Object.unobserve()
Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
The Object.unobserve()
method was used to remove observers set by Object.observe()
, but has been deprecated and removed from Browsers. You can use the more general Proxy
object instead.
Syntax
Object.unobserve(<var>obj</var>, <var>callback</var>)
Parameters
obj
- The object to stop observing.
callback
- The reference to the observer to stop calling each time changes are made on the object obj.
Return value
The specified object.
Description
Object.unobserve()
should be called after Object.observe()
in order to remove an observer from an object.
The callback should be a reference to a function and not an anonymous function, because this reference will be used to unset the previous observer. It's useless to call Object.unobserve() with an anonymous function as callback, it will not remove any observer.
Examples
Unobserving an object
var obj = { foo: 0, bar: 1 }; var observer = function(changes) { console.log(changes); } Object.observe(obj, observer); obj.newProperty = 2; // [{name: 'newProperty', object: <obj>, type: 'add'}] Object.unobserve(obj, observer); obj.foo = 1; // The callback wasn't called
Using an anonymous function
var person = { name : 'Ahmed', age : 25 }; Object.observe(person, function (changes) { console.log(changes); }); person.age = 40; // [{name: 'age', object: <obj>, oldValue: 25, type: 'update'}] Object.unobserve(person, function (changes) { console.log(changes); }); person.age = 63; // [{name: 'age', object: <obj>, oldValue: 40, type: 'update'}] // The callback will always be called
Specifications
Strawman proposal specification.
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 36 | No support | No support | 23 | No support |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | No support | 36 | No support | No support | 23 | No support |
See also
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/object/unobserve