the deletion is applicable to it.

3.2 The `close` Action Element

This action is used to dispatch an xforms-close event to a model.

Common attributes: Common, Events

Special attributes: None

Dispatches an xforms-close event to the default model.

Example: Closing a document

<trigger>
  <label>Close</label>
  <close ev:event="DOMActivate"/>
</trigger>

3.2.1 The `xforms-close` Event

This event, dispatched to the default model element, results in closing down the owner document. In a rendering environment, this may close down the user agent that renders the document.

Target: model
Bubbles: Yes
Cancelable: Yes
Context Info:: None.

The default action for this event results in the following: Close down the owner document.

3.3 The `prompt` Action Element

This action provides a prompt and a modal method for the user to respond by activating a trigger. If XForms actions are associated with the DOMActivate of the trigger activated by the user, then those actions are performed. When a DOMActivate event bubbles up to the prompt element from any of its child trigger controls, this action releases the modal prompt and stops the propagation of the event. More generally, this action stops the propagation in the bubble phase of any events that reaches the prompt element.

Common attributes: Common, Events

Special attributes: None

Content: label, trigger+

Example: Getting confirmation to proceed with a submission

        <trigger>
          <label>Submit Personal Business Commitments</label>
          <prompt ev:event="DOMActivate">
              <label>You will not be able to modify your PBC's again unless your manager 
                          returns them to you.  Are you sure you want to submit?</label>
              <trigger>
                  <label>Yes</label>
                  <send ev:event="DOMActivate" submission="X"/>
              </trigger>
              <trigger>
                  <label>No</label>
              </trigger>
          </prompt>
        </trigger>

Note:

Actions performed in response to activation of a trigger in a prompt are subject to normal deferred update behavior (i.e. rebuild, recalculate, revalidate, refresh do not occur until after the prompt, or later if the prompt is part of an even larger action sequence).

3.4 Conditional Execution of XForms Actions

The if attribute can be added to any XForms action. It contains an [XPath 1.0] expression that is evaluated using the in-scope evaluation context before the action is executed. The result of the expression is converted to a boolean as if converted with the boolean() function defined by the [XPath 1.0] specification. If the converted result of the expression evaluates to false, then the action is not performed. If the converted result is true, then the action is performed.

If this attribute is applied to an XForms action element and the converted result of evaluation is false, then all of the actions within the action element are omitted from the execution of the XForms action sequence that invoked the action element. If the result is true, then the contained actions are performed according to the normal processing rules such as deferred update behavior and applicability of conditional and iterative attributes.

Example: Automatic Focus Advancement

The setfocus action in each input control is executed only if the node bound to the control is a number of a particular length. The exacting form author could perform further validity tests.

...
<input ref="areaCode" id="AreaCodeControl" incremental="true">
	<label>Area Code</label>
	<setfocus ev:event="xforms-value-changed" control="ExchangeControl" if="string-length(.)=3 and . > 0"/>
</input>
<input ref="exchange" id="ExchangeControl" incremental="true">
	<label>Exchange</label>
	<setfocus ev:event="xforms-value-changed" control="LocalControl" if="string-length(.)=3 and . > 0"/>
</input>
<input ref="local" id="LocalControl" incremental="true">
	<label>Local</label>
	<setfocus ev:event="xforms-value-changed" control="ExtensionControl" if="string-length(.)=4 and . > 0"/>
</input>
...

Example: Handling Focus for Empty Repeats

The trigger that performs a delete conditionally sets the focus to a control outside of the repeat if the repeat becomes empty due to the deletion. The setfocus is called first because the delete removes the context node.

...
<trigger id="InsertControl">
	<label>Insert Row</label>
	<action ev:event="DOMActivate">
		<insert context="purchaseOrder/lines" nodeset="line" 
				at="index('PurchaseOrderRepeat')" origin="instance('prototype')"/>
		<setfocus control="PurchaseOrderRepeat"/>
	</action>
</trigger>
<repeat nodeset="purchaseOrder/lines/line" id="PurchaseOrderRepeat">
	...
	<trigger>
	  <label>Delete Row</label>
		  <action ev:event="DOMActivate">
			  <setfocus control="lnsertControl" if="last()=1"/>
			  <delete  nodeset="../line" at="index('PurchaseOrderRepeat')"/>
		  </action>
	</input>
	...
</repeat>

3.5 Iteration of XForms Actions

The while attribute can be added to any XForms action. It contains an [XPath 1.0] expression that is evaluated using the in-scope evaluation context before the action is executed. The result of the expression is converted to a boolean as if converted with the boolean() function defined by the [XPath 1.0] specification. If the converted result of the expression is true, then the XForms action is performed and then the expression is re-evaluated. The XForms action is iterated repeatedly until the converted result of the expression evaluates to false.

If this attribute is applied to an XForms action element, then the sequence of XForms actions in its content are executed repeatedly once for each time the immediately preceding evaluation of the expression yields a result of true.

When XForms actions are iteratively executed, they are still subject to the normal action processing rules such as deferred update and applicability of conditional and iterative attributes.

If an action bears this attribute and the if attribute, then the expressions of both attributes must evaluate to true before each iterative execution of the action.

Example: Summing Selected Results

Counter and Accumlator Variables are Created in Instance Data to Sum a Selection of Values Chosen by the User

<trigger>
	<label>Get Sum</label>
	<action ev:event="DOMActivate">
		<setvalue ref="instance('temps')/counter" value="1"/>
		<setvalue ref="instance('temps')/accumulator" value="0"/>
		<action while="instance('temps')/counter &lt;= count(/some/nodes)">
			<setvalue ref="instance('temps')/accumulator" 
				value=". + /some/nodes[instance('temps')/counter]"
				if="boolean-from-string(/some/nodes[instance('temps')/counter]/@selected)"/>
			<setvalue ref="instance('temps')/counter" value=". + 1"/>
		</action>
	</action>
</trigger>

3.6 Modifications to Deferred Update Behavior of Actions

TBD

In XForms 1.0, the deferred update behavior would choose to run rebuild, recalculate, revalidate and refresh actions directly, bypassing the event system. In XForms 1.1, the events are dispatched as needed.

The detection of the need for deferred update is managed at the level of the XForms model. When XForms action B runs as the result of another XForms action A, then the deferred update behavior of B is further deferred to the completion of A, regardless of whether B is a descendant of A in the XML markup.

4 Submission

4.1 New Submission Events

4.1.1 The xforms-submit-serialize Event

Dispatched by the processor immediately before serializing the instance data for submission (immediately before step 3, Section 11.1, XForms 1.0).

Target: submission

Bubbles: Yes

Cancelable: No

Context Info: A node into which data to be submitted can be placed.

The default action for this event is to perform the normal XForms submission serialization if the event context node's content is empty. The content of the event context node is the data sent by the XForms submission.

4.2 New Submission Attributes

4.2.1 The validate attribute on element submission

The submission element must allow a new optional attribute named validate of type boolean. The default value is true.

If the value of attribute validate is true then the processing of a submission is unchanged from XForms 1.0, i.e. the instance being submitted must be valid for processing to proceed.

If the value of attribute validate is false then the processing of a submission is changed from XForms 1.0 in the following way. The instance will still be validated according to the rules defined for the xforms-revalidate event but an xforms-submit-error will not be dispatched if there is a validation error allowing submission processing to proceed.

4.2.2 The relevant attribute on element submission

The submission element must allow a new optional attribute named relevant of type boolean. The default value is true.

If the value of attribute relevant is true then the processing of a submission is unchanged from XForms 1.0, i.e. the instance being submitted will not contain instance data nodes whose model item property relevant evaluates to false().

If the value of attribute validate is false then the processing of a submission is changed from XForms 1.0 in the following way. When the instance is serialized it will contain all selected instance data nodes, including instance data nodes whose model item property relevant evaluates to false().

4.3 Integration with SOAP

4.3.1 Representation of SOAP Envelope

The single-node binding of the submission element refers to the XML data to be submitted. In the case of a SOAP submission, the instance data includes the SOAP envelope and related SOAP tags.

Note:

The form author may choose to store the data payload in one instance and copy the data to the submission instance containing the SOAP envelope as part of an xforms-submit event handler. The form author is responsible for declaring the appropriate model item properties on both instances (e.g. the relevant declarations).

4.3.2 Indicating a SOAP submission

For a SOAP submission, the mediatype attribute of the submission must be set to the MIME type of application/soap+xml. The form author may append charset and action MIME parameters.

Note:

The action MIME parameter has no effect unless the submission method is "post" because the GET method implies no SOAP processing by the receiving SOAP node.

Note:

SOAP 1.1 does not support the HTTP GET operation.

4.3.3 SOAP HTTP Binding

The method attribute of the submission must be set to get or post in order to access the SOAP HTTP binding, which results in the use of the application/xml serialization rules.

If method="get", then the SOAP response message exchange pattern is used. The HTTP headers must contain the Accept parameter with a value conforming to the following properties:

must begin with application/soap+xml
If the submission mediatype contains a charset MIME parameter, then it is appended to the The application/soap+xml MIME type
No other MIME parameters from the mediatype are copied to the application/soap+xml MIME type
The q MIME parameter must not be specified in the application/soap+xml MIME type so that the default quality of 1 is used.

If method="post", then the SOAP request-response message exchange pattern is used. For SOAP 1.2, the current submission behavior of using the mediatype attribute value as the value of the ContentType parameter in the HTTP headers is sufficient. If the instance data being submitted has as its root element node a SOAP envelope in the SOAP 1.1 namespace (http://schemas.xmlsoap.org/soap/envelope/), then:

the ContentType HTTP header is change to text/xml
the charset MIME parameter is appended if it was specified in the mediatype
if the action MIME parameter appears in the mediatype then a SOAPAction HTTP header is added and given a value equal to the content of the action MIME parameter

Note:

XForms 1.1 does not support the SOAP email binding, so method="post" with a mailto: scheme results in an xforms-submit-error event before any submit processing message is dispatched.

Note:

XForms 1.1 does not support the SOAP 1.1 binding to the HTTP Extension Framework.

4.3.4 Handling the SOAP Response

The XForms processor must handle client authorization and redirection.

SOAP faults (400 and 500 level errors) are handled in the same manner as underlying HTTP errors, which is to say that an xforms-submit-error event is dispatched.

On successful completion, the results are consumed according to the XForms submission process, culminating in an xforms-submit-done event. The form author may capture this event and copy data from the target instance that receives the returned SOAP envelope to other instances that are designed to carry only data.

5 User Interface Improvements and Changes

5.1 Inline Rendition of Non-Text Media Types

In XForms 1.0, the output element can take a single node binding indicating an instance node whose textual content is to be rendered inline. In XForms 1.1, the content model of the output element is enhanced to allow the specification of a mediatype attribute or a mediatype child element.

The mediatype attribute and mediatype child element are ignored unless the output has a single node binding that resolves to an instance node with non-empty content.

When both the mediatype attribute and the mediatype element are given, the attribute takes precedence. When the mediatype element has both content and a single node binding, the single node binding takes precedence. When neither the mediatype attribute nor the mediatype element are given, the output behaves as in XForms 1.0, rendering inline the text content of an identified instance node.

The mediatype attribute or element indicates the desired type of media rendition that should be performed if it is possible to do so (e.g. a voice-only device cannot render a digital image). The desired rendition type is indicated by a string value, such as image/* or image/png, in the mediatype attribute value, the content of the node referenced by the mediatype element, or the mediatype element content.

If the mediatype attribute or element is given, then the data obtained from the instance node indicated by the single node binding must be decoded or dereferenced prior to rendition as follows:

If the instance node is of type xsd:base64Binary, then the data is base-64 decoded.
If the instance node is of type xsd:hexBinary, then the data is hex-binary decoded.
If the instance node is of type xsd:anyURI, then the data is treated as a URI and dereferenced.
If the instance node is of any other type, then the data is used without modification.

Editorial note
What of types derived from base64Binary, hexBinary and anyURI? The question for anyURI seems a bit more near-term than the one for base64Binary and hexBinary.

Example: Displaying an image uploaded to instance data

Given the following model:

<xforms:model>
	<xforms:instance xmlns="">
		<data></data>
	</xforms:instance>
	<xforms:bind nodeset="/data" type="xsd:base64Binary"/>
</xforms:model>

The following controls can upload an image to instance data and display it:

<xforms:upload ref="/data" mediatype="image/*">
	<xforms:label>Press me to attach a picture</xforms:label>
</xforms:upload>
		
<xforms:output ref="/data" mediatype="image/*"/>

The rendition of the output is updated if the referenced node or its content or if the media type changes. The media type can change due to DOM mutation of the content of the mediatype attribute or element or by a change to the mediatype element's referenced node or its content.

Failure to render the content indicated by the output element should result in an xforms-output-error, a non-fatal error that does not halt XForms processing. Failures can occur for many reasons, including

Data to be decoded does not conform to the format of xsd:base64Binary or xsd:hexBinary
An xforms-link-error dereferencing a node of type xsd:anyURI
A data format error (e.g. invalid or unsupported image format)
An unrecognized media type identifier string

5.1.1 The xforms-output-error Event

Dispatched by the processor immediately after the first failure of an output to render or update the rendition of content.

Target: output

Bubbles: Yes

Cancelable: No

Context Info: None.

The default action for this event is nothing; notification event only.

Since the output element can be the target of the xforms-output-error, the content model for the output is opened further to include XForms actions.

5.2 Add UI Common to `output`

In XForms 1.0, an output can have an optional label. In XForms 1.1, the content model for output is changed to include (UI Common)* so that help, hint, alert and XForms action elements can also appear as children of an output.

Example: Indicating an error displaying an image

<xforms:output ref="/data" mediatype="image/*">
	<xforms:message ev:event="xforms-output-error" level="ephemeral">Error in image data.</xforms:message>
</xforms:output>

Example: Providing better information on output to the user

<xforms:output ref="/purchaseOrder/Total">
	<xforms:alert>The purchase order total is too high.</xforms:alert>
	<xforms:hint>Make two or more separate orders.</xforms:hint>
</xforms:output>

5.3 Remove Linking Attributes from Actions and Metadata Elements

In order to better encapsulate and separate the behavior of an XForms processor from that of a host language processor, the src attribute is not available to XForms 1.1 message, label, help, hint, alert elements.

5.4 Appearance Hint for Triggers

XForms 1.0 defines the attribute appearance for all form controls. It is an optional attribute that provides a rendering hint to the user agent. The XForms 1.0 Recommendation provides some examples of how a user agent may interpret the appearance hint for form controls such as select1 and select. This specification provides the further example for the trigger and submit form controls that user agent processors may interpret the value "minimal" in the attribute appearance as a hint to visually render the trigger with no border, a transparent background and an underline. This rendition hint is meant to be analogous to the typical visual rendition of an XHTML anchor element.

5.5 Support `switch` in `repeat`

The content model for element repeat includes switch. For each instance data node in the Node-set Binding, the repeat element instantiates a set of run-time objects that correspond to the form controls in the repeat contextualized by the instance data node. When a switch element has one or more repeat element ancestors, then one or more rum-time switch objects are instantiated based on contextualizing the switch element with nodes from the containing repeat element(s). Similarly, a toggle element may have one or more repeat element ancestors, so a single toggle element corresponds to one or more run-time toggle objects. In this case, the indexes of the repeat element(s) that contain the switch and the toggle as well as the document location of the switch relative to the toggle are used to determine which switch object is to be manipulated by a toggle object.

The toggle action is performed by a run-time toggle object. The toggle action begins IDREF resolution by searching the document for the case element identified by the case attribute of the toggle object. If the document does not contain a case element with the matching ID, then the toggle action has no effect. Otherwise, the switch element containing the case is obtained. Then, the ancestor repeat elements of the switch element are partitioned into two subsets, those in common with the toggle element and those that are not in common. For the repeat elements that are in common, the desired switch object exists in the set of run-time objects containing the toggle object. Finally, for each ancestor repeat of the switch element that is not in common with the toggle element, the current index of the repeat determines the set of run-time objects that contains the desired switch object that is toggled.

Editorial note

The XForms 1.0 recommendation mentions that future versions of XForms may specify the behavior of switch in repeat based on implementation experience and user feedback. This has occurred in XForms 1.0 processors as they have matured, along with the observation that the IDREF problem for toggle is also applicable to other actions such as setfocus and setindex. Since XForms 1.0 does not specify the behavior of these actions when the identified element appears within a repeat, the current intent of the working group is to issue an erratum to XForms 1.0 Second Edition to allow switch in repeat as a straightforward result of specifying the general solution to the problem of referencing repeated controls by ID. Thus, XForms 1.1 would have this functionality by virtue of its availability as of XForms 1.0 Third Edition.

6 Conformance

6.1 XForms Model

The XForms model can contain or reference XML schemas, XForms instance elements, XForms bind elements, XForms submission elements, and XForms actions. XForms submission elements can also contain XForms actions.

An XForms processor should permit XForms actions to handle the following events: xforms-rebuild, xforms-recalculate, xforms-revalidate, xforms-refresh. An XForms processor must permit XForms actions to handle all other events targetted at model and submission elements. An XForms processor must support direct appearance of the event attribute (from [XML Events]) on an XForms action that is a child of the event target. An XForms processor should support the definition of XForms actions for events that bubble to the parent of the event target. An XForms processor may support all other attributes, elements and features of XML events.

The following conformance statements pertain to message actions used in events targetted at model and submission elements. An XForms processor must support presentation of the XPath string of the message content. An XForms processor should support the use of the XForms output as part of message action textual content for all model and submission events after the last xforms-model-construct default action has been performed. An XForms processor may support the inclusion of other child elements to mark up the text content of message actions.

An XForms processor may support submissions prior to the xforms-ready event and after the xforms-model-destruct event. An XForms processor must support submissions requested as of the xforms-ready event and prior to the xforms-model-destruct event. An XForms processor should support all submission methods and must support the post, get and put methods.

Except as noted above, an XForms processor must support all features of the XForms model element and its contents, including their interactions (e.g. the effects on submission of the relevant model item properties expressed by bind elements). This also includes features expressed not just by elements and attributes, but also by their content, such as the additional XPath functions and schema data types defined by XForms.

6.2 XForms User Interface

The XForms user interface elements include basic form controls such as input, trigger and select1 as well as elements for organizing and iterating other elements, such as group, switch and repeat. Other XForms user interface elements, such as label, help, hint and alert, provide additional information about the elements that contain them. There are also additional support elements such as itemset for select1 and case for switch. Finally, XForms defines several events that are targetted at certain user interface elements. These events occur at specified times in the XForms processing model as well as due to user interaction, and XForms actions can be defined to respond to these events.

An XForms processor should support all features of all XForms user interface elements, except as follows. An XForms processor may support the inclusion of child elements other than output to mark up the text content of message actions. An XForms processor may support the attributes, elements and features of XML events for events targetted at user interface elements. If any user interface events are not supported, then XForms model events that are defined in terms of the issuance of user interface events should have the same net effect on user interface elements as if the events' default actions had occurred. For example, the xforms-refresh should result in an update of the values and state of the user interface.

6.3 XForms Namespace

XForms elements may be used in the namespace declared in this specification. However, the XForms namespace is designed to be a chameleon namespace that allows XForms elements to be imported into a host language. Therefore, an XForms processor should allow parameterization of the namespace URI. Any element with a local name of an elements defined by XForms would then be recognized for XForms processing if the element's namespace URI also matched the URI parameter provided to the XForms processor.

6.4 Incompatibilities between XForms 1.0 and XForms 1.1

While many XForms 1.0 forms will operate as originally intended when migrated to an XForms 1.1 processor by simply redefining the xforms prefix to be the namespace URI of XForms 1.1, there are some behavioral changes that have been made to elements and features that existed in XForms 1.0. Therefore, some XForms 1.0 forms will require some adjustments beyond simply changing the namespace URI.

XForms 1.1

W3C Working Draft 09 December 2005

Abstract

Status of this Document

Table of Contents

Appendices

1 Introduction

1.1 Reading the Specification

1.2 How the Specification is Organized

1.3 Documentation Conventions

2 XForms Core

2.1 Namespaces for XForms 1.1

2.1.1 No-namespace schema for XForms 1.1

2.1.2 Namespaced schema for XForms 1.1

2.2 Utility Functions used in XPath Expressions

2.2.1 The power() Function

2.2.2 The luhn() Function

2.2.3 The current() Function

2.2.4 The choose() Function

2.2.5 The id() Function

2.2.6 The property() Function

2.2.7 Modification to Exceptions Generated by Errors in Functions

2.3 Accessing Context Information for Events

2.4 New Data Type: Email address

2.5 New Data Type: ID Card Number

2.6 XForms Datatypes to Allow Empty Content

3 Actions

3.1 Modifications to the insert and delete Actions

3.1.1 The insert Action

3.1.2 The delete Action

3.2 The close Action Element

3.2.1 The xforms-close Event

3.3 The prompt Action Element

3.4 Conditional Execution of XForms Actions

3.5 Iteration of XForms Actions

3.6 Modifications to Deferred Update Behavior of Actions

4 Submission

4.1 New Submission Events

4.1.1 The xforms-submit-serialize Event

4.2 New Submission Attributes

4.2.1 The validate attribute on element submission

4.2.2 The relevant attribute on element submission

4.3 Integration with SOAP

4.3.1 Representation of SOAP Envelope

4.3.2 Indicating a SOAP submission

4.3.3 SOAP HTTP Binding

4.3.4 Handling the SOAP Response

5 User Interface Improvements and Changes

5.1 Inline Rendition of Non-Text Media Types

5.1.1 The xforms-output-error Event

5.2 Add UI Common to output

5.3 Remove Linking Attributes from Actions and Metadata Elements

5.4 Appearance Hint for Triggers

5.5 Support switch in repeat

6 Conformance

6.1 XForms Model

6.2 XForms User Interface

6.3 XForms Namespace

6.4 Incompatibilities between XForms 1.0 and XForms 1.1

A Schema for XForms 1.1

B References

B.1 Normative References

B.2 Informative References

C Changes (Non-Normative)

D Acknowledgements (Non-Normative)

E Production Notes (Non-Normative)

3.1 Modifications to the `insert` and `delete` Actions

3.1.1 The `insert` Action

3.1.2 The `delete` Action

3.2 The `close` Action Element

3.2.1 The `xforms-close` Event

3.3 The `prompt` Action Element

5.2 Add UI Common to `output`

5.5 Support `switch` in `repeat`