无法从角度http检索数据 [英] cannot retrieve data from angular http
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问题描述
我正在尝试使用下面的代码使用http模块从mongodb中的集合中检索数据,
I'm trying to retrieve data from a collection in my mongodb using http module using the code below,
getPosts() {
return this.http.get('http://localhost:5005/blog/getposts').map(res => {
console.log("mapped result",res);
res.json()
});
}
每次都失败并返回响应
Unexpected token < in JSON at position 0
at JSON.parse (<anonymous>)
at Response.webpackJsonp.../../../http/@angular/http.es5.js.Body.json (http.es5.js:797)
at MapSubscriber.project (auth.service.ts:45)
at MapSubscriber.webpackJsonp.../../../../rxjs/operators/map.js.MapSubscriber._next (map.js:79)
at MapSubscriber.webpackJsonp.../../../../rxjs/Subscriber.js.Subscriber.next (Subscriber.js:89)
at XMLHttpRequest.onLoad (http.es5.js:1226)
at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invokeTask (zone.js:425)
at Object.onInvokeTask (core.es5.js:3881)
at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invokeTask (zone.js:424)
at Zone.webpackJsonp.../../../../zone.js/dist/zone.js.Zone.runTask (zone.js:192)
但是当我和邮递员一起尝试时,我得到的是预期的结果,
but when I try it with postman, I'm getting the expected result which is this,
我要从服务中返回响应,并从这样的组件中订阅其数据,
I'm returning the response from the service and subscribing its data from a component like this,
ngOnInit() {
this.auth.getPosts().subscribe(data => {
this.value = data.posts;
console.log("blog component",this.value)
},err => {
console.log(err);
})
}
我做错了什么?任何帮助将不胜感激
What am I doing wrong? Any help would be much appreciated
推荐答案
尝试在.map()
getPosts() {
return this.http.get('http://localhost:5005/blog/getposts').map(res => {
console.log("mapped result",res);
return res.json()
});
}
}
或删除方括号(这将给您带来隐含的回报),
or drop the brackets (this gives you an implied return),
getPosts() {
return this.http.get('http://localhost:5005/blog/getposts')
.map(res => res.json() );
}
}
这篇关于无法从角度http检索数据的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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