Specifies an explicit URL used to resolve links and references to external sources such as images and style sheets.

Members Table

The following table lists the members exposed by the base object.

Attributes/Properties

Attribute	Property	Description
aria-activedescendant	ariaActivedescendant	Sets or retrieves the currently active child element.
aria-busy	ariaBusy	Sets or retrieves a value indicating whether a live region is finished updating.
aria-checked	ariaChecked	Sets or retrieves the checked state of this element.
aria-controls	ariaControls	Sets or retrieves the list of elements that are controlled by the current element.
aria-describedby	ariaDescribedby	Sets or retrieves a list of elements that describe the current object.
aria-disabled	ariaDisabled	Sets or retrieves the disabled state of this element.
aria-expanded	ariaExpanded	Sets or retrieves the expanded state of this element.
aria-flowto	ariaFlowto	Sets or retrieves the recommended reading order of content.
aria-haspopup	ariaHaspopup	Sets or retrieves a value indicating whether this element may display a pop-up window.
aria-hidden	ariaHidden	Sets or retrieves the hidden state of this element.
aria-invalid	ariaInvalid	Sets or retrieves the error state of this element.
aria-labelledby	ariaLabelledby	Sets or retrieves a list of elements that provide a label for the current object.
aria-level	ariaLevel	Sets or retrieves the level of this element.
aria-live	ariaLive	Sets or retrieves how assistive technology should announce updates to live regions.
aria-multiselect	ariaMultiselect	Sets or retrieves the multiple-selection state of this element.
aria-owns	ariaOwns	Sets or retrieves a list of child objects, including elements that are not direct descendants of the current object.
aria-posinset	ariaPosinset	Sets or retrieves the current position of an item within a set.
aria-pressed	ariaPressed	Sets or retrieves the pressed state of a button that can be toggled.
aria-readonly	ariaReadonly	Sets or retrieves the read-only state of this element.
aria-relevant	ariaRelevant	Sets or retrieves which changes to a live region are relevant.
aria-required	ariaRequired	Sets or retrieves the form-completion requirement of this element.
aria-secret	ariaSecret	Sets or retrieves the secret state of this element.
aria-selected	ariaSelected	Sets or retrieves the selection state of this element.
aria-setsize	ariaSetsize	Sets or retrieves the set size of this element.
aria-valuemax	ariaValuemax	Sets or retrieves the maximum value that a user can provide.
aria-valuemin	ariaValuemin	Sets or retrieves the minimum value that a user can provide.
aria-valuenow	ariaValuenow	Sets or retrieves the current value of the element.
	attributes	Retrieves a collection of attributes of the object.
canHaveHTML	canHaveHTML	Retrieves the value indicating whether the object can contain rich HTML markup.
	constructor	Returns a reference to the constructor of an object.
	firstChild	Retrieves a reference to the first child in the childNodes collection of the object.
HREF	href	Sets or retrieves the baseline URL on which relative links are based.
ID	id	Sets or retrieves the string identifying the object.
	isContentEditable	Gets the value that indicates whether the user can edit the contents of the object.
	isDisabled	Gets the value that indicates whether the user can interact with the object.
	isMultiLine	Retrieves the value indicating whether the content of the object contains one or more lines.
	isTextEdit	Retrieves whether a TextRange object can be created using the object.
	lastChild	Retrieves a reference to the last child in the childNodes collection of an object.
	nextSibling	Retrieves a reference to the next child of the parent for the object.
	nodeName	Retrieves the name of a particular type of node.
	nodeType	Retrieves the type of the requested node.
	nodeValue	Sets or retrieves the value of a node.
	ownerDocument	Retrieves the document object associated with the node.
	parentElement	Retrieves the parent object in the object hierarchy.
	parentNode	Retrieves the parent object in the document hierarchy.
	parentTextEdit	Retrieves the container object in the document hierarchy that can be used to create a TextRange containing the original object.
	previousSibling	Retrieves a reference to the previous child of the parent for the object.
	readyState	Retrieves the current state of the object.
role	role	Sets or retrieves the role for this element.
	scopeName	Gets the namespace defined for the element.
	sourceIndex	Retrieves the ordinal position of the object, in source order, as the object appears in the document's all collection.
	tagName	Retrieves the tag name of the object.
	tagUrn	Sets or gets the Uniform Resource Name (URN) specified in the namespace declaration.
TARGET	target	Sets or retrieves the window or frame at which to target content.
	uniqueID	Retrieves an autogenerated, unique identifier for the object.

Behaviors

Behavior	Description
clientCaps	Provides information about features supported by Internet Explorer, as well as a way for installing browser components on demand.
download	Downloads a file and notifies a specified callback function when the download is complete.
homePage	Contains information about a user's homepage.

Collections

Collection	Description
all	Returns a reference to the collection of elements contained by the object.
attributes	Retrieves the collection of attributes belonging to the object.
behaviorUrns	Returns a collection of Uniform Resource Name (URN) strings identifying the behaviors attached to the element.
childNodes	Retrieves a collection of HTML Elements and TextNode objects that are direct descendants of the specified object.
children	Retrieves a collection of DHTML Objects that are direct descendants of the object.

Events

Event	Description
onafterupdate	Fires on a databound object after successfully updating the associated data in the data source object.
onbeforecopy	Fires on the source object before the selection is copied to the system clipboard.
onbeforeupdate	Fires on a databound object before updating the associated data in the data source object.
oncellchange	Fires when data changes in the data provider.
oncopy	Fires on the source element when the user copies the object or selection, adding it to the system clipboard.
ondataavailable	Fires periodically as data arrives from data source objects that asynchronously transmit their data.
ondatasetchanged	Fires when the data set exposed by a data source object changes.
ondatasetcomplete	Fires to indicate that all data is available from the data source object.
onerrorupdate	Fires on a databound object when an error occurs while updating the associated data in the data source object.
onfilterchange	Fires when a visual filter changes state or completes a transition.
onlayoutcomplete	Fires when the print or print preview layout process finishes filling the current LayoutRect object with content from the source document.
onmouseenter	Fires when the user moves the mouse pointer into the object.
onmouseleave	Fires when the user moves the mouse pointer outside the boundaries of the object.
onreadystatechange	Fires when the state of the object has changed.
onresize	Fires when the size of the object is about to change.
onrowenter	Fires to indicate that the current row has changed in the data source and new data values are available on the object.
onrowexit	Fires just before the data source control changes the current row in the object.
onrowsdelete	Fires when rows are about to be deleted from the recordset.
onrowsinserted	Fires just after new rows are inserted in the current recordset.
onscroll	Fires when the user repositions the scroll box in the scroll bar on the object.

Methods

Method	Description
addBehavior	Attaches a behavior to the element.
applyElement	Makes the element either a child or parent of another element.
attachEvent	Binds the specified function to an event, so that the function gets called whenever the event fires on the object.
clearAttributes	Removes all attributes and values from the object.
cloneNode	Copies a reference to the object from the document hierarchy.
componentFromPoint	Returns the component located at the specified coordinates via certain events.
contains	Checks whether the given element is contained within the object.
detachEvent	Unbinds the specified function from the event, so that the function stops receiving notifications when the event fires.
doScroll	Simulates a click on a scroll bar component.
fireEvent	Fires a specified event on the object.
getAdjacentText	Returns the adjacent text string.
getAttribute	Retrieves the value of the specified attribute.
getAttributeNode	Retrieves an attribute object referenced by the attribute.name property.
getBoundingClientRect	Retrieves an object that specifies the bounds of a collection of TextRectangle objects.
getClientRects	Retrieves a collection of rectangles that describes the layout of the contents of an object or range within the client. Each rectangle describes a single line.
getElementsByTagName	Retrieves a collection of objects based on the specified element name.
hasAttribute	Determines whether an attribute with the specified name exists.
hasChildNodes	Returns a value that indicates whether the object has children.
insertAdjacentElement	Inserts an element at the specified location.
mergeAttributes	Copies all read/write attributes to the specified element.
normalize	Merges adjacent TextNode objects to produce a normalized document object model.
removeAttribute	Removes an attribute from an object.
removeAttributeNode	Removes an attribute object from the object.
removeBehavior	Detaches a behavior from the element.
replaceAdjacentText	Replaces the text adjacent to the element.
setAttribute	Sets the value of the specified attribute.
setAttributeNode	Sets an attribute object node as part of the object.
swapNode	Exchanges the location of two objects in the document hierarchy.

Prototypes

Object	Description
HTMLBaseElement Constructor	Defines the properties and methods inherited by objects in the HTMLBaseElement Constructor prototype chain.

Styles

Style attribute	Style property	Description
-ms-background-position-x	backgroundPositionX	Sets or retrieves the x-coordinate of the backgroundPosition property.
-ms-background-position-y	backgroundPositionY	Sets or retrieves the y-coordinate of the backgroundPosition property.
-ms-behavior	behavior	Sets or retrieves the location of the Dynamic HTML (DHTML) behavior.
-ms-layout-grid	layoutGrid	Sets or retrieves the composite document grid properties that specify the layout of text characters.
-ms-layout-grid-mode	layoutGridMode	Sets or retrieves whether the text layout grid uses two dimensions.
	pixelBottom	Sets or retrieves the bottom position of the object.
	pixelHeight	Sets or retrieves the height of the object.
	pixelLeft	Sets or retrieves the left position of the object.
	pixelRight	Sets or retrieves the right position of the object.
	pixelTop	Sets or retrieves the top position of the object.
	pixelWidth	Sets or retrieves the width of the object.
	posBottom	Sets or retrieves the bottom position of the object in the units specified by the bottom attribute.
	posHeight	Sets or retrieves the height of the object in the units specified by the height attribute.
	posLeft	Sets or retrieves the left position of the object in the units specified by the left attribute.
	posRight	Sets or retrieves the right position of the object in the units specified by the right attribute.
	posTop	Sets or retrieves the top position of the object in the units specified by the top attribute.
	posWidth	Sets or retrieves the width of the object in the units specified by the width attribute.
-ms-text-autospace	textAutospace	Sets or retrieves the autospacing and narrow space width adjustment of text.
-ms-text-underline-position	textUnderlinePosition	Sets or retrieves the position of the underline decoration that is set through the textDecoration property of the object.

Remarks

  Internet Explorer 8 and later. When read, the value of the href attribute depends on the current document compatibility mode. In addition, relative URL's are no longer supported by the base element.

When used, the base element must appear within the head of the document, before any elements that refer to an external source.

Note   Versions of Internet Explorer prior to Internet Explorer 7 would allow the base element to appear anywhere in the document tree, which caused relative paths to use the "nearest" base element as the base for the URL. Internet Explorer 7 strictly enforces the use of the base tag within the head of the document, and will ignore misplaced tags.

If more than one base element occurs, only the first element will be recognized.

This element is not rendered.

This element does not require a closing tag.

Examples

This example sets the base URL of the document to a reference folder. Internet Explorer uses the base element to resolve the link to http://msdn.microsoft.com/workshop/author/dhtml/reference/properties/href_2.asp.

<html>
<head>
  <base href="http://msdn.microsoft.com/workshop/author/dhtml/reference/"/>
</head>

<body>
Click <a href="properties/href_2.asp">here</a> to learn about the 
href property.
</body>
</html>

This example retrieves the base URL from the document if a valid base element is specified in the document. Otherwise, the function returns null.

<script>
function GetBase()
{
    var oBaseColl = document.all.tags('BASE');
    return ( (oBaseColl && oBaseColl.length) ? oBaseColl[0].href : 
        null );
}
</script>

Standards Information

This object is defined in HTML 3.2 .