Living Standard — Last Updated 8 November 2024
details
elementsummary
elementa
element to define a commandbutton
element to define a commandinput
element to define a commandoption
element to define a commandaccesskey
attribute
on a legend
element to define a commandaccesskey
attribute to define a command on other elementsdialog
elementdetails
elementSupport in all current engines.
Support in all current engines.
summary
element followed by flow content.name
— Name of group of mutually-exclusive details
elements
open
— Whether the details are visible
[Exposed =Window ]
interface HTMLDetailsElement : HTMLElement {
[HTMLConstructor ] constructor ();
[CEReactions ] attribute DOMString name ;
[CEReactions ] attribute boolean open ;
};
The details
element represents a disclosure widget from which the
user can obtain additional information or controls.
As with all HTML elements, it is not conforming to use the details
element when attempting to represent another type of control. For example, tab widgets and
menu widgets are not disclosure widgets, so abusing the details
element to
implement these patterns is incorrect.
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 name
content
attribute gives the name of the group of related details
elements that the element is
a member of. Opening one member of this group causes other members of the group to close. If the
attribute is specified, its value must not be the empty string.
Before using this feature, authors should consider whether this grouping of related
details
elements into an exclusive accordion is helpful or harmful to users.
While using an exclusive accordion can reduce the maximum amount of space that a set of content
can occupy, it can also frustrate users who have to open many items to find what they want or
users who want to look at the contents of multiple items at the same time.
A document must not contain more than one details
element in the same
details name group that has the open
attribute present. Authors must not use script to add details
elements to a document
in a way that would cause a details name group to have more than one
details
element with the open
attribute
present.
The group of elements that is created by a common name
attribute is exclusive, meaning that at most one of the
details
elements can be open at once. While this exclusivity is enforced by user
agents, the resulting enforcement immediately changes the open
attributes in the markup. This requirement on authors
forbids such misleading markup.
A document must not contain a details
element that is a descendant of another
details
element in the same details name group.
Documents that use the name
attribute to group multiple
related details
elements should keep those related elements together in a containing
element (such as a section
element or article
element). When it makes
sense for the group to be introduced with a heading, authors should put that heading in a heading element at the start of the containing element.
Visually and programmatically grouping related elements together can be important for accessible user experiences. This can help users understand the relationship between such elements. When related elements are in disparate sections of a web page rather than being grouped, the elements' relationships to each other can be less discoverable or understandable.
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.
The details name group that contains a details
element a
also contains all the other details
elements b that fulfill all of the
following conditions:
name
attribute, their name
attributes are not the empty string, and the value of
a's name
attribute equals the value of
b's name
attribute.Every details
element has a details toggle task tracker, which is a
toggle task tracker or null, initially null.
The following attribute change
steps, given element, localName, oldValue,
value, and namespace, are used for all details
elements:
If namespace is not null, then return.
If localName is name
, then ensure
details exclusivity by closing the given element if needed given
element.
If localName is open
, then:
If one of oldValue or value is null and the other is not null,
run the following steps, which are known as the details notification task steps, for
this details
element:
When the open
attribute is toggled
several times in succession, the resulting tasks essentially get coalesced so that only one
event is fired.
If oldValue is null, queue a details toggle event task given
the details
element, "closed
", and "open
".
Otherwise, queue a details toggle event task given the
details
element, "open
", and "closed
".
If oldValue is null and value is not null, then ensure details exclusivity by closing other elements if needed given element.
The details
HTML element insertion
steps, given insertedNode, are:
Ensure details exclusivity by closing the given element if needed given insertedNode.
To be clear, these attribute change and insertion steps also run when an attribute or element is inserted via the parser.
To queue a details toggle event task given a details
element
element, a string oldState, and a string newState:
If element's details toggle task tracker is not null, then:
Set oldState to element's details toggle task tracker's old state.
Remove element's details toggle task tracker's task from its task queue.
Set element's details toggle task tracker to null.
Queue an element task given the DOM manipulation task source and element to run the following steps:
Fire an event named toggle
at element, using ToggleEvent
, with
the oldState
attribute initialized to
oldState and the newState
attribute
initialized to newState.
Set element's details toggle task tracker to null.
Set element's details toggle task tracker to a struct with task set to the just-queued task and old state set to oldState.
To ensure details exclusivity by closing other elements if needed given a
details
element element:
If element does not have a name
attribute, or its name
attribute is the empty string,
then return.
Let groupMembers be a list of elements, containing all elements in element's details name group except for element, in tree order.
For each element otherElement of groupMembers:
To ensure details exclusivity by closing the given element if needed given a
details
element element:
If element does not have an open
attribute, then return.
If element does not have a name
attribute, or its name
attribute is the empty string,
then return.
Let groupMembers be a list of elements, containing all elements in element's details name group except for element, in tree order.
For each element otherElement of groupMembers:
Support in all current engines.
The name
and open
IDL attributes must reflect the respective content attributes of the same name.
The ancestor details revealing algorithm is to run the following steps on currentNode:
While currentNode has a parent node within the flat tree:
The following example shows the details
element being used to hide technical
details in a progress report.
< 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 >
The following shows how a details
element can be used to hide some controls by
default:
< 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 >
One could use this in conjunction with other details
in a list to allow the user
to collapse a set of fields down to a small set of headings, with the ability to open each
one.
In these examples, the summary really just summarizes what the controls can change, and not the actual values, which is less than ideal.
The following example shows the name
attribute of the
details
element being used to create an exclusive accordion, a set of
details
elements where a user action to open one details
element causes
any open details
to close.
< section class = "characteristics" >
< details name = "frame-characteristics" >
< summary > Material</ summary >
The picture frame is made of solid oak wood.
</ details >
< details name = "frame-characteristics" >
< summary > Size</ summary >
The picture frame fits a photo 40cm tall and 30cm wide.
The frame is 45cm tall, 35cm wide, and 2cm thick.
</ details >
< details name = "frame-characteristics" >
< summary > Color</ summary >
The picture frame is available in its natural wood
color, or with black stain.
</ details >
</ section >
The following example shows what happens when the open
attribute is set on a details
element that is part of a set of elements using the
name
attribute to create an exclusive accordion.
Given the initial markup:
< section class = "characteristics" >
< details name = "frame-characteristics" id = "d1" open > ...</ details >
< details name = "frame-characteristics" id = "d2" > ...</ details >
< details name = "frame-characteristics" id = "d3" > ...</ details >
</ section >
and the script:
document. getElementById( "d2" ). setAttribute( "open" , "" );
then the resulting tree after the script executes will be equivalent to the markup:
< section class = "characteristics" >
< details name = "frame-characteristics" id = "d1" > ...</ details >
< details name = "frame-characteristics" id = "d2" open > ...</ details >
< details name = "frame-characteristics" id = "d3" > ...</ details >
</ section >
because setting the open
attribute on d2
removes it from d1
.
The same happens when the user activates the summary
element inside of d2
.
Because the open
attribute is added and removed
automatically as the user interacts with the control, it can be used in CSS to style the element
differently based on its state. Here, a style sheet is used to animate the color of the summary
when the element is opened or closed:
< style >
details > summary { transition : color 1 s ; color : black ; }
details [ open ] > summary { color : red ; }
</ style >
< details >
< summary > Automated Status: Operational</ summary >
< p > Velocity: 12m/s</ p >
< p > Direction: North</ p >
</ details >
summary
elementSupport in all current engines.
details
element.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:
If this summary
element has no parent, then return false.
Let parent be this summary
element's parent.
If parent is not a details
element, then return false.
If parent's first summary
element child is not this
summary
element, then return false.
Return true.
The activation behavior of summary
elements is to run the following
steps:
If this summary
element is not the summary for its parent
details, then return.
Let parent be this summary
element's parent.
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.
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:
User agents may expose the commands that match the following criteria:
The
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
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.
a
element to define a commandAn 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
of the command is true (hidden) if the element has a 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.
button
element to define a commandA button
element always defines a
command.
The Label, Access Key, , 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.
input
element to define a commandAn 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.
Even though the value
attribute on
input
elements in the Image Button
state is non-conformant, the attribute can still contribute to the Label determination, if it is present and the Image Button's
alt
attribute is missing.
The Access Key of the command is the element's assigned access key, if any.
The
of the command is true (hidden) if the element has a 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.
option
element to define a commandAn 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
of the command is true (hidden) if the element has a 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.
accesskey
attribute
on a legend
element to define a commandA 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 Disabled State, and Action facets of the command are the same as the respective
facets of the legend
element's accesskey
delegatee.
In this example, the legend
element specifies an accesskey
, which, when activated, will delegate to the
input
element inside the legend
element.
< 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 >
accesskey
attribute to define a command on other elementsAn 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
of the command is true (hidden) if the element has a 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:
click
event at the element.dialog
elementSupport in all current engines.
Support in all current engines.
open
— Whether the dialog box is showing
[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.
In the following example, a dialog is used for editing the details of a product in an inventory management web application.
< dialog >
< label > Product Number < input type = "text" readonly ></ label >
< label > Product Name < input type = "text" autofocus ></ label >
</ dialog >
If the autofocus
attribute was not present, the
Product Number field would have been focused by the dialog focusing steps. Although that is
reasonable behavior, the author determined that the more relevant field to focus was the Product
Name field, as the Product Number field is readonly and expects no user input. So, the author
used autofocus to override the default.
Even if the author wants to focus the Product Number field by default, they are best off
explicitly specifying that by using autofocus on that input
element. This makes the
intent obvious to future readers of the code, and ensures the code stays robust in the face of
future updates. (For example, if another developer added a close button, and positioned it in the
node tree before the Product Number field).
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.
The following terms of service dialog respects the above suggestions.
< 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 >
Note how the dialog focusing steps would have picked the scrollable
div
element by default, but similarly to the previous example, we have placed autofocus
on the div
so as to be more explicit and
robust against future changes.
In contrast, if the p
elements expressing the terms of service did not have such
a wrapper div
element, then the dialog
itself would become scrollable,
violating the above advice. Furthermore, in the absence of any autofocus
attribute, such a markup pattern would have violated
the above advice and tripped up the dialog focusing steps's default behavior, and
caused focus to jump to the Agree button
, which is a bad user experience.
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.
Removing the open
attribute will usually hide the
dialog. However, doing so has a number of strange additional consequences:
The close
event will not be fired.
The close()
method, and any close requests, will no longer be able to close the dialog.
If the dialog was shown using its showModal()
method, the Document
will still be blocked.
For these reasons, it is generally better to never remove the open
attribute manually. Instead, use the close()
method to close the dialog, or the attribute to hide it.
The tabindex
attribute must not be specified on
dialog
elements.
dialog.show()
Support in all current engines.
Displays the dialog
element.
dialog.showModal()
Support in all current engines.
Displays the dialog
element and makes it the top-most modal dialog.
This method honors the autofocus
attribute.
dialog.close([ result ])
Support in all current engines.
Closes the dialog
element.
The argument, if provided, provides a return value.
dialog.returnValue [ = result ]
Support in all current engines.
Returns the dialog
's return value.
Can be set, to update the return value.
Every dialog
element has a dialog toggle task tracker, which is a
toggle task tracker or null, initially null.
To queue a dialog toggle event task given a dialog
element
element, a string oldState, and a string newState:
If element's dialog toggle task tracker is not null, then:
Set oldState to element's dialog toggle task tracker's old state.
Remove element's dialog toggle task tracker's task from its task queue.
Set element's dialog toggle task tracker to null.
Queue an element task given the DOM manipulation task source and element to run the following steps:
Fire an event named toggle
at element, using ToggleEvent
, with
the oldState
attribute initialized to
oldState and the newState
attribute
initialized to newState.
Set element's dialog toggle task tracker to null.
Set element's dialog toggle task tracker to a struct with task set to the just-queued task and old state set to oldState.
The show()
method steps are:
If this has an open
attribute and the
is modal flag of this is false, then return.
If this has an open
attribute, then
throw an "InvalidStateError
" DOMException
.
If the result of firing an event named beforetoggle
, using ToggleEvent
, with the cancelable
attribute initialized to true, the oldState
attribute initialized to "closed
", and the newState
attribute initialized to "open
" at this is false, then
return.
Queue a dialog toggle event task given subject, "closed
", and "open
".
Add an open
attribute to this, whose
value is the empty string.
Set this's previously focused element to the focused element.
Let hideUntil be the result of running topmost popover ancestor given this, null, and false.
If hideUntil is null, then set hideUntil to this's node document.
Run hide all popovers until given hideUntil, false, and true.
Run the dialog focusing steps given this.
The showModal()
method steps are:
If this has an open
attribute and the
is modal flag of this is true, then return.
If this has an open
attribute, then
throw an "InvalidStateError
" DOMException
.
If this's node document is not fully active, then
throw an "InvalidStateError
" DOMException
.
If this is not connected, then throw an
"InvalidStateError
" DOMException
.
If this is in the popover showing
state, then throw an "InvalidStateError
"
DOMException
.
If the result of firing an event named beforetoggle
, using ToggleEvent
, with the cancelable
attribute initialized to true, the oldState
attribute initialized to "closed
", and the newState
attribute initialized to "open
" at this is false, then
return.
If this is in the popover showing state, then return.
Queue a dialog toggle event task given subject, "closed
", and "open
".
Add an open
attribute to this, whose
value is the empty string.
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.
If this's node document's top layer does not already contain this, then add an element to the top layer given this.
Set this's close watcher to the result of establishing a close watcher given this's relevant global object, with:
cancelAction given
canPreventClose being to return the result of firing an event named cancel
at this, with the cancelable
attribute initialized to
canPreventClose.
closeAction being to close the dialog given this and null.
Set this's previously focused element to the focused element.
Let hideUntil be the result of running topmost popover ancestor given this, null, and false.
If hideUntil is null, then set hideUntil to this's node document.
Run hide all popovers until given hideUntil, false, and true.
Run the dialog focusing steps given this.
The dialog focusing steps, given a dialog
element subject,
are as follows:
Let control be null.
If subject has the autofocus
attribute, then set control to subject.
If control is null, then set control to the focus delegate of subject.
If control is null, then set control to subject.
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.
Let topDocument be control's node navigable's top-level traversable's active document.
If control's node document's origin is not the same as the origin of topDocument, then return.
Empty topDocument's autofocus candidates.
Set topDocument's autofocus processed flag to true.
The dialog
HTML element removing steps, given removedNode
and oldParent, are:
If removedNode's close watcher is not null, then:
Destroy removedNode's close watcher.
Set removedNode's close watcher to null.
If removedNode's node document's top layer contains removedNode, then remove an element from the top layer immediately given removedNode.
Set the is modal flag of removedNode to false.
The close(returnValue)
method steps are:
If returnValue is not given, then set it to null.
Close the dialog this with returnValue.
When a dialog
element subject is to be closed, with null or a string result, run these steps:
If subject does not have an open
attribute, then return.
Fire an event named beforetoggle
, using ToggleEvent
, with the oldState
attribute initialized to "open
" and the newState
attribute
initialized to "closed
" at subject.
If subject does not have an open
attribute, then return.
Queue a dialog toggle event task given subject, "open
", and "closed
".
Remove subject's open
attribute.
If the is modal flag of subject is true, then request an element to be removed from the top layer given subject.
Let wasModal be the value of subject's is modal flag.
Set the is modal flag of subject to false.
If result is not null, then set the returnValue
attribute to result.
If subject's previously focused element is not null, then:
Let element be subject's previously focused element.
Set subject's previously focused element to null.
If subject's node document's focused area of the document's DOM anchor is a shadow-including inclusive descendant of element, or wasModal is true, then run the focusing steps for element; the viewport should not be scrolled by doing this step.
Queue an element task on the user interaction task source given the
subject element to fire an event named
close
at subject.
If subject's close watcher is not null, then:
Destroy subject's close watcher.
Set subject's close watcher to null.
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.
We use show/close as the verbs for dialog
elements, as opposed to verb pairs that
are more commonly thought of as antonyms such as show/hide or open/close, due to the following
constraints:
Hiding a dialog is different from closing one. Closing a dialog gives it a return value,
fires an event, unblocks the page for other dialogs, and so on. Whereas hiding a dialog is a
purely visual property, and is something you can already do with the open
attribute. (See also the note above about removing the open
attribute, and how hiding the dialog in that way is
generally not desired.)
Showing a dialog is different from opening one. Opening a dialog consists of creating
and showing that dialog (similar to how window.open()
both
creates and shows a new window). Whereas showing the dialog is the process of taking a
dialog
element that is already in the DOM, and making it interactive and visible
to the user.
If we were to have a dialog.open()
method despite the above, it
would conflict with the dialog.open
property.
Furthermore, a survey
of many other UI frameworks contemporary to the original design of the dialog
element made it clear that the show/close verb pair was reasonably common.
In summary, it turns out that the implications of certain verbs, and how they are used in technology contexts, mean that paired actions such as showing and closing a dialog are not always expressible as antonyms.
Each dialog
element has a close watcher,
which is a close watcher or null, initially null.
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.
Support in all current engines.
The open
IDL
attribute must reflect the open
content
attribute.
This dialog box has some small print. The strong
element is used to draw the
user's attention to the more important part.
< 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 >