Observables Ionic 2

//Ionic 2 && Angular RC4

//app.ts
import { Component }      from '@angular/core';
import { HTTP_PROVIDERS } from '@angular/http';

import { Platform, ionicBootstrap } from 'ionic-angular';
import { StatusBar }      from 'ionic-native';

import { TabsPage }       from './pages/tabs/tabs';
import { LoginPage }      from './pages/login/login';

import { DataService }    from './dashboard/data.service'


@Component({
  template: '<ion-nav [root]="rootPage"></ion-nav>',
  providers: [DataService]
})

export class MyApp {
  private rootPage:any;

  constructor(private platform: Platform) {
    var cache_settings = localStorage.getItem('cache_settings');
    if(cache_settings === null){
      localStorage.clear();
      this.rootPage   = LoginPage;
    } else {
      this.rootPage   = TabsPage;
    }

    platform.ready().then(() => {
      // Okay, so the platform is ready and our plugins are available.
      // Here you can do any higher level native things you might need.
      StatusBar.styleDefault();
    });
  }
}

ionicBootstrap(MyApp, [DataService])



//data.service.ts
import { Injectable }                   from '@angular/core';
import { Http }                         from '@angular/http';

import { Observable }                   from 'rxjs/Observable';
import 'rxjs/rx';


//import { App }                        from './../globals';


@Injectable()
export class DataService {
    public data;
    public charts        = {};
    public instances:any = {};

    constructor(public http: Http){}

    fetchData(localData, project_id = null, callback?){
        debugger;
        //TODO: Look up ES6 Features I can use to bypasss this
        window['App'].self = this;

        var cache = window.localStorage.getItem('cache_settings');
            cache = (typeof cache !== 'undefined' && cache == 'true') ? true : false;

        if(localData !== null && typeof localData == 'string' && cache == true) {
            console.log('fetching cached data:');
            this.data = JSON.parse(localData);

        } else {
            var observable = this.http.get('http://www.mysite.com/dash/projects/' + project_id).map( (data) => {
                return data.json();
              }).subscribe(data => {
                console.log('Observable setting data: Project specific data came back with: ', data);

                window.localStorage.setItem('project_data', JSON.stringify(data));
                window['App'].loading.dismiss();

                this.data = data;
                if(typeof callback !== 'undefined') callback();
            });
        }

        return this.data;
    }

    /* Cached project matches project being fetched */
    isCurrentProject(projectId, newProjectId){
        return (projectId === newProjectId);
    }

    studiesDidChange(project_id, data = null){
        var _data   = this.fetchData(window.localStorage.getItem('project_data'), project_id);
        var data    = (data !== null) ? data : _data;

        return (project_id !== data.survey.id);
    }

    shouldStoreData(data, project_id){
        return (this.dataIsValid(data) && this.isCurrentProject(project_id, data.survey.id));
    }

    /* Confirms data from local storage is an acutal response object */
    dataIsValid(data){
        return (typeof data == 'object' && data !== null);
    }

    getData(){
        return this.data;
    }

    getProjectId(data = null){
        return (this.dataIsValid(data)) ? data.id : window.localStorage.getItem('project_id');
    }

    pushChart(chartType, data, chart){
        var chart_id = chartType + '-' + data.survey.id;
        this.charts[chart_id] = chart;
    }

    removeCharts(){
        for(var chartName in this.charts){
            var chart = this.charts[chartName];
            chart.detach();
            chart.container.remove();
        }
    }

    reloadCharts(){
        window['App'].self.instances.Dashboard.initializeDashboard();
    }
}