当前位置：文江博客知识库 en-US 文档 Web API Element

Element - Web APIs 编辑

Element is the most general base class from which all element objects (i.e. objects that represent elements) in a Document inherit. It only has methods and properties common to all kinds of elements. More specific classes inherit from Element. For example, the HTMLElement interface is the base interface for HTML elements, while the SVGElement interface is the basis for all SVG elements. Most functionality is specified further down the class hierarchy.

Languages outside the realm of the Web platform, like XUL through the XULElement interface, also implement Element.

  <div id="interfaceDiagram" style="display: inline-block; position: relative; width: 100%; padding-bottom: 11.666666666666666%; vertical-align: middle; overflow: hidden;"><svg style="display: inline-block; position: absolute; top: 0; left: 0;" viewbox="-50 0 600 70" preserveAspectRatio="xMinYMin meet"><a xlink:href="https://developer.mozilla.org/wiki/en-US/docs/Web/API/EventTarget" target="_top"><rect x="1" y="1" width="110" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="56" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">EventTarget</text></a><polyline points="111,25  121,20  121,30  111,25" stroke="#D4DDE4" fill="none"/><line x1="121" y1="25" x2="151" y2="25" stroke="#D4DDE4"/><a xlink:href="https://developer.mozilla.org/wiki/en-US/docs/Web/API/Node" target="_top"><rect x="151" y="1" width="75" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="188.5" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">Node</text></a><polyline points="226,25  236,20  236,30  226,25" stroke="#D4DDE4" fill="none"/><line x1="236" y1="25" x2="266" y2="25" stroke="#D4DDE4"/><a xlink:href="https://developer.mozilla.org/wiki/en-US/docs/Web/API/Element" target="_top"><rect x="266" y="1" width="75" height="50" fill="#F4F7F8" stroke="#D4DDE4" stroke-width="2px" /><text  x="303.5" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">Element</text></a></svg></div>

  a:hover text { fill: #0095DD; pointer-events: all;}

Properties

Inherits properties from its parent interface, Node, and by extension that interface's parent, EventTarget. It implements the properties of ParentNode, ChildNode, NonDocumentTypeChildNode, and Animatable.

Element.attributes Read only: Returns a NamedNodeMap object containing the assigned attributes of the corresponding HTML element.
Element.classList Read only: Returns a DOMTokenList containing the list of class attributes.
Element.className: Is a DOMString representing the class of the element.
Element.clientHeight Read only: Returns a Number representing the inner height of the element.
Element.clientLeft Read only: Returns a Number representing the width of the left border of the element.
Element.clientTop Read only: Returns a Number representing the width of the top border of the element.
Element.clientWidth Read only: Returns a Number representing the inner width of the element.
Element.computedName Read only: Returns a DOMString containing the label exposed to accessibility.
Element.computedRole Read only: Returns a DOMString containing the ARIA role that has been applied to a particular element.
Element.id: Is a DOMString representing the id of the element.
Element.innerHTML: Is a DOMString representing the markup of the element's content.
Element.localName Read only: A DOMString representing the local part of the qualified name of the element.
Element.namespaceURI Read only: The namespace URI of the element, or null if it is no namespace.
Note: In Firefox 3.5 and earlier, HTML elements are in no namespace. In later versions, HTML elements are in the http://www.w3.org/1999/xhtml namespace in both HTML and XML trees.
NonDocumentTypeChildNode.nextElementSibling Read only: Is an Element, the element immediately following the given one in the tree, or null if there's no sibling node.
Element.outerHTML: Is a DOMString representing the markup of the element including its content. When used as a setter, replaces the element with nodes parsed from the given string.
Element.part: Represents the part identifier(s) of the element (i.e. set using the part attribute), returned as a DOMTokenList.
Element.prefix Read only: A DOMString representing the namespace prefix of the element, or null if no prefix is specified.
NonDocumentTypeChildNode.previousElementSibling Read only: Is a Element, the element immediately preceding the given one in the tree, or null if there is no sibling element.
Element.scrollHeight Read only: Returns a Number representing the scroll view height of an element.
Element.scrollLeft: Is a Number representing the left scroll offset of the element.
Element.scrollLeftMax Read only: Returns a Number representing the maximum left scroll offset possible for the element.
Element.scrollTop: A Number representing number of pixels the top of the document is scrolled vertically.
Element.scrollTopMax Read only: Returns a Number representing the maximum top scroll offset possible for the element.
Element.scrollWidth Read only: Returns a Number representing the scroll view width of the element.
Element.shadowRootRead only: Returns the open shadow root that is hosted by the element, or null if no open shadow root is present.
Element.openOrClosedShadowRoot Read only: Returns the shadow root that is hosted by the element, regardless if its open or closed. Available only to WebExtensions.
Element.slot: Returns the name of the shadow DOM slot the element is inserted in.
Element.tabStop: Is a Boolean indicating if the element can receive input focus via the tab key.
Element.tagName Read only: Returns a String with the name of the tag for the given element.
Element.undoManager Read only: Returns the UndoManager associated with the element.
Element.undoScope: Is a Boolean indicating if the element is an undo scope host, or not.

Note: DOM Level 3 defined namespaceURI, localName and prefix on the Node interface. In DOM4 they were moved to Element.

This change is implemented in Chrome since version 46.0 and Firefox since version 48.0.

Properties included from Slotable

The Element interface includes the following property, defined on the Slotable mixin.

Slotable.assignedSlotRead only: Returns a HTMLSlotElement representing the <slot> the node is inserted in.

Event handlers

Element.onfullscreenchange: An event handler for the fullscreenchange event, which is sent when the element enters or exits full-screen mode. This can be used to watch both for successful expected transitions, but also to watch for unexpected changes, such as when your app is running in the background.
Element.onfullscreenerror: An event handler for the fullscreenerror event, which is sent when an error occurs while attempting to change into full-screen mode.

Methods

Inherits methods from its parents Node, and its own parent, EventTarget, and implements those of ParentNode, ChildNode, NonDocumentTypeChildNode, and Animatable.

EventTarget.addEventListener(): Registers an event handler to a specific event type on the element.
Element.attachShadow(): Attaches a shadow DOM tree to the specified element and returns a reference to its ShadowRoot.
Element.animate(): A shortcut method to create and run an animation on an element. Returns the created Animation object instance.
Element.closest(): Returns the Element which is the closest ancestor of the current element (or the current element itself) which matches the selectors given in parameter.
Element.createShadowRoot(): Creates a shadow DOM on the element, turning it into a shadow host. Returns a ShadowRoot.
Element.computedStyleMap(): Returns a StylePropertyMapReadOnly interface which provides a read-only representation of a CSS declaration block that is an alternative to CSSStyleDeclaration.
EventTarget.dispatchEvent(): Dispatches an event to this node in the DOM and returns a Boolean that indicates whether no handler canceled the event.
Element.getAnimations(): Returns an array of Animation objects currently active on the element.
Element.getAttribute(): Retrieves the value of the named attribute from the current node and returns it as an Object.
Element.getAttributeNames(): Returns an array of attribute names from the current element.
Element.getAttributeNS(): Retrieves the value of the attribute with the specified name and namespace, from the current node and returns it as an Object.
Element.getBoundingClientRect(): Returns the size of an element and its position relative to the viewport.
Element.getClientRects(): Returns a collection of rectangles that indicate the bounding rectangles for each line of text in a client.
Element.getElementsByClassName(): Returns a live HTMLCollection that contains all descendants of the current element that possess the list of classes given in the parameter.
Element.getElementsByTagName(): Returns a live HTMLCollection containing all descendant elements, of a particular tag name, from the current element.
Element.getElementsByTagNameNS(): Returns a live HTMLCollection containing all descendant elements, of a particular tag name and namespace, from the current element.
Element.hasAttribute(): Returns a Boolean indicating if the element has the specified attribute or not.
Element.hasAttributeNS(): Returns a Boolean indicating if the element has the specified attribute, in the specified namespace, or not.
Element.hasAttributes(): Returns a Boolean indicating if the element has one or more HTML attributes present.
Element.hasPointerCapture(): Indicates whether the element on which it is invoked has pointer capture for the pointer identified by the given pointer ID.
Element.insertAdjacentElement(): Inserts a given element node at a given position relative to the element it is invoked upon.
Element.insertAdjacentHTML(): Parses the text as HTML or XML and inserts the resulting nodes into the tree in the position given.
Element.insertAdjacentText(): Inserts a given text node at a given position relative to the element it is invoked upon.
Element.matches(): Returns a Boolean indicating whether or not the element would be selected by the specified selector string.
Element.pseudo(): Returns a CSSPseudoElement representing the child pseudo-element matched by the specified pseudo-element selector.
Element.querySelector(): Returns the first Node which matches the specified selector string relative to the element.
Element.querySelectorAll(): Returns a NodeList of nodes which match the specified selector string relative to the element.
Element.releasePointerCapture(): Releases (stops) pointer capture that was previously set for a specific pointer event.
ChildNode.remove(): Removes the element from the children list of its parent.
Element.removeAttribute(): Removes the named attribute from the current node.
Element.removeAttributeNS(): Removes the attribute with the specified name and namespace, from the current node.
EventTarget.removeEventListener(): Removes an event listener from the element.
Element.requestFullscreen(): Asynchronously asks the browser to make the element full-screen.
Element.requestPointerLock(): Allows to asynchronously ask for the pointer to be locked on the given element.
Element.scroll(): Scrolls to a particular set of coordinates inside a given element.
Element.scrollBy(): Scrolls an element by the given amount.
Element.scrollIntoView(): Scrolls the page until the element gets into the view.
Element.scrollTo(): Scrolls to a particular set of coordinates inside a given element.
Element.setAttribute(): Sets the value of a named attribute of the current node.
Element.setAttributeNS(): Sets the value of the attribute with the specified name and namespace, from the current node.
Element.setCapture(): Sets up mouse event capture, redirecting all mouse events to this element.
Element.setPointerCapture(): Designates a specific element as the capture target of future pointer events.
Element.toggleAttribute(): Toggles a boolean attribute, removing it if it is present and adding it if it is not present, on the specified element.
Obsolete methods
Element.getAttributeNode(): Retrieves the node representation of the named attribute from the current node and returns it as an Attr.
Element.getAttributeNodeNS(): Retrieves the node representation of the attribute with the specified name and namespace, from the current node and returns it as an Attr.
Element.removeAttributeNode(): Removes the node representation of the named attribute from the current node.
Element.setAttributeNode(): Sets the node representation of the named attribute from the current node.
Element.setAttributeNodeNS(): Sets the node representation of the attribute with the specified name and namespace, from the current node.

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

cancel: Fires on a <dialog> when the user instructs the browser that they wish to dismiss the current open dialog. For example, the browser might fire this event when the user presses the Esc key or clicks a "Close dialog" button which is part of the browser's UI.
Also available via the oncancel property.
error: Fired when a resource failed to load, or can't be used. For example, if a script has an execution error or an image can't be found or is invalid.
Also available via the onerror property.
scroll: Fired when the document view or an element has been scrolled.
Also available via the onscroll property.
select: Fired when some text has been selected.
Also available via the onselect property.
show: Fired when a contextmenu event was fired on/bubbled to an element that has a contextmenu attribute.
Also available via the onshow property.
wheel: Fired when the user rotates a wheel button on a pointing device (typically a mouse).
Also available via the onwheel property.

Clipboard events

copy: Fired when the user initiates a copy action through the browser's user interface.
Also available via the oncopy property.
cut: Fired when the user initiates a cut action through the browser's user interface.
Also available via the oncut property.
paste: Fired when the user initiates a paste action through the browser's user interface.
Also available via the onpaste property.

Composition events

compositionend: Fired when a text composition system such as an input method editor completes or cancels the current composition session.
compositionstart: Fired when a text composition system such as an input method editor starts a new composition session.
compositionupdate: Fired when a new character is received in the context of a text composition session controlled by a text composition system such as an input method editor.

Focus events

blur: Fired when an element has lost focus.
Also available via the onblur property.
focus: Fired when an element has gained focus.
Also available via the onfocus property
focusin: Fired when an element is about to gain focus.
focusout: Fired when an element is about to lose focus.

Fullscreen events

fullscreenchange: Sent to an Element when it transitions into or out of full-screen mode.
Also available via the onfullscreenchange property.
fullscreenerror: Sent to an Element if an error occurs while attempting to switch it into or out of full-screen mode.
Also available via the onfullscreenerror property.

Keyboard events

keydown: Fired when a key is pressed.
Also available via the onkeydown property.
keypress: Fired when a key that produces a character value is pressed down.
Also available via the onkeypress property.
keyup: Fired when a key is released.
Also available via the onkeyup property.

Mouse events

auxclick: Fired when a non-primary pointing device button (e.g., any mouse button other than the left button) has been pressed and released on an element.
Also available via the onauxclick property.
click: Fired when a pointing device button (e.g., a mouse's primary button) is pressed and released on a single element.
Also available via the onclick property.
contextmenu: Fired when the user attempts to open a context menu.
Also available via the oncontextmenu property.
dblclick: Fired when a pointing device button (e.g., a mouse's primary button) is clicked twice on a single element.
Also available via the ondblclick property.
DOMActivate: Occurs when an element is activated, for instance, through a mouse click or a keypress.
mousedown: Fired when a pointing device button is pressed on an element.
Also available via the onmousedown property.
mouseenter: Fired when a pointing device (usually a mouse) is moved over the element that has the listener attached.
Also available via the onmouseenter property.
mouseleave: Fired when the pointer of a pointing device (usually a mouse) is moved out of an element that has the listener attached to it.
Also available via the onmouseleave property.
mousemove: Fired when a pointing device (usually a mouse) is moved while over an element.
Also available via the onmousemove property.
mouseout: Fired when a pointing device (usually a mouse) is moved off the element to which the listener is attached or off one of its children.
Also available via the onmouseout property.
mouseover: Fired when a pointing device is moved onto the element to which the listener is attached or onto one of its children.
Also available via the onmouseover property.
mouseup: Fired when a pointing device button is released on an element.
Also available via the onmouseup property.
webkitmouseforcechanged: Fired each time the amount of pressure changes on the trackpadtouchscreen.
webkitmouseforcedown: Fired after the mousedown event as soon as sufficient pressure has been applied to qualify as a "force click".
webkitmouseforcewillbegin: Fired before the mousedown event.
webkitmouseforceup: Fired after the webkitmouseforcedown event as soon as the pressure has been reduced sufficiently to end the "force click".

Touch events

touchcancel: Fired when one or more touch points have been disrupted in an implementation-specific manner (for example, too many touch points are created).
Also available via the ontouchcancel property.
touchend: Fired when one or more touch points are removed from the touch surface.
Also available via the ontouchend property
touchmove: Fired when one or more touch points are moved along the touch surface.
Also available via the ontouchmove property
touchstart: Fired when one or more touch points are placed on the touch surface.
Also available via the ontouchstart property

Specifications

Specification	Status	Comment
CSS Pseudo-Elements Level 4 The definition of 'Element' in that specification.	Working Draft	Added the `pseudo()` method.
Web Animations	Working Draft	Added the `getAnimations()` method.
UndoManager and DOMTransaction The definition of 'Element' in that specification.	Editor's Draft	Added the `undoScope` and `undoManager` properties.
Pointer Events – Level 2 The definition of 'Element' in that specification.	Recommendation	Added the following event handlers: `ongotpointercapture` and `onlostpointercapture`. Added the following methods: `setPointerCapture()` and `releasePointerCapture()`.
Pointer Events The definition of 'Element' in that specification.	Obsolete	Added the following event handlers: `ongotpointercapture` and `onlostpointercapture`. Added the following methods: `setPointerCapture()` and `releasePointerCapture()`.
Selectors API Level 1 The definition of 'Element' in that specification.	Obsolete	Added the following methods: `querySelector()` and `querySelectorAll()`.
Pointer Lock The definition of 'Element' in that specification.	Candidate Recommendation	Added the `requestPointerLock()` method.
Fullscreen API The definition of 'Element' in that specification.	Living Standard	Added the `requestFullscreen()` method.
DOM Parsing and Serialization The definition of 'Element' in that specification.	Working Draft	Added the following properties: `innerHTML`, and `outerHTML`. Added the following method: `insertAdjacentHTML()`.
CSS Object Model (CSSOM) View Module The definition of 'Element' in that specification.	Working Draft	Added the following properties: `scrollTop`, `scrollLeft`, `scrollWidth`, `scrollHeight`, `clientTop`, `clientLeft`, `clientWidth`, and `clientHeight`. Added the following methods: `getClientRects()`, `getBoundingClientRect()`, `scroll()`, `scrollBy()`, `scrollTo()` and `scrollIntoView()`.
Element Traversal Specification The definition of 'Element' in that specification.	Obsolete	Added inheritance of the `ElementTraversal` interface.
DOM The definition of 'Element' in that specification.	Living Standard	Added the following methods: `closest()`, `insertAdjacentElement()` and `insertAdjacentText()`. Moved `hasAttributes()` from the `Node` interface to this one.
DOM4 The definition of 'Element' in that specification.	Obsolete	Removed the following methods: `setIdAttribute()`, `setIdAttributeNS()`, and `setIdAttributeNode()`. Modified the return value of `getElementsByTagName()` and `getElementsByTagNameNS()`. Removed the `schemaTypeInfo` property.
Document Object Model (DOM) Level 3 Core Specification The definition of 'Element' in that specification.	Obsolete	Added the following methods: `setIdAttribute()`, `setIdAttributeNS()`, and `setIdAttributeNode()`. These methods were never implemented and have been removed in later specifications. Added the `schemaTypeInfo` property. This property was never implemented and has been removed in later specifications.
Document Object Model (DOM) Level 2 Core Specification The definition of 'Element' in that specification.	Obsolete	The `normalize()` method has been moved to `Node`.
Document Object Model (DOM) Level 1 Specification The definition of 'Element' in that specification.	Obsolete	Initial definition.