Learning Angular for .NET Developers

Calling the PUT action of the Web API to update a Todo item

We just added code to consume the Web API GET action and also added code to POST a new Todo item to the Web API. Now, let's consume the PUT action in the Web API to update an existing Todo item. Follow these steps to do so:

1. Open todo.service.ts.
2. Add the putTodo function with the following code snippet to update the existing Todo item by calling the PUT action in the Web API:

     putTodo(todo: Todo) {       var headers = new Headers();        headers.append('Content-Type', 'application/json');        this.http.put('/api/todos/' + todo.id,       JSON.stringify(todo), { headers: headers })             .toPromise()             .then(() => todo)             .catch(this.handleError);      } 

This code defines the header with the JSON content type ...