HTML

Living Standard — Last Updated 26 June 2023

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
      5. 4.11.5 The dialogmodal target attributes

4.11 Interactive elements

4.11.1 The details element

Categories :

Flow content .

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.

The ancestor details revealing algorithm is to run the following steps on currentNode :

1. While currentNode has a parent node within the flat tree :

   1. If currentNode is slotted into the second slot of a details element:

      1. Set currentNode to the details element which currentNode is slotted into.

      2. If the open attribute is not set on currentNode , then set the open attribute on currentNode to the empty string.

   2. Otherwise, set currentNode to the parent node of currentNode within the flat tree .

<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 .

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 transitory part of an application, in the form of a small window ("dialog box"), which the user interacts with to perform a task or gather information. Once the user is done, the dialog can be automatically closed by the application, or manually closed by the user.

Especially for modal dialogs, which are a familiar pattern across all types of applications, authors should work to ensure that dialogs in their web applications behave in a way that is familiar to users of non-web applications.

As with all HTML elements, it is not conforming to use the dialog element when attempting to represent another type of control. For example, context menus, tooltips, and popup listboxes are not dialog boxes, so abusing the dialog element to implement these patterns is incorrect.

An important part of user-facing dialog behavior is the placement of initial focus. The dialog focusing steps attempt to pick a good candidate for initial focus when a dialog is shown, but might not be a substitute for authors carefully thinking through the correct choice to match user expectations for a specific dialog. As such, authors should use the autofocus attribute on the descendant element of the dialog that the user is expected to immediately interact with after the dialog opens. If there is no such element, then authors should use the autofocus attribute on the dialog element itself.

<dialog>
  <label>Product Number <input type="text" readonly></label>
  <label>Product Name <input type="text" autofocus></label>
</dialog>

Another important aspect of user behavior is whether dialogs are scrollable or not. In some cases, overflow (and thus scrollability) cannot be avoided, e.g., when it is caused by the user's high text zoom settings. But in general, scrollable dialogs are not expected by users. Adding large text nodes directly to dialog elements is particularly bad as this is likely to cause the dialog element itself to overflow. Authors are best off avoiding them.

<dialog style="height: 80vh;">
  <div style="overflow: auto; height: 60vh;" autofocus>
    <p>By placing an order via this Web site on the first day of the fourth month of the year
    2010 Anno Domini, you agree to grant Us a non-transferable option to claim, for now and for
    ever more, your immortal soul.</p>
    <p>Should We wish to exercise this option, you agree to surrender your immortal soul,
    and any claim you may have on it, within 5 (five) working days of receiving written
    notification from  this site or one of its duly authorized minions.</p>
    <!-- ... etc., with many more <p> elements ... -->
  </div>
  <form method="dialog">
    <button type="submit" value="agree">Agree</button>
    <button type="submit" value="disagree">Disagree</button>
  </form>
</dialog>

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 ()

✔ MDN

HTMLDialogElement/show

Support in all current engines.

Firefox 98+ Safari 15.4+ Chrome 37+

---

Opera ? Edge 79+

---

Edge (Legacy) ? Internet Explorer No

---

Firefox Android ? Safari iOS ? Chrome Android ? WebView Android ? Samsung Internet ? Opera Android ?

Displays the dialog element.

dialog . showModal ()

✔ MDN

HTMLDialogElement/showModal

Support in all current engines.

Firefox 98+ Safari 15.4+ Chrome 37+

---

Opera ? Edge 79+

---

Edge (Legacy) ? Internet Explorer No

---

Firefox Android ? Safari iOS ? Chrome Android ? WebView Android ? Samsung Internet ? Opera Android ?

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

This method honors the autofocus attribute.

dialog . close ([ result ])

✔ MDN

HTMLDialogElement/close

Support in all current engines.

Firefox 98+ Safari 15.4+ Chrome 37+

---

Opera ? Edge 79+

---

Edge (Legacy) ? Internet Explorer No

---

Firefox Android ? Safari iOS ? Chrome Android ? WebView Android ? Samsung Internet ? Opera Android ?

Closes the dialog element.

The argument, if provided, provides a return value.

dialog . returnValue [ = result ]

✔ MDN

HTMLDialogElement/returnValue

Support in all current engines.

Firefox 98+ Safari 15.4+ Chrome 37+

---

Opera ? Edge 79+

---

Edge (Legacy) ? Internet Explorer No

---

Firefox Android ? Safari iOS ? Chrome Android ? WebView Android ? Samsung Internet ? Opera Android ?

Returns the dialog 's return value.

Can be set, to update the return value.

The show() method steps are:

1. If this has an open attribute, then return.

2. If this is in the popover showing state , then throw an " InvalidStateError " DOMException .

3. Add an open attribute to this , whose value is the empty string.

4. Set this 's previously focused element to the focused element.

5. Run the dialog focusing steps given this and false.

The showModal() method steps are:

1. If this has an open attribute, then throw an " InvalidStateError " DOMException .

2. If this is not connected , then throw an " InvalidStateError " DOMException .

3. If this is in the popover showing state , then throw an " InvalidStateError " DOMException .

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

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

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

   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 focused area of the document will soon be reset to the viewport . In a couple steps we will attempt to find a better candidate to focus.

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

8. Set this 's previously focused element to the focused element.

9. Run the dialog focusing steps given this and true.

The dialog focusing steps , given a dialog element subject and a boolean isModal , are as follows:

1. Run hide all popovers given subject 's node document .

2. Let control be null.

3. If isModal is true and subject has the autofocus attribute, then set control to subject .

4. If control is null, then set control to the focus delegate of subject .

5. If control is null, then set control to subject .

6. Run the focusing steps for control .

   If control is not focusable , this will do nothing. This would only happen if subject had no focus delegate, and the user agent decided that dialog elements were not generally focusable. In that case, any earlier modifications to the focused area of the document will apply.

7. Let topDocument be control 's node navigable 's top-level traversable 's active document .

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

9. Empty topDocument 's autofocus candidates .

10. 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. Also, set the dialog element's is modal flag to false.

The close( returnValue ) method steps are:

1. If returnValue is not given, then set it to null.

2. Close the dialog this with returnValue .

When a dialog element subject is to be closed , with null or a string result , run these 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 result is not null, then set the returnValue attribute to result .

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

6. If subject 's previously focused element is not null, then:

   1. Let element be subject 's previously focused element .

   2. Set subject 's previously focused element to null.

   3. Run the focusing steps for element ; the viewport should not be scrolled by doing this step.

7. 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, then close the dialog dialog with null.

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.

Each HTML element has a previously focused element which is null or an element, and it is initially null. When showModal() and show() are called, this element is set to the currently focused element before running the dialog focusing steps . Elements with the popover attribute set this element to the currently focused element during the show popover algorithm .

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>

4.11.5 The dialogmodal target attributes

Buttons may have the following content attributes:

• dialogmoddaltarget

If specified, the dialogmodaltarget attribute value must be the ID of a dialog element in the same tree as the button with the dialogmodaltarget attribute.

<button dialogmodaltarget="foo">
  Show a dialog (modal)
</button>
<dialog id="foo">
  This is a dialog!
  <button dialogmodaltarget="foo">Close</button>
</article>

interface mixin DialogInvokerElement {
  [CEReactions] attribute Element? dialogModalTargetElement;
};

The dialogModalTargetElement IDL attribute must reflect the dialogmodaltarget attribute.

To run the dialog modal target attribute activation behavior given a Node node :

1. Let dialog be node 's dialog modal target element .

2. If dialog is null, then return.

3. If the open attribute is set on node then:

   1. Run close()

      on node

   2. Otherwise, run showModal() on node

To get the dialog modal target element given a Node node , perform the following steps. They return an HTML element or null.

1. If node is not a button , then return null.

2. If node is disabled , then return null.

3. If node 's popovertarget is set, then return null.

4. If node has a form owner and node is a submit button , then return null.

5. Let dialogElement be node 's dialogmodaltarget -associated element .

6. If dialogElement is null, then return null.

7. If dialogElement is not a dialog element, then return null.

8. Return dialogElement .