Error message: Unable to access property 'post' from undefined - Angular 2

Here is the snippet of code in my component file:

import { Component, Injectable, Inject, OnInit, OnDestroy, EventEmitter, Output } from '@angular/core';
import { Http, Response, Headers, RequestOptions } from '@angular/http';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/toPromise';
import 'rxjs/add/operator/switchMap';
...
@Injectable()
export class MyComponent {
    constructor(private http: Http) {}
    saveDetails() {
        var response: any;
        var body = customer_details;
        var headers = new Headers({ 'Content-Type': 'application/json' });
        var options = new RequestOptions({ headers: headers });
        this.http.post("/user/add-customer-details", body, options)
            .map((res:Response) => res.json()).subscribe(
                data => { response = data },
                err => console.error(err),
                () => {
                    console.log(response);
                }
            );
    }
}

Despite no compilation error or any other issue, when invoking the post method, I encounter an error stating

Cannot read property 'post' of undefined
. To troubleshoot, I inserted console.log(this.http); just before the post method call and found it to be displaying undefined in the browser console. Even after attempting various solutions, I am unable to ascertain why it isn't functioning correctly. Any assistance would be greatly appreciated.

Many thanks for your help!

Answer №1

After spending countless hours scratching my head and scouring the depths of the internet for answers, I have finally discovered the solution.

The breakthrough came when I made a simple change to my constructor code:

constructor (@Inject(Http) private http:Http) { }

Previously, it was just:

constructor (private http: Http) { }

Despite the experimental nature of the @Inject decorator, it proved to be the key to resolving my issue.

I am grateful to everyone who contributed to this problem-solving journey... Thank you all.

Answer №2

Make sure to include HTTP_PROVIDERS in the component providers array as shown below:

providers: [HTTP_PROVIDERS]

UPDATE

It's important to note that HTTP_PROVIDERS is no longer supported. Please import the http module instead.

@NgModule({
    imports: [
        BrowserModule,
        HttpModule  
        ],
    declarations: [AppComponent],
    providers: [],
    bootstrap: [AppComponent],
})

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