ultraviolet/client/history.js

import EventEmitter from "./events.js";
import HookEvent from "./hook.js";

class History extends EventEmitter {
    constructor(ctx) {
        super();
        this.ctx = ctx;
        this.window = this.ctx.window;
        this.History = this.window.History;
        this.history = this.window.history;
        this.historyProto = this.History ? this.History.prototype : {};
        this.pushState = this.historyProto.pushState;
        this.replaceState = this.historyProto.replaceState;
        this.go = this.historyProto.go;
        this.back = this.historyProto.back;
        this.forward = this.historyProto.forward;
    };
    override() {
        this.overridePushState();
        this.overrideReplaceState();
        this.overrideGo();
        this.overrideForward();
        this.overrideBack();
    };
    overridePushState() {
        this.ctx.override(this.historyProto, 'pushState', (target, that, args) => {
            if (2 > args.length) return target.apply(that, args);
            let [ state, title, url = '' ] = args;

            const event = new HookEvent({ state, title, url }, target, that);
            this.emit('pushState', event);

            if (event.intercepted) return event.returnValue;
            return event.target.call(event.that, event.data.state, event.data.title, event.data.url);
        });
    };
    overrideReplaceState() {
        this.ctx.override(this.historyProto, 'replaceState', (target, that, args) => {
            if (2 > args.length) return target.apply(that, args);
            let [ state, title, url = '' ] = args;

            const event = new HookEvent({ state, title, url }, target, that);
            this.emit('replaceState', event);

            if (event.intercepted) return event.returnValue;
            return event.target.call(event.that, event.data.state, event.data.title, event.data.url);
        });
    };
    overrideGo() {
        this.ctx.override(this.historyProto, 'go', (target, that, [ delta ]) => {
            const event = new HookEvent({ delta }, target, that);
            this.emit('go', event);

            if (event.intercepted) return event.returnValue;
            return event.target.call(event.that, event.data.delta);
        });
    };
    overrideForward() {
        this.ctx.override(this.historyProto, 'forward', (target, that) => {
            const event = new HookEvent(null, target, that);
            this.emit('forward', event);

            if (event.intercepted) return event.returnValue;
            return event.target.call(event.that);
        });
    };
    overrideBack() {
        this.ctx.override(this.historyProto, 'back', (target, that) => {
            const event = new HookEvent(null, target, that);
            this.emit('back', event);

            if (event.intercepted) return event.returnValue;
            return event.target.call(event.that);
        });
    };
};

export default History;