fnx_rest

Set of REST tools which work nicely with Dart 2 / Angular.

fnx_rest is oriented to be developer and Angular friendly and is particularly useful when creating boring CRUD applications with many similar API calls.

Example

    import 'package:fnx_rest/fnx_rest_browser.dart';
//     import 'package:fnx_rest/fnx_rest_io.dart'; (when not in a browser)       

    RestClient root = BrowserRestClient.root("/api/v1");        
    RestResult response = await root.child("/users").get();
    List users = response.data;

Angular support

You can define root REST client, add your API keys and other additional headers to it and inject this root client with Angular's dependency injection to your elements and/or services.

    RestClient root = BrowserRestClient.root("/api/v1");            
          
    // your component
    class MyApp {
        RestClient restRoot;
        MyApp(this.restRoot);        
    }
    
    // add custom headers, for example after user's signing in
    restRoot.setHeader("Authorization", authKey);       

(see Angular docs for DI details)

RestClient is hierarchical:

    RestClient root = BrowserRestClient.root("/api/v1");   //  /api/v1
    RestClient users = root.child("/users");            //  /api/v1/users            
    RestClient john = users.child("/123");              //  /api/v1/users/123

All children inherit configuration of their parents, but are allowed to override it.

RestClient supports query parameters:

    RestClient limitedUsers = users.setParam('limit', '1000');  //  /api/v1/users?limit=1000            

Typically you would create a child of the root rest client in your component like this:

    class UserManagement {
        RestClient users;
        UserManagement(RestClient root) {
            users = root.child("/users"); // endpoint /api/v1/users
        }
    }

Every instance of RestClient has bool working property, which indicates whether this client is currently processing a request/response or not. You can use it to indicate "working" state to the user:

<p *ngIf="users.working">Sending user data to server ...</p>

This property is recursively propagated to client's parents so you can indicate this "working" state on any level. Locally (for a form), or globally (for the whole app).

// update user     
users.put(...);

Until the request is processed, john.working == true, users.working == true and root.working == true.

// read users
users.get( ... )

In this case john.working == false but users.working == true and root.working == true.

You can easily use this behaviour to disable a form and all it's buttons after submitting edited user data, but in the same time you can have universal global indicator of any HTTP communication (in your app status bar, for example).

HTTP methods

RestClient has following methods:

    Future<RestResult> get({dynamic data, Map<String, String> headers}) ...
    Future<RestResult> post(dynamic data, {Map<String, String> headers}) ...
    Future<RestResult> put(dynamic data, {Map<String, String> headers}) ...
    Future<RestResult> delete({dynamic data, Map<String, String> headers}) ...
    Future<RestResult> head({Map<String, String> headers}) ...

Use optional parameter headers to specify custom ad-hoc headers you need in this call only. Headers will be merged with your RestClient default headers, it's parent's headers etc. up to the root RestClient.

Don't use this parameter to specify Content-Type or Accept headers, see below.

RestResult

Each call returns Future<RestResult>. RestResult contains status (HTTP status, int) and data which are already converted to your desired type (see below) - Dart Map or Dart List by default.

Request/response serialization

By default, the root client is configured to produce and consume JSON and Dart Maps and Lists.

You can easily customize this behaviour to accept or produce any binary data:

    RestClient img = root.child("/images");        //  /api/v1/images     
    img.acceptsBinary("image/png");
    img.producesBinary("image/png");

Such data will be sent and received as List<int>.

You can also inject any custom serialization or deserialization you need:

    /*
    typedef Serializer = dynamic Function(dynamic payload, Map<String, String> requestHeaders);
    typedef Deserializer = dynamic Function(Response response);
    */

    client.accepts("text/csv", myCsvDeserializer);
    client.produces("text/csv", myCsvSerializer);

This configuration is inherited by client's children.

Work in progress

Suggestions, pull requests and bugreports are more than welcome.