object-mutation-observer
v2.0.5
Published
```JavaScript const linked = { link: 'a', obj: {} } const obj = { "1": 2, a: "b", linked1: linked, linked2: linked, nested: { c: "c" }, recursive: { obj: this
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Quickstart
const linked = {
link: 'a',
obj: {}
}
const obj = {
"1": 2,
a: "b",
linked1: linked,
linked2: linked,
nested: {
c: "c"
},
recursive: { obj: this },
array: [2, 4, 3, 5, 1, 6],
sorted: [1, 2, 3, 4, 5, 6],
[Symbol()]: {
symbol: {
bool: true
},
linked
}
};
obj.recursive = { obj };
const observer = new ObjectMutationObserver({ emit: 'async', resolveChangeAncestors: 'early' }));
const proxy = observer.watch(obj);
observer.watch(proxy, v=> console.log(v));
proxy.f = 'b';
// console:
// {
// event: 'change', // Type of event
// type: 'set', // Subtype of event
// target: proxy, // The object that had changes on it
// key: 'f', // The property that was modfied
// previous: undefined, // The previous value
// current: 'b', // The new value
// reference: proxy, // The object the listener was attached to
// paths: ["/f", "/recursive/obj/f"] // The paths relative to the listened to object
// }
Goals
- Must not leak implementation code into the original objects
- Must allow multiple listeners
- Must allow attaching listeners at any time and at any level by passing the object to listen to
- Must not prevent garbage collection of objects
- Should capture all mutations
- Should be indistinguishable from original object. No Code Changes required ie
obj.a = '1'
must not need to be changed toset(obj.a, '1')
* Exception for optional wrapping methods to tag execution started/ended ie Array.sort started/ended - Should work with all objects and keys including functions and symbols
- Should work with recursive objects and objects with multiple ancestors
- Should resolve all paths relative to change