Angular 6 Post Request to .NET Core API

To make a post request in Angular 6 with standard practice you need to do followings:

In the service class:

import {throwError,  Observable } from 'rxjs';
import {catchError} from 'rxjs/operators';
import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders, HttpParams, HttpErrorResponse } from '@angular/common/http';
import { Rule } from 'path';

@Injectable()
export class RuleService {
    constructor(private httpClient: HttpClient) { }
    private baseUrl = window.location.origin + '/api/Rule/';

    createTemplateTextRules(rules: Rules[]): Observable<boolean> {
       const body = JSON.stringify(rules);
       const headerOptions = new HttpHeaders({ 'Content-Type': 'application/json' });
       return this.httpClient.post<boolean>(this.baseUrl + 'AddTemplateTextRules', body, {
              headers: headerOptions
       }).pipe(catchError(this.handleError.bind(this));
    }

   handleError(errorResponse: HttpErrorResponse) {
     if (errorResponse.error instanceof ErrorEvent) {
        console.error('Client Side Error :', errorResponse.error.message);
     } else {
       console.error('Server Side Error :', errorResponse);
     }

    // return an observable with a meaningful error message to the end user
    return throwError('There is a problem with the service.We are notified & 
     working on it.Please try again later.');
   }
}

In the Component:

export class RuleComponent implements OnInit { 
    constructor(private ruleService: RuleService) { }
    createTemplateTextRules(): void {

    this.ruleService.createTemplateTextRules(rules).subscribe((creationStatus) => {
      // Do necessary staff with creation status
     }, (error) => {
      // Handle the error here
     });
   }
}

Then in the ASP.NET Core API Controller:

[Produces("application/json")]
[Route("api/Rule/[action]")]
public class RuleController : Controller
{
   [HttpPost]
   public Task<IActionResult> AddTemplateTextRules( [FromBody]Rule[] Rules)
   {
       try
       {
           return RuleManager.AddRule(Rules);
       }
       catch (Exception e)
       {
            return false;
       }
       return Json(true);
   }
}

Hope it will help you.

With the latest RxJS(Angular 14) here is the way:

Service

  Login(phone:string,password:string)
  {
    let _headers: HttpHeaders = new HttpHeaders({
      'accept': 'application/json'
    });
    return this.http.post(this.url,{username,password},{headers:_headers})
                .pipe(map(response=>response));
  }

Component

  async Login(phone:string,password:string)
  {
    let token$ =  this.authService.Login(phone,password);
    let token = await lastValueFrom(token$);
  }

Since I was returning just text and not Json from the API, this was my code to handle text response type in the Service. If you're getting a response parse error, explicitly defining the responseType will help since Json is default.

  Login(phone:string,password:string)
  {
    let _headers: HttpHeaders = new HttpHeaders({
      'accept': 'text/plain'
    });
    return this.http.post(this.url+'security/login?phone='+phone+'&password='+password,null,{headers:_headers,responseType:'text'})
                .pipe(map(response=>response));
  }