39699 2010-05-25 16:36:08 -0700 Implement DOM Level 3 Node::getUserData/setUserData 2023-08-26 01:08:50 -0700 1 1 1 Unclassified WebKit DOM 528+ (Nightly build) All All RESOLVED INVALID P2 Normal --- 1 kangax webkit-unassigned annevk ap bugzilla+webkit cdumez john.david.dalton oliver sam oldest_to_newest 230523 0 kangax 2010-05-25 16:36:08 -0700 DOM Level 3 is currently draft, but `Node::getUserData` (http://www.w3.org/TR/DOM-Level-3-Core/core.html#Node3-getUserData )/`Node::setUserData` (http://www.w3.org/TR/DOM-Level-3-Core/core.html#Node3-setUserData ) are already implemented in Mozilla and are a convenient way to store user data for node (instead of assigning expandos). 307929 1 sam 2010-11-11 08:05:51 -0800 How does using userData differ from using expandos? Why would one want to use use it rather than an expando? 307937 2 kangax 2010-11-11 08:22:08 -0800 The problem with expandos is collisions with members of any interfaces implemented by a node in question. How can you have a data under a key of "nodeName", "appendChild", etc. In implementations that make DOM objects inherit from Object.prototype or Function.prototype (such as webkit) there's additional set of candidates for collisions (toString, constructor, call, etc.). 307945 3 annevk 2010-11-11 08:31:41 -0800 If the problem is collisions we should do something much simpler than UserData imo. (Note that UserData is tentatively removed from Web DOM Core.) 307952 4 kangax 2010-11-11 08:59:00 -0800 (In reply to comment #3) > If the problem is collisions we should do something much simpler than UserData imo. (Note that UserData is tentatively removed from Web DOM Core.) Ok. But simpler how? I can imagine something like `Node::userData` (shorter name + no function call) where `userData` would need to be explicitly specified to have [[Prototype]] of null. Or did you mean something else? 307965 5 john.david.dalton 2010-11-11 09:31:53 -0800 I know there are also issues with expando's and cloneNode() in IE (IE copies non-object value expandos to the clone, and also issues with some Java Applets barfing when devs attempt to set expando's on them. 1503000 6 lforschler 2019-02-06 09:03:36 -0800 Mass moving XML DOM bugs to the "DOM" Component. 1973758 7 annevk 2023-08-26 01:08:50 -0700 This feature is no longer standardized. The alternative is using WeakMap.