DOMUserData - Web APIs 编辑

Deprecated

This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

DOMUserData refers to application data. In JavaScript, it maps directly to Object. It is returned or used as an argument by Node.setUserData(), Node.getUserData(), used as the third argument to handle() on UserDataHandler, and is used or returned by various DOMConfiguration methods.

Note that although it can be an object, in Mozilla, it may be returned as a string or other type, if it was set as such a type (e.g., Node.setUserData() and Node.getUserData()).

DOMUserData is not persisted nor serialized and will not be present after the application has restarted or after a crash. If you are interested in persisting data you might rather need to use nsISessionStore.

Specifications

See also

• Other obsolete APIs for userData: UserDataHandler, node.getUserData, node.setUserData
• Using data attributes is the modern alternative (see data-* attributes, HTMLElement.dataset)
• nsISessionStore