Watch an object or array for changes
It works recursively, so it will even detect if you modify a deep property like obj.a.b[0].c = true
.
Uses the Proxy
API.
$ npm install on-change
const onChange = require('on-change');
const object = {
foo: false,
a: {
b: [
{
c: false
}
]
}
};
let i = 0;
const watchedObject = onChange(object, () => {
console.log('Object changed:', ++i);
});
watchedObject.foo = true;
//=> 'Object changed: 1'
watchedObject.a.b[0].c = true;
//=> 'Object changed: 2'
Returns a version of object
that is watched. It's the exact same object, just with some Proxy
traps.
Type: Object
Object to watch for changes.
Type: Function
Function that gets called anytime the object changes.
I had some code that was like:
const foo = {
a: 0,
b: 0
};
// …
foo.a = 3;
save(foo);
// …
foo.b = 7;
save(foo);
// …
foo.a = 10;
save(foo);
Now it can be simplified to:
const foo = onChange({
a: 0,
b: 0
}, () => save(foo));
// …
foo.a = 3;
// …
foo.b = 7;
// …
foo.a = 10;
- known - Allow only access to known object properties (Uses
Proxy
too) - negative-array - Negative array index support
array[-1]
(UsesProxy
too) - statux - State manager (Uses
Proxy
too) - introspected - Never-ending Proxy with multiple observers (Uses
Proxy
too)
MIT © Sindre Sorhus