4.10.6 The label element

Categories:
Flow content.
Phrasing content.
Interactive content.
Form-associated element.
Palpable content.
Contexts in which this element can be used:
Where phrasing content is expected.
Content model:
Phrasing content, but with no descendant labelable elements unless it is the element's labeled control, and no descendant label elements.
Content attributes:
Global attributes
form
for
DOM interface:
interface HTMLLabelElement : HTMLElement {
  readonly attribute HTMLFormElement? form;
           attribute DOMString htmlFor;
  readonly attribute HTMLElement? control;
};

The label represents a caption in a user interface. The caption can be associated with a specific form control, known as the label element's labeled control, either using for attribute, or by putting the form control inside the label element itself.

Except where otherwise specified by the following rules, a label element has no labeled control.

The for attribute may be specified to indicate a form control with which the caption is to be associated. If the attribute is specified, the attribute's value must be the ID of a labelable element in the same Document as the label element. If the attribute is specified and there is an element in the Document whose ID is equal to the value of the for attribute, and the first such element is a labelable element, then that element is the label element's labeled control.

If the for attribute is not specified, but the label element has a labelable element descendant, then the first such descendant in tree order is the label element's labeled control.

The label element's exact default presentation and behavior, in particular what its activation behavior might be, if anything, should match the platform's label behavior. The activation behavior of a label element for events targetted at interactive content descendants of a label element, and any descendants of those interactive content descendants, must be to do nothing.

For example, on platforms where clicking a checkbox label checks the checkbox, clicking the label in the following snippet could trigger the user agent to run synthetic click activation steps on the input element, as if the element itself had been triggered by the user:

<label><input type=checkbox name=lost> Lost</label>

On other platforms, the behavior might be just to focus the control, or do nothing.

The form attribute is used to explicitly associate the label element with its form owner.

The following example shows three form controls each with a label, two of which have small text showing the right format for users to use.

<p><label>Full name: <input name=fn> <small>Format: First Last</small></label></p>
<p><label>Age: <input name=age type=number min=0></label></p>
<p><label>Post code: <input name=pc> <small>Format: AB12 3CD</small></label></p>
label . control

Returns the form control that is associated with this element.

The htmlFor IDL attribute must reflect the for content attribute.

The control IDL attribute must return the label element's labeled control, if any, or null if there isn't one.

The form IDL attribute is part of the element's forms API.

control . labels

Returns a NodeList of all the label elements that the form control is associated with.

Labelable elements have a NodeList object associated with them that represents the list of label elements, in tree order, whose labeled control is the element in question. The labels IDL attribute of labelable elements, on getting, must return that NodeList object.