HTML

Living Standard — Last Updated 7 March 2021

1. 1. 4.11 Interactive elements
      1. 4.11.1 The details element
      2. 4.11.2 The summary element
      3. 4.11.3 Commands
         1. 4.11.3.1 Facets
         2. 4.11.3.2 Using the a element to define a command
         3. 4.11.3.3 Using the button element to define a command
         4. 4.11.3.4 Using the input element to define a command
         5. 4.11.3.5 Using the option element to define a command
         6. 4.11.3.6 Using the accesskey attribute on a legend element to define a command
         7. 4.11.3.7 Using the accesskey attribute to define a command on other elements
      4. 4.11.4 The dialog element

4.11 Interactive elements

4.11.1 The details element

Categories :

Flow content .

Sectioning root .

Interactive content .

Palpable content .

Contexts in which this element can be used :

Where flow content is expected.

Content model :

One summary element followed by flow content .

Content attributes :

Global attributes

open

Accessibility considerations :

For authors .

For implementers .

DOM interface :

[Exposed=Window]
interface HTMLDetailsElement : HTMLElement {
  [HTMLConstructor] constructor();
  [CEReactions] attribute boolean open;
};

The details element represents a disclosure widget from which the user can obtain additional information or controls.

The details element is not appropriate for footnotes. Please see the section on footnotes for details on how to mark up footnotes.

The first summary element child of the element, if any, represents the summary or legend of the details. If there is no child summary element, the user agent should provide its own legend (e.g. "Details").

The rest of the element's contents represents the additional information or controls.

The open content attribute is a boolean attribute . If present, it indicates that both the summary and the additional information is to be shown to the user. If the attribute is absent, only the summary is to be shown.

When the element is created, if the attribute is absent, the additional information should be hidden; if the attribute is present, that information should be shown. Subsequently, if the attribute is removed, then the information should be hidden; if the attribute is added, the information should be shown.

The user agent should allow the user to request that the additional information be shown or hidden. To honor a request for the details to be shown, the user agent must set the open attribute on the element to the empty string. To honor a request for the information to be hidden, the user agent must remove the open attribute from the element.

This ability to request that additional information be shown or hidden may simply be the activation behavior of the appropriate summary element, in the case such an element exists. However, if no such element exists, user agents can still provide this ability through some other user interface affordance.

Whenever the open attribute is added to or removed from a details element, the user agent must queue an element task on the DOM manipulation task source given then details element that runs the following steps, which are known as the details notification task steps , for this details element:

1. If another task has been queued to run the details notification task steps for this details element, then return.

   When the open attribute is toggled several times in succession, these steps essentially get coalesced so that only one event is fired.

2. Fire an event named toggle at the details element.

The open IDL attribute must reflect the open content attribute.

<section class="progress window">
 <h1>Copying "Really Achieving Your Childhood Dreams"</h1>
 <details>
  <summary>Copying... <progress max="375505392" value="97543282"></progress> 25%</summary>
  <dl>
   <dt>Transfer rate:</dt> <dd>452KB/s</dd>
   <dt>Local filename:</dt> <dd>/home/rpausch/raycd.m4v</dd>
   <dt>Remote filename:</dt> <dd>/var/www/lectures/raycd.m4v</dd>
   <dt>Duration:</dt> <dd>01:16:27</dd>
   <dt>Color profile:</dt> <dd>SD (6-1-6)</dd>
   <dt>Dimensions:</dt> <dd>320×240</dd>
  </dl>
 </details>
</section>

<details>
 <summary><label for=fn>Name & Extension:</label></summary>
 <p><input type=text id=fn name=fn value="Pillar Magazine.pdf">
 <p><label><input type=checkbox name=ext checked> Hide extension</label>
</details>

<style>
 details > summary { transition: color 1s; color: black; }
 details[open] > summary { color: red; }
</style>
<details>
 <summary>Automated Status: Operational</summary>
 <p>Velocity: 12m/s</p>
 <p>Direction: North</p>
</details>

4.11.2 The summary element

Categories :

None.

Contexts in which this element can be used :

As the first child of a details element.

Content model :

Phrasing content , optionally intermixed with heading content .

Content attributes :

Global attributes

Accessibility considerations :

For authors .

For implementers .

DOM interface :

Uses HTMLElement .

The summary element represents a summary, caption, or legend for the rest of the contents of the summary element's parent details element, if any.

A summary element is a summary for its parent details if the following algorithm returns true:

1. If this summary element has no parent, then return false.

2. Let parent be this summary element's parent.

3. If parent is not a details element, then return false.

4. If parent 's first summary element child is not this summary element, then return false.

5. Return true.

The activation behavior of summary elements is to run the following steps:

1. If this summary element is not the summary for its parent details , then return.

2. Let parent be this summary element's parent.

3. If the open attribute is present on parent , then remove it. Otherwise, set parent 's open attribute to the empty string.

   This will then run the details notification task steps .

4.11.3 Commands

4.11.3.1 Facets

A command is the abstraction behind menu items, buttons, and links. Once a command is defined, other parts of the interface can refer to the same command, allowing many access points to a single feature to share facets such as the Disabled State .

Commands are defined to have the following facets :

Label

The name of the command as seen by the user.

Access Key

A key combination selected by the user agent that triggers the command. A command might not have an Access Key.

Hidden State

Whether the command is hidden or not (basically, whether it should be shown in menus).

Disabled State

Whether the command is relevant and can be triggered or not.

Action

The actual effect that triggering the command will have. This could be a scripted event handler, a URL to which to navigate , or a form submission.

User agents may expose the commands that match the following criteria:

• The Hidden State facet is false (visible)
• The element is in a document with a non-null browsing context .
• Neither the element nor any of its ancestors has a hidden attribute specified.

User agents are encouraged to do this especially for commands that have Access Keys , as a way to advertise those keys to the user.

For example, such commands could be listed in the user agent's menu bar.

4.11.3.2 Using the a element to define a command

An a element with an href attribute defines a command .

The Label of the command is the element's descendant text content .

The Access Key of the command is the element's assigned access key , if any.

The Hidden State of the command is true (hidden) if the element has a hidden attribute, and false otherwise.

The Disabled State facet of the command is true if the element or one of its ancestors is inert , and false otherwise.

The Action of the command is to fire a click event at the element.

4.11.3.3 Using the button element to define a command

A button element always defines a command .

The Label , Access Key , Hidden State , and Action facets of the command are determined as for a elements (see the previous section).

The Disabled State of the command is true if the element or one of its ancestors is inert , or if the element's disabled state is set, and false otherwise.

4.11.3.4 Using the input element to define a command

An input element whose type attribute is in one of the Submit Button , Reset Button , Image Button , Button , Radio Button , or Checkbox states defines a command .

The Label of the command is determined as follows:

• If the type attribute is in one of the Submit Button , Reset Button , Image Button , or Button states, then the Label is the string given by the value attribute, if any, and a UA-dependent, locale-dependent value that the UA uses to label the button itself if the attribute is absent.

• Otherwise, if the element is a labeled control , then the Label is the descendant text content of the first label element in tree order whose labeled control is the element in question. (In JavaScript terms, this is given by element .labels[0].textContent .)

• Otherwise, if the value attribute is present, then the Label is the value of that attribute.

• Otherwise, the Label is the empty string.

The Access Key of the command is the element's assigned access key , if any.

The Hidden State of the command is true (hidden) if the element has a hidden attribute, and false otherwise.

The Disabled State of the command is true if the element or one of its ancestors is inert , or if the element's disabled state is set, and false otherwise.

The Action of the command is to fire a click event at the element.

4.11.3.5 Using the option element to define a command

An option element with an ancestor select element and either no value attribute or a value attribute that is not the empty string defines a command .

The Label of the command is the value of the option element's label attribute, if there is one, or else the option element's descendant text content , with ASCII whitespace stripped and collapsed .

The Access Key of the command is the element's assigned access key , if any.

The Hidden State of the command is true (hidden) if the element has a hidden attribute, and false otherwise.

The Disabled State of the command is true if the element is disabled , or if its nearest ancestor select element is disabled , or if it or one of its ancestors is inert , and false otherwise.

If the option 's nearest ancestor select element has a multiple attribute, the Action of the command is to toggle the option element. Otherwise, the Action is to pick the option element.

4.11.3.6 Using the accesskey attribute on a legend element to define a command

A legend element defines a command if all of the following are true:

• It has an assigned access key .

• It is a child of a fieldset element.

• Its parent has a descendant that defines a command that is neither a label element nor a legend element. This element, if it exists, is the legend element's accesskey delegatee .

The Label of the command is the element's descendant text content .

The Access Key of the command is the element's assigned access key .

The Hidden State , Disabled State , and Action facets of the command are the same as the respective facets of the legend element's accesskey delegatee .

<fieldset>
 <legend accesskey=p>
  <label>I want <input name=pizza type=number step=1 value=1 min=0>
   pizza(s) with these toppings</label>
 </legend>
 <label><input name=pizza-cheese type=checkbox checked> Cheese</label>
 <label><input name=pizza-ham type=checkbox checked> Ham</label>
 <label><input name=pizza-pineapple type=checkbox> Pineapple</label>
</fieldset>

4.11.3.7 Using the accesskey attribute to define a command on other elements

An element that has an assigned access key defines a command .

If one of the earlier sections that define elements that define commands define that this element defines a command , then that section applies to this element, and this section does not. Otherwise, this section applies to that element.

The Label of the command depends on the element. If the element is a labeled control , the descendant text content of the first label element in tree order whose labeled control is the element in question is the Label (in JavaScript terms, this is given by element .labels[0].textContent ). Otherwise, the Label is the element's descendant text content .

The Access Key of the command is the element's assigned access key .

The Hidden State of the command is true (hidden) if the element has a hidden attribute, and false otherwise.

The Disabled State of the command is true if the element or one of its ancestors is inert , and false otherwise.

The Action of the command is to run the following steps:

1. Run the focusing steps for the element.
2. Fire a click event at the element.

4.11.4 The dialog element

Categories :

Flow content .

Sectioning root .

Contexts in which this element can be used :

Where flow content is expected.

Content model :

Flow content .

Content attributes :

Global attributes

open

Accessibility considerations :

For authors .

For implementers .

DOM interface :

[Exposed=Window]
interface HTMLDialogElement : HTMLElement {
  [HTMLConstructor] constructor();
  [CEReactions] attribute boolean open;
  attribute DOMString returnValue;
  [CEReactions] undefined show();
  [CEReactions] undefined showModal();
  [CEReactions] undefined close(optional DOMString returnValue);
};

The dialog element represents a part of an application that a user interacts with to perform a task, for example a dialog box, inspector, or window.

The open attribute is a boolean attribute . When specified, it indicates that the dialog element is active and that the user can interact with it.

A dialog element without an open attribute specified should not be shown to the user. This requirement may be implemented indirectly through the style layer. For example, user agents that support the suggested default rendering implement this requirement using the CSS rules described in the rendering section .

The tabindex attribute must not be specified on dialog elements.

dialog . show ()

Displays the dialog element.

dialog . showModal ()

Displays the dialog element and makes it the top-most modal dialog.

This method honors the autofocus attribute.

dialog . close ( [ result ] )

Closes the dialog element.

The argument, if provided, provides a return value.

dialog . returnValue [ = result ]

Returns the dialog 's return value.

Can be set, to update the return value.

When the show() method is invoked, the user agent must run the following steps:

1. If the element already has an open attribute, then return.

2. Add an open attribute to the dialog element, whose value is the empty string.

3. Run the dialog focusing steps for the dialog element.

When the showModal() method is invoked, the user agent must run the following steps:

1. Let subject be the dialog element on which the method was invoked.

2. If subject already has an open attribute, then throw an " InvalidStateError " DOMException .

3. If subject is not connected , then throw an " InvalidStateError " DOMException .

4. Add an open attribute to subject , whose value is the empty string.

5. Set the is modal flag of subject to true.

6. Let subject 's node document be blocked by the modal dialog subject .

   This will cause the focused area of the document to become inert (unless that currently focused area is a shadow-including descendant of subject ). In such cases, the focus fixup rule will kick in and reset the focused area of the document to the viewport for now. In a couple steps we will attempt to find a better candidate to focus.

7. If subject 's node document 's top layer does not already contain subject , then add subject to subject 's node document 's top layer .

8. Run the dialog focusing steps for subject .

The dialog focusing steps for a dialog element subject are as follows:

1. If subject is inert , return.

2. Let control be the first descendant element of subject , in tree order , that is not inert and has the autofocus attribute specified.

   If there isn't one, then let control be the first non- inert descendant element of subject , in tree order.

   If there isn't one of those either, then let control be subject .

3. Run the focusing steps for control .

   If control is not focusable , this will do nothing. For modal dialogs, this means that any earlier modifications to the focused area of the document will apply.

4. Let topDocument be the active document of control 's node document 's browsing context 's top-level browsing context .

5. If control 's node document 's origin is not the same as the origin of topDocument , then return.

6. Empty topDocument 's autofocus candidates .

7. Set topDocument 's autofocus processed flag to true.

If at any time a dialog element is removed from a Document , then if that dialog is in that Document 's top layer , it must be removed from it.

When the close() method is invoked, the user agent must close the dialog that the method was invoked on. If the method was invoked with an argument, that argument must be used as the return value; otherwise, there is no return value.

When a dialog element subject is to be closed , optionally with a return value result , the user agent must run the following steps:

1. If subject does not have an open attribute, then return.

2. Remove subject 's open attribute.

3. Set the is modal flag of subject to false.

4. If the argument result was provided, then set the returnValue attribute to the value of result .

5. If subject is in its Document 's top layer , then remove it.

6. Queue an element task on the user interaction task source given the subject element to fire an event named close at subject .

The returnValue IDL attribute, on getting, must return the last value to which it was set. On setting, it must be set to the new value. When the element is created, it must be set to the empty string.

Canceling dialogs : When Document is blocked by a modal dialog dialog , user agents may provide a user interface that, upon activation, queues an element task on the user interaction task source given the dialog element to run these steps:

1. Let close be the result of firing an event named cancel at dialog , with the cancelable attribute initialized to true.

2. If close is true and dialog has an open attribute, then close the dialog with no return value.

An example of such a UI mechanism would be the user pressing the "Escape" key.

Each dialog element has an is modal flag. When a dialog element is created, this flag must be set to false.

The open IDL attribute must reflect the open content attribute.

<dialog>
 <h1>Add to Wallet</h1>
 <p><strong><label for=amt>How many gold coins do you want to add to your wallet?</label></strong></p>
 <p><input id=amt name=amt type=number min=0 step=0.01 value=100></p>
 <p><small>You add coins at your own risk.</small></p>
 <p><label><input name=round type=checkbox> Only add perfectly round coins </label></p>
 <p><input type=button onclick="submit()" value="Add Coins"></p>
</dialog>