XML DOM hasFeature() method
Definition and usage
The hasFeature() method determines whether the DOM implementation supports a certain feature.
Syntax:
nodeObject.selectNodes(feature, version)
| Parameter | Description |
|---|---|
| feature |
Feature name, used to determine which support is being tested. Features are case-insensitive. The following table lists the set of valid feature names supported by the 2nd level DOM standard. |
| version |
Version number, used to determine which support is being tested, or null. If all versions of the feature are supported, it is an empty string (" "). In the 2nd level DOM standard, the supported version numbers are 1.0 and 2.0. |
Return value
If the current implementation fully supports the specified version of the specified feature, the return value is true, otherwise false. If the version number is not specified and the implementation fully supports all versions of the specified feature, the method also returns true.
Explaination
The W3C DOM standard is modular and does not require each implementation to implement all modules or features in the standard. This method is used to detect whether a DOM implementation supports the specified module of the DOM standard.
Note that although Internet Explorer 5 and 5.5 partially support the 1st level DOM standard, before IE 6, there was no implementation that supported this important method.
The following table lists the complete set of module names that can be used as the feature parameter.
| Features | Description |
|---|---|
| Core |
The basic interfaces that all DOM implementations, such as Node, Element, Document, Text, and others, are required to implement All implementations that comply with the DOM standard must support this module. |
| HTML | Implement HTMLElement, HTMLDocument, and other HTML-specific interfaces. |
| XML | Implement Entity, EntityReference, ProcessingInstruction, Notation, and other node types specific to XML documents. |
| StyleSheets | Implement the simple interface for describing ordinary style sheets. |
| CSS | Implement the interface for CSS style sheets. |
| CSS2 | Implement the CSS2Properties interface. |
| Events | Implement the basic event handling interface. |
| UIEvents | Implement the interface for handling user interface events. |
| MouseEvents | Implement the interface for handling mouse events. |
| HTMLEvents | Implement the interface for handling HTML events. |
| MutationEvents | Implement the interface for handling document change events. |
| Range | Implement the interface for operating document ranges. |
| Traversal | Implement the interface for advanced document traversal. |
| Views | Implement the interface for handling document views. |
