Angular2 Lamp Service Code

lampservice.ts

import { Http, Headers, ConnectionBackend, BaseRequestOptions, Response, ResponseOptions } from '@angular/http';
import { Observable } from 'rxjs';
import { Injectable, Inject } from '@angular/core';

export class Lamp{
    public name : string;
    public address : string;
    public deviceClass : string;
    public type : string;
    public bright : string;
    public isDimmer : boolean;
    public color : string;
}

@Injectable()
export class LampsService {
    private headers = new Headers();
    private http : Http;
    public baseUrl:string;
    public responsive : string;
    public myDoc : Document;

    constructor(@Inject(Http) httpService) {
        this.http = httpService;
        this.baseUrl = this.getRemoteHost();
    }

    // do this to support 192.168.0.92 for testing but allow that or lamps.home for production
    // and then we can use DNS mapping to support lamps.home
    getRemoteHost() : string
    {
        var x = location.hostname;
        // this lets us debug on a local machine (and use hardcoded IP) while on the PI it uses the location.hostname
        if( x == 'localhost')
        {
            x = "192.168.0.92";
        }
        return "http://" + x;
    }

    // this parses the entire device list and creates a list of lamps rather slowly
    parseAllDevices(deviceList : string) : Lamp[]
    {
        var parser = new DOMParser();
        this.myDoc = parser.parseFromString(deviceList, "text/xml");
        var children : NodeList = this.myDoc.childNodes[0].childNodes;
        var len = children.length;
        var theList : Lamp[] = [];
        for(var i = 0; i<len; i++)
        {
            var kid : Node = children.item(i);
            // the first one is named 'root' and the rest are named 'node'
            if(kid.nodeName == 'node')
            {
                var subKids : NodeList = kid.childNodes;
                var kidLen = subKids.length;
                var newLamp = new Lamp();

                // if it has an attribute nodeDefId="DimmerLampSwitch" then it is a Dimmer Switch
                var attribs : NamedNodeMap = kid.attributes;
                var theId : Attr = attribs.getNamedItem('nodeDefId');
                newLamp.isDimmer = false;
                if(theId == null || !(theId.value.startsWith("DimmerLamp") || theId.value.startsWith("RelayLamp")))
                {
                    // don't take anything but lamps
                    continue;
                }
                if(theId != null && (theId.value == "DimmerLampSwitch" || theId.value == "DimmerLampSwitch_ADV"))
                {
                    newLamp.isDimmer = true;
                }

                // walk through the various properties of the lamp
                for(var j = 0; j<kidLen; j++)
                {
                    var subChild = subKids.item(j);
                    switch(subChild.nodeName)
                    {
                        case 'name' :
                            newLamp.name = subChild.textContent;
                            break;
                        case 'address' :
                            newLamp.address = subChild.textContent;
                            break;
                        case 'deviceClass' :
                            newLamp.deviceClass = subChild.textContent;
                            break;
                        case 'type' :
                            newLamp.type = subChild.textContent;
                            break;
                        // property contains a bunch of attributes of which we want the value attribute
                        case 'property' :
                            var attrib : Attr = subChild.attributes.getNamedItem('value');
                            if(attrib != null)
                            {
                                newLamp.bright = attrib.value; 
                            }
                            this.setLampColor(newLamp);
                            break;
                    }
                    //console.log(subChild.nodeName);
                }
                theList.push(newLamp);
            }
        }
        return theList.sort( (a : Lamp, b : Lamp) => { 
                if (a.name > b.name) {
                    return 1;
                }
                return -1;
            });
    }

    addCredentials() : Headers
    {
        // Authentication is done by nginx on the proxy system
        //  var username = "admin";
        //  var password = "password for isy system";
        var headers = new Headers();
      //  headers.append('Authorization', 'Basic ' + btoa(username + ':' + password));
        return headers;
    }

    setLampColor(lamp: Lamp)
    {
       lamp.color =  (lamp.bright != "0") ? "red" : "green";
    }

    getAllpages() : Observable<Response> {
        var myheaders : Headers = this.addCredentials();
        return this.http.get(this.baseUrl + '/rest/nodes/devices', {headers : myheaders}).catch(this.handleError);
    }

    handleError(error: any) {
        console.error(error);
        return Observable.throw(error.json().error || 'Server error');
    }

    turnOnLamp(lamp: Lamp) : Observable<Response>
    {
        var nodeId : string = encodeURIComponent(lamp.address);
        var pathAll : string = "/rest/nodes/" + nodeId + "/cmd/DON";
        var myheaders : Headers = this.addCredentials();
        lamp.bright = "255";
        this.setLampColor(lamp);
        return this.http.get(this.baseUrl + pathAll, {headers : myheaders}).catch(this.handleError);
    }

    turnOffLamp(lamp : Lamp) : Observable<Response>
    {
        var myheaders : Headers = this.addCredentials();
        var nodeId : string = encodeURIComponent(lamp.address);
        var pathAll : string = "/rest/nodes/" + nodeId + "/cmd/DOF";
        lamp.bright = "0";
        this.setLampColor(lamp);
        return this.http.get(this.baseUrl + pathAll, {headers : myheaders}).catch(this.handleError);
    }

    setBrightness(lamp : Lamp, brightness : number) : Observable<Response>
    {
        var myheaders : Headers = this.addCredentials();
        var nodeId : string = encodeURIComponent(lamp.address);
        var pathAll : string = "/rest/nodes/" + nodeId + "/cmd/DON/" + brightness;
        this.setLampColor(lamp);
        return this.http.get(this.baseUrl + pathAll, {headers : myheaders}).catch(this.handleError);
    }
}