How do I actually apply a diff "later"?

[Pomax]

I can't seem to figure out how to apply a diff generated by the diff function if all I have is a target and a change object. For instance, in a client/server setup:

atServer() {
    let patch = diff(prevState, newState);
    client.sendPatch(patch);
}

and

client.onPatch(patch) {
    let patched = applyDiff(this.state, patch); // <- what is this call?
    this.processUpdatedState(patched);
}

What is the call to actually apply a diff to an object? Not "while generating the diff" using applyChange, and not "while having a direct reference to the original object" because then what's the point of diffing at all (you already have the result).

There's an applyDiff function but its signature is applyDiff(target, source, filter) which makes no sense: is source supposed to be the diff object?

[emmanuelgomez]

@Pomax I had the same problem and after a lot of work I found a way to do it with this package. The examples of this repo explain how to implement it. Greetings.

diff/examples/capture_change_apply_elsewhere.js

Lines 24 to 30 in e2b5b86

	// record the differences between source and comparand
	var changes = diff(source, comparand);
	// apply the changes to the source
	changes.forEach(function (change) {
	diff.applyChange(source, true, change);
	});

I can't seem to figure out how to apply a diff generated by the diff function if all I have is a target and a change object. For instance, in a client/server setup:

atServer() {
    let patch = diff(prevState, newState);
    client.sendPatch(patch);
}

and

client.onPatch(patch) {
    let patched = applyDiff(this.state, patch); // <- what is this call?
    this.processUpdatedState(patched);
}

What is the call to actually apply a diff to an object? Not "while generating the diff" using applyChange, and not "while having a direct reference to the original object" because then what's the point of diffing at all (you already have the result).

There's an applyDiff function but its signature is applyDiff(target, source, filter) which makes no sense: is source supposed to be the diff object?

[Pomax]

I went the other way and am now using rfc6902 for the creating of diffs (server side), and jsonpatch to apply them (client side).