In this how-to tutorial
, we'll learn what is the HttpClient
API available from HttpClientModule
and how to use it in Angular 9 by example with request timeout, responsetype, query parameters, http headers, interceptors, typed and full responses, and error handling.
Also check out:
- Build an Angular 9/8 CRUD Example & Tutorial
- Angular 9 Tutorial and Example: Build your First Angular App
We'll be seeing examples of common HTTP methods such as GET, PUT, PATCH, POST and DELETE, that you usually need to use when communicating with a server, or consuming and fetching data from a REST API server.
We'll be learning about:
- Accessing Http Headers,
- Passing Http Parameters,
- Specifying HttpClient ResponseType i.e Text, JSON or Blob,
- Setting up HttpClient Interceptors,
- Implementing Http Error Handling,
- Dealing with Browser CORS and the Same Origin Policy
This tutorial is divided in the following parts:
- Importing
HttpClient
and sending Http get, post, put and delete requests to the server (this part), - Building a service to encapsulate the
HttpClient
code interfacing with the server, - Getting headers and typed and full responses with Angular HttpClient,
- Uploading files with Angular
HttpClient
- Communicating with a Node.js & Express server using POST Requests
- Using the async pipe for sending GET requests,
- Handling CORS and the Same Origin Policy in modern web browsers
Also read:
Angular 7|6 Tutorial: Using Angular HttpClient with Node & Express.js - Example POST Requests
Angular 7|6 By Example: HTTP GET Requests with HttpClient (Services, async pipe and Observables)
npm install -g json-server
json-server --watch db.json
Run ng serve
for a dev server. Navigate to http://localhost:4200/
. The app will automatically reload if you change any of the source files.