无法从angular2服务使用外部webapi服务 [英] Not able to consume external webapi service from angular2 service
问题描述
我的要求是创建一个angular2组件，该组件将使用外部WebAPI服务并根据接收到的数据生成气泡图. 我创建了一个Dataservice组件，该组件将发出http get请求.数据服务的代码如下
My requirement is to create a angular2 component which would consume the external WebAPI service and generate a bubblechart based on the data received. I have created a Dataservice component which would make the http get request. the code for Dataservice is below
import { Injectable } from 'angular2/core';
import { HTTP_PROVIDERS, Http, Headers, Response, JSONP_PROVIDERS, Jsonp } from 'angular2/http';
import { Configuration } from './Configuration';
import 'rxjs/add/operator/map'
import { Observable } from 'rxjs/Observable';
///Service class to call REST API
@Injectable()
export class DataService {
private DataServerActionUrl: string;
private headers: Headers;
result: Object;
constructor(private _http: Http, private _configuration: Configuration) {
this.DataServerActionUrl = "http://localhost:23647/api/extractorqueue/getextractorqueueslatest/";
this.headers = new Headers();
this.headers.append('content-type', 'application/json');
this.headers.append('accept', 'application/json');
}
public GetExtractorQueuesLatest() {
return this._http.get(this.DataServerActionUrl)
.map(response => response.json())
.subscribe((res) => {
this.result = res;
console.log(this.result);
},
(err) => console.log(err),
() => console.log("Done")
);
}
创建气泡图组件的代码如下:尝试获取GetExtractorQueuesLatest()方法返回的数据时遇到问题.
The code for creating the bubblechart component is below: I am facing issues while trying to fetch the data returned by the GetExtractorQueuesLatest() method.
import { HTTP_PROVIDERS, Http, Headers, Response, JSONP_PROVIDERS, Jsonp } from 'angular2/http';
import { Component, OnInit } from 'angular2/core';
import { CORE_DIRECTIVES } from 'angular2/common';
import { DataService } from '../DataService';
declare var d3: any;
@Component({
//selector: 'bubble-chart',
styles: [``],
directives: [CORE_DIRECTIVES],
providers: [DataService],
//template: ``
templateUrl:'bubblechart.html'
})
export class BubbleChartComponent implements OnInit {
public resultData: any;
_http: Http;
private headers: Headers;
constructor(private _dataService: DataService) { }
ngOnInit() {
this._dataService
.GetExtractorQueuesLatest().subscribe(res => this.resultData = res);
error => console.log(error),
() => console.log('Extractor Queues Latest'));
this.DrawBubbleChart();
}
margin = 25;
diameter = 915;
color = d3.scale.linear()
.domain([-1, 5])
.range(["hsl(152,80%,80%)", "hsl(228,30%,40%)"])
.interpolate(d3.interpolateHcl);
pack = d3.layout.pack()
.padding(2)
.size([this.diameter - this.margin, this.diameter - this.margin])
.value(function (d) { return d.size; })
svg = d3.select("router-outlet").append("svg")
.attr("width", this.diameter)
.attr("height", this.diameter)
.append("g")
.attr("transform", "translate(" + this.diameter / 2 + "," + this.diameter / 2 + ")");
private DrawBubbleChart(): void {
var chart = d3.json(this.resultData, (error, root) => {
if (error) throw error;
var focus = root,
nodes = this.pack.nodes(root),
view;
var circle = this.svg.selectAll("circle")
.data(nodes)
.enter().append("circle")
.attr("class", function (d) { return d.parent ? d.children ? "node" : "node node--leaf" : "node node--root"; })
.style("fill", (d) => { return d.children ? this.color(d.depth) : null; })
.on("click", (d) => { if (focus !== d) zoom.call(this, d), d3.event.stopPropagation(); });
var text = this.svg.selectAll("text")
.data(nodes)
.enter().append("text")
.attr("class", "label")
.style("fill-opacity", function (d) { return d.parent === root ? 1 : 0; })
.style("display", function (d) { return d.parent === root ? "inline" : "none"; })
.text(function (d) { return d.name; });
var node = this.svg.selectAll("circle,text");
d3.select("router-outlet")
.style("background", this.color(-1))
.on("click", () => { zoom.call(this, root); });
zoomTo.call(this, [root.x, root.y, root.r * 2 + this.margin]);
function zoom(d) {
var focus0 = focus; focus = d;
var transition = d3.transition()
.duration(d3.event.altKey ? 7500 : 750)
.tween("zoom", (d) => {
var i = d3.interpolateZoom(view, [focus.x, focus.y, focus.r * 2 + this.margin]);
return (t) => { zoomTo.call(this, i(t)); };
});
transition.selectAll("text")
.filter(function (d) { return d.parent === focus || this.style.display === "inline"; })
.style("fill-opacity", function (d) { return d.parent === focus ? 1 : 0; })
.each("start", function (d) { if (d.parent === focus) this.style.display = "inline"; })
.each("end", function (d) { if (d.parent !== focus) this.style.display = "none"; });
}
function zoomTo(v) {
var k = this.diameter / v[2]; view = v;
node.attr("transform", function (d) { return "translate(" + (d.x - v[0]) * k + "," + (d.y - v[1]) * k + ")"; });
circle.attr("r", function (d) { return d.r * k; });
}
});
}
}
我面临的问题是未调用外部webapi服务方法.我不确定代码中在这里犯了什么错误，任何人都可以指导我并纠正错误吗?
the Problem I am facing is the external webapi service method is not being called. I am not sure what is the mistake I have done here in the code, can any one please guide me on this and correct the mistakes?
推荐答案
您已经预订了GetExtractorQueuesLatest()方法.您可能应该重写它，以仅返回Observable并订阅组件的ngOnInit().
You're already subscribing in your GetExtractorQueuesLatest() method. You probably should rewrite it to just return an Observable and subscribe in the ngOnInit() of your component.
另外，我认为您应该将this.DrawBubbleChart()调用移到subscribe lambda函数中，这样不会太早被调用.
Also I think you should move the this.DrawBubbleChart() call into the subscribe lambda function, so it doesn't get called too early.
为您服务:
public GetExtractorQueuesLatest() {
return this._http.get(this.DataServerActionUrl)
.map(response => response.json());
}
在您的组件中:
ngOnInit() {
this._dataService.GetExtractorQueuesLatest()
.subscribe(
(res) => {
this.resultData = res;
this.DrawBubbleChart();
},
(error) => console.log(error),
() => console.log('Extractor Queues Latest')
);
}
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