Element

Element（元素）接口是 Document的一个对象. 这个接口描述了所有相同种类的元素所普遍具有的方法和属性。 这些继承自Element并且增加了一些额外功能的接口描述了具体的行为. 例如,  HTMLElement 接口是所有HTML元素的基础接口， 而 SVGElement 接口是所有SVG元素的基本接口.

在web以外的语言,像 XUL 可以通过 XULElement 的API, 也能实现它.

属性

所有属性继承至它的祖先 Node, 和父元素, EventTarget, 并且具备以下属性ParentNode, ChildNode, NonDocumentTypeChildNode, 和Animatable.

Element.attributes 只读

返回一个与该元素相关的所有属性集合NamedNodeMap 

ParentNode.childElementCount 只读

它是一个Number 表示该元素有多少个子节点.

ParentNode.children 只读

它是一个该元素下所有子元素的HTMLCollection 集合

Element.classList 只读

返回该元素包含的class属性是一个DOMTokenList.

Element.className

它是一个 DOMString 表示这个元素的class.

Element.clientHeight 只读

返回Number 表示内部相对于外层元素的高度.

Element.clientLeft 只读

返回Number表示该元素距离它左边界的宽度.

Element.clientTop 只读

返回 Number 表示该元素距离它上边界的高度.

Element.clientWidth 只读

返回Number 表示该元素它内部的宽度.

ParentNode.firstElementChild 只读

是一个Element, 直接获取该元素下第一个子元素，如果为null表示不存在.

Element.id

是一个DOMString 表示这个元素的id.

Element.innerHTML 

是一个DOMString 表示这个元素的内容文本

ParentNode.lastElementChild 只读

是一个Element, 直接获取该元素下最后一个子元素，如果为null表示不存在.

Element.namespaceURI 只读

The namespace URI of this element, or null if it is no namespace. In Firefox 3.5 and earlier, HTML elements are in no namespace. In later versions, HTML elements are in the https://www.w3.org/1999/xhtml namespace in both HTML and XML trees.
Though recent specifications require namespaceURI to be defined on the Element interface, Gecko-based browsers still implement it on the Node interface.

NonDocumentTypeChildNode.nextElementSibling 只读

是一个Element, 该元素下一个兄弟节点, 如果为null表示不存在..

Element.outerHTML

是一个 DOMString获取该DOM元素及其后代的HTML文本.当设置它的时候,会从给定的字符串开始解析，替换自身。

NonDocumentTypeChildNode.previousElementSibling 只读

是一个Element, 该元素上一个兄弟节点, 如果为null表示不存在..

Element.scrollHeight 只读

返回 Number 表示该元素可见高度的滚动条.

Element.scrollLeft

返回 Number表示该元素横向滚动条距离最左的位移.

Element.scrollLeftMax 只读

返回 Number 表示该元素横向滚动条可移动的最大值

Element.scrollTop

是一个Number 表示该元素纵向滚动条距离

Element.scrollTopMax 只读

返回 Number 表示该元素纵向滚动条可移动的最大值

Element.scrollWidth 只读

返回 Number representing the scroll view width of the element.

Element.shadowRoot 只读

Returns the youngest shadow root that is hosted by the element.

Element.tabStop

Is a Boolean indicating if the element can receive input focus via the tab key.

Element.tagName 只读

返回 String表示该元素的标签名

Element.undoManager 只读

Returns the UndoManager associated with the element.

Element.undoScope

Is a Boolean indicating if the element is an undo scope host, or not.

事件句柄

Element.ongotpointercapture

Returns the event handler for the gotpointercapture event type.

Element.onlostpointercapture

Returns the event handler for the lostpointercapture event type.

Element.onwheel

Returns the event handling code for the wheel event.

方法

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.closest()

Returns the Element, descendant of this element (or this element itself), that is the closest ancestor of the elements selected by the selectors given in parameter.

Element.createShadowRoot()  

Creates a shadow DOM on on the element, turning it into a shadow host. Returns a ShadowRoot.

EventTarget.dispatchEvent()

Dispatches an event to this node in the DOM and returns a Boolean that indicates that at least one handler has not canceled it.

Element.find()

...

Element.findAll()

...

Animatable.getAnimationPlayers()

…

Element.getAttribute()

Retrieves the value of the named attribute from the current node and returns it as an Object.

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.getAttributeNode()

Retrievse 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.getBoundingClientRect()

...

Element.getClientRects()

Returns a collection of rectangles that indicate the bounding rectangles for each line of text in a client.

Element.getDestinationInsertionPoints()

…

Element.getElementsByClassName()

参数中给出类的列表，返回一个动态的 HTMLCollection ，这里面包含了所有持有这些类的后代元素

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.insertAdjacentHTML

Parses the text as HTML or XML and inserts the resulting nodes into the tree in the position given.

Element.matches()

Returns a Boolean indicating whether or not the element would be selected by the specified selector string.

Element.querySelector()

Returns Node...

Element.querySelectorAll

Returns a NodeList...

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.

Element.removeAttributeNode()

Removes the node representation of the named attribute 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.scrollIntoView()

Scrolls the page until the element gets into the view.

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.setAttributeNode()

Sets the node representation of the named attribute from the current node.

Element.setAttributeNodeNS()

Setw the node representation 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.

规范

浏览器兼容性

[1] Internet Explorer 7 and 8 incorrectly return the comments as part of the children of an Element. This is fixed in Internet Explorer 9 and later.

[2] Chrome 16 allowed webkitRequestPointerLock() only in fullscreen; Chrome 21 for trusted web site (permission asked); Chrome 22 allowed it by default for all same-origin document; Chrome 23 allowed it in sandboxed <iframe> if the non-standard value webkit-allow-pointer-lock is set to the sandbox attribute.