delta-listener

delta-listener

Deeply compare JavaScript objects and listen to changes. Used in colyseus.js v0.6.0+.

Usage

import { DeltaContainer } from "delta-listener"
let container = new DeltaContainer({
    entities: {
        one: { x: 10, y: 10 },
        two: { x: 10, y: 10 }
    }
});

container.listen("entities/:id", "add", (entityId: string, value: any) => {
    console.log("new entity", entityId, value);
})

container.set({
    entities: {
        one: { x: 20, y: 10 },
        two: { x: 10, y: 10 }
    }
})

See tests for more usage examples.

Built-in placeholders

• :id: /([a-zA-Z0-9\-_]+)/
• :number: /([0-9]+)/
• :string: /(\w+)/
• *: /(.*)/

When any other name is used starting with : (e.g. :example), * will be used instead.

Example:

container.listen("players/:entityId", "replace", (entityId: string, value: any) => {
    console.log(key, "changed to", value);
})

Is equivalent to:

container.listen("players/*", "replace", (entityId: string, value: any) => {
    console.log(key, "changed to", value);
})

Special thanks

The compare method is highly based on fast-json-patch implementation.

License

MIT