ui-router-rx.ts

/** @module rx */
/** */
import "rxjs/add/operator/mergeMap";
import "rxjs/add/operator/map";
import { Observable } from "rxjs/Observable";
import { ReplaySubject } from "rxjs/ReplaySubject";
import { Transition, UIRouter, StateDeclaration, UIRouterPlugin } from "@uirouter/core";

export interface StatesChangedEvent {
  currentStates: StateDeclaration[];
  registered: StateDeclaration[];
  deregistered: StateDeclaration[];
}

declare module '@uirouter/core/lib/globals' {
  interface UIRouterGlobals {
    states$?: Observable<StatesChangedEvent>;
    start$?: Observable<Transition>;
    success$?: Observable<Transition>;
    params$?: Observable<{ [paramName: string]: any }>;
  }
}

/** Augments UIRouterGlobals with observables for transition starts, successful transitions, and state parameters */
export class UIRouterRx implements UIRouterPlugin {
  name = 'ui-router-rx';
  private deregisterFns: Function[] = [];

  constructor(router: UIRouter) {
    let start$ = new ReplaySubject<Transition>(1);
    let success$ = <Observable<Transition>> start$.mergeMap((t: Transition) => t.promise.then(() => t));
    let params$ = success$.map((transition: Transition) => transition.params());

    let states$ = new ReplaySubject<StatesChangedEvent>(1);

    function onStatesChangedEvent(event: string, states: StateDeclaration[]) {
      let changeEvent = {
        currentStates: router.stateRegistry.get(),
        registered: [],
        deregistered: []
      };

      if (event) changeEvent[event] = states;
      states$.next(changeEvent);
    }

    this.deregisterFns.push(router.transitionService.onStart({}, transition => start$.next(transition)));
    this.deregisterFns.push(router.stateRegistry.onStatesChanged(onStatesChangedEvent));
    onStatesChangedEvent(null, null);
    Object.assign(router.globals, { start$, success$, params$, states$ });
  }

  dispose() {
    this.deregisterFns.forEach(deregisterFn => deregisterFn());
    this.deregisterFns = [];
  }
}