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Flutter + AngularDart Github Search Tutorial

원문: Bloc / Tutorial / Flutter + Angular / Github Search

한국어로 번역은 현재 진행중입니다.

advanced

In the following tutorial, we’re going to build a Github Search app in Flutter and AngularDart to demonstrate how we can share the data and business logic layers between the two projects.

demo

demo

Common Github Search Library

The Common Github Search library will contain models, the data provider, the repository, as well as the bloc that will be shared between AngularDart and Flutter.

Setup

We’ll start off by creating a new directory for our application.

mkdir github_search && cd github_search

Next, we’ll create the scaffold for the common_github_search library.

mkdir common_github_search

We need to create a pubspec.yaml with the required dependencies.

name: common_github_search
description: Shared Code between AngularDart and Flutter
version: 1.0.0+1

environment:
  sdk: ">=2.0.0-dev.68.0 <3.0.0"

dependencies:
  meta: ^1.1.7
  bloc: ^0.12.0
  equatable: ^0.2.0
  http: ^0.12.0

Lastly, we need to install our dependencies.

pub get

That’s it for the project setup! Now we can get to work on building out the common_github_search package.

Github Client

The GithubClient which will be providing raw data from the Github API.

Note: You can see a sample of what the data we get back will look like here.

Let’s create github_client.dart.

import 'dart:async';
import 'dart:convert';

import 'package:http/http.dart' as http;
import 'package:common_github_search/common_github_search.dart';

class GithubClient {
  final String baseUrl;
  final http.Client httpClient;

  GithubClient({
    http.Client httpClient,
    this.baseUrl = "https://api.github.com/search/repositories?q=",
  }) : this.httpClient = httpClient ?? http.Client();

  Future<SearchResult> search(String term) async {
    final response = await httpClient.get(Uri.parse("$baseUrl$term"));
    final results = json.decode(response.body);

    if (response.statusCode == 200) {
      return SearchResult.fromJson(results);
    } else {
      throw SearchResultError.fromJson(results);
    }
  }
}

Note: Our GithubClient is simply making a network request to Github’s Repository Search API and converting the result into either a SearchResult or SearchResultError as a Future.

Next we need to define our SearchResult and SearchResultError models.

Search Result Model

Create search_result.dart.

import 'package:common_github_search/common_github_search.dart';

class SearchResult {
  final List<SearchResultItem> items;

  const SearchResult({this.items});

  static SearchResult fromJson(Map<String, dynamic> json) {
    final items = (json['items'] as List<dynamic>)
        .map((dynamic item) =>
            SearchResultItem.fromJson(item as Map<String, dynamic>))
        .toList();
    return SearchResult(items: items);
  }
}

Note: The SearchResult implementation depends on SearchResultItem.fromJson which we have not yet implemented.

Note: We aren’t including properties that aren’t going to be used in our model.

Search Result Item Model

Next, we’ll create search_result_item.dart.

import 'package:common_github_search/common_github_search.dart';

class SearchResultItem {
  final String fullName;
  final String htmlUrl;
  final GithubUser owner;

  const SearchResultItem({this.fullName, this.htmlUrl, this.owner});

  static SearchResultItem fromJson(dynamic json) {
    return SearchResultItem(
      fullName: json['full_name'] as String,
      htmlUrl: json['html_url'] as String,
      owner: GithubUser.fromJson(json['owner']),
    );
  }
}

Note: Again, the SearchResultItem implementation dependes on GithubUser.fromJson which we have not yet implemented.

Github User Model

Next, we’ll create github_user.dart.

class GithubUser {
  final String login;
  final String avatarUrl;

  const GithubUser({this.login, this.avatarUrl});

  static GithubUser fromJson(dynamic json) {
    return GithubUser(
      login: json['login'] as String,
      avatarUrl: json['avatar_url'] as String,
    );
  }
}

At this point we have finished implementing SearchResult and its dependencies so next we’ll move onto SearchResultError.

Search Result Error Model

Create search_result_error.dart.

class SearchResultError {
  final String message;

  const SearchResultError({this.message});

  static SearchResultError fromJson(dynamic json) {
    return SearchResultError(
      message: json['message'] as String,
    );
  }
}

Our GithubClient is finished so next we’ll move onto the GithubCache which will be responsible for memoizing as a performance optimization.

Github Cache

Our GithubCache will be responsible for remembering all past queries so that we can avoid making unnecessary network requests to the Github API. This will also help improve our application’s performance.

Create github_cache.dart.

import 'package:common_github_search/common_github_search.dart';

class GithubCache {
  final _cache = <String, SearchResult>{};

  SearchResult get(String term) => _cache[term];

  void set(String term, SearchResult result) => _cache[term] = result;

  bool contains(String term) => _cache.containsKey(term);

  void remove(String term) => _cache.remove(term);
}

Now we’re ready to create our GithubRepository!

Github Repository

The Github Repository is responsible for creating an abstraction between the data layer (GithubClient) and the Business Logic Layer (Bloc). This is also where we’re going to put our GithubCache to use.

Create github_repository.dart.

import 'dart:async';

import 'package:common_github_search/common_github_search.dart';

class GithubRepository {
  final GithubCache cache;
  final GithubClient client;

  GithubRepository(this.cache, this.client);

  Future<SearchResult> search(String term) async {
    if (cache.contains(term)) {
      return cache.get(term);
    } else {
      final result = await client.search(term);
      cache.set(term, result);
      return result;
    }
  }
}

Note: The GithubRepository has a dependency on the GithubCache and the GithubClient and abstracts the underlying implementation. Our application never has to know about how the data is being retrieved or where it’s coming from since it shouldn’t care. We can change how the repository works at any time and as long as we don’t change the interface we shouldn’t need to change any client code.

At this point, we’ve completed the data provider layer and the repository layer so we’re ready to move on to the business logic layer.

Github Search Event

Our Bloc will be notified when a user has typed the name of a repository which we will represent as a TextChanged GithubSearchEvent.

Create github_search_event.dart.

import 'package:equatable/equatable.dart';

abstract class GithubSearchEvent extends Equatable {
  GithubSearchEvent([List props = const []]) : super(props);
}

class TextChanged extends GithubSearchEvent {
  final String text;

  TextChanged({this.text}) : super([text]);

  @override
  String toString() => 'TextChanged { text: $text }';
}

Note: We extend Equatable so that we can compare instances of GithubSearchEvent; by default, the equality operator returns true if and only if this and other are the same instance.

Github Search State

Our presentation layer will need to have several pieces of information in order to properly lay itself out:

We can now create github_search_state.dart and implement it like so.

import 'package:equatable/equatable.dart';

import 'package:common_github_search/common_github_search.dart';

abstract class GithubSearchState extends Equatable {
  GithubSearchState([List props = const []]) : super(props);
}

class SearchStateEmpty extends GithubSearchState {
  @override
  String toString() => 'SearchStateEmpty';
}

class SearchStateLoading extends GithubSearchState {
  @override
  String toString() => 'SearchStateLoading';
}

class SearchStateSuccess extends GithubSearchState {
  final List<SearchResultItem> items;

  SearchStateSuccess(this.items) : super([items]);

  @override
  String toString() => 'SearchStateSuccess { items: ${items.length} }';
}

class SearchStateError extends GithubSearchState {
  final String error;

  SearchStateError(this.error) : super([error]);

  @override
  String toString() => 'SearchStateError';
}

Note: We extend Equatable so that we can compare instances of GithubSearchState; by default, the equality operator returns true if and only if this and other are the same instance.

Now that we have our Events and States implemented, we can create our GithubSearchBloc.

Github Search Bloc

Create github_search_bloc.dart

import 'dart:async';

import 'package:meta/meta.dart';
import 'package:rxdart/rxdart.dart';
import 'package:bloc/bloc.dart';

import 'package:common_github_search/common_github_search.dart';

class GithubSearchBloc extends Bloc<GithubSearchEvent, GithubSearchState> {
  final GithubRepository githubRepository;

  GithubSearchBloc({@required this.githubRepository});

  @override
  Stream<GithubSearchState> transform(
    Stream<GithubSearchEvent> events,
    Stream<GithubSearchState> Function(GithubSearchEvent event) next,
  ) {
    return super.transform(
      (events as Observable<GithubSearchEvent>).debounceTime(
        Duration(milliseconds: 500),
      ),
      next,
    );
  }

  @override
  void onTransition(
      Transition<GithubSearchEvent, GithubSearchState> transition) {
    print(transition);
  }

  @override
  GithubSearchState get initialState => SearchStateEmpty();

  @override
  Stream<GithubSearchState> mapEventToState(
    GithubSearchEvent event,
  ) async* {
    if (event is TextChanged) {
      final String searchTerm = event.text;
      if (searchTerm.isEmpty) {
        yield SearchStateEmpty();
      } else {
        yield SearchStateLoading();
        try {
          final results = await githubRepository.search(searchTerm);
          yield SearchStateSuccess(results.items);
        } catch (error) {
          yield error is SearchResultError
              ? SearchStateError(error.message)
              : SearchStateError('something went wrong');
        }
      }
    }
  }
}

Note: Our GithubSearchBloc converts GithubSearchEvent to GithubSearchState and has a dependency on the GithubRepository.

Note: We override the transform method to debounce the GithubSearchEvents.

Note: We override onTransition so that we can log any time a state change occurs.

Awesome! We’re all done with our common_github_search package. The finished product should look like this.

Next, we’ll work on the Flutter implementation.

Flutter Github Search will be a Flutter application which reuses the models, data providers, repositories, and blocs from common_github_search to implement Github Search.

Setup

We need to start by creating a new Flutter project in our github_search directory at the same level as common_github_search.

flutter create flutter_github_search

Next, we need to update our pubspec.yaml to include all the necessary dependencies.

name: flutter_github_search
description: A new Flutter project.

version: 1.0.0+1

environment:
  sdk: ">=2.0.0-dev.68.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  flutter_bloc: ^0.12.0
  url_launcher: ^4.0.3
  common_github_search:
    path: ../common_github_search

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:
  uses-material-design: true

Note: We are including our newly created common_github_search library as a dependency.

Now we need to install the dependencies.

flutter packages get

That’s it for project setup and since the common_github_search package contains our data layer as well as our business logic layer all we need to build is the presentation layer.

Search Form

We’re going to need to create a form with a SearchBar and SearchBody widget.

Let’s create search_form.dart.

Our SearchForm will be a StatefulWidget because it will need to create and dispose of a GithubSearchBloc.

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:url_launcher/url_launcher.dart';

import 'package:common_github_search/common_github_search.dart';

class SearchForm extends StatefulWidget {
  final GithubRepository githubRepository;

  const SearchForm({
    Key key,
    @required this.githubRepository,
  }) : super(key: key);

  @override
  _SearchFormState createState() => _SearchFormState();
}

class _SearchFormState extends State<SearchForm> {
  GithubSearchBloc _githubSearchBloc;

  @override
  void initState() {
    super.initState();
    _githubSearchBloc = GithubSearchBloc(
      githubRepository: widget.githubRepository,
    );
  }

  @override
  void dispose() {
    _githubSearchBloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        _SearchBar(githubSearchBloc: _githubSearchBloc),
        _SearchBody(githubSearchBloc: _githubSearchBloc)
      ],
    );
  }
}

Note: The GithubRepository is injected into the SearchForm.

Note: The GithubSearchBloc is created and disposed by the SearchForm.

Next, we’ll implement _SearchBar.

SearchBar is also going to be a StatefulWidget because it will need to maintain its own TextController so that we can keep track of what a user has entered as input.

class _SearchBar extends StatefulWidget {
  final GithubSearchBloc githubSearchBloc;

  _SearchBar({Key key, this.githubSearchBloc}) : super(key: key);

  @override
  State<_SearchBar> createState() => _SearchBarState();
}

class _SearchBarState extends State<_SearchBar> {
  final _textController = TextEditingController();

  GithubSearchBloc get githubSearchBloc => widget.githubSearchBloc;

  @override
  Widget build(BuildContext context) {
    return TextField(
      controller: _textController,
      autocorrect: false,
      onChanged: (text) {
        githubSearchBloc.dispatch(
          TextChanged(text: text),
        );
      },
      decoration: InputDecoration(
        prefixIcon: Icon(Icons.search),
        suffixIcon: GestureDetector(
          child: Icon(Icons.clear),
          onTap: _onClearTapped,
        ),
        border: InputBorder.none,
        hintText: 'Enter a search term',
      ),
    );
  }

  void _onClearTapped() {
    _textController.text = '';
    githubSearchBloc.dispatch(TextChanged(text: ''));
  }
}

Note: _SearchBar has a dependency on GitHubSearchBloc because it is responsible for notifying the bloc of TextChanged events.

We’re done with _SearchBar, now onto _SearchBody.

Search Body

SearchBody is a StatelessWidget which will be responsible for displaying search results, errors, and loading indicators. It will be the consumer of the GithubSearchBloc.

class _SearchBody extends StatelessWidget {
  final GithubSearchBloc githubSearchBloc;

  const _SearchBody({Key key, this.githubSearchBloc}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<GithubSearchEvent, GithubSearchState>(
      bloc: githubSearchBloc,
      builder: (BuildContext context, GithubSearchState state) {
        if (state is SearchStateEmpty) {
          return Text('Please enter a term to begin');
        }
        if (state is SearchStateLoading) {
          return CircularProgressIndicator();
        }
        if (state is SearchStateError) {
          return Text(state.error);
        }
        if (state is SearchStateSuccess) {
          return state.items.isEmpty
              ? Text('No Results')
              : Expanded(child: _SearchResults(items: state.items));
        }
      },
    );
  }
}

Note: _SearchBody has a dependency on GithubSearchBloc and uses BlocBuilder in order to rebuild in response to state changes.

If our state is SearchStateSuccess we render _SearchResults which we will implement next.

Search Results

SearchResults is a StatelessWidget which takes a List<SearchResultItem> and displays them as a list of SearchResultItems.

class _SearchResults extends StatelessWidget {
  final List<SearchResultItem> items;

  const _SearchResults({Key key, this.items}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: items.length,
      itemBuilder: (BuildContext context, int index) {
        return _SearchResultItem(item: items[index]);
      },
    );
  }
}

Note: We use ListView.builder in order to construct a scrollable list of SearchResultItem.

It’s time to implement _SearchResultItem.

Search Result Item

SearchResultItem is a StatelessWidget and is responsible for rendering the information for a single search result. It is also responsible for handling user interaction and navigating to the repository url on a user tap.

class _SearchResultItem extends StatelessWidget {
  final SearchResultItem item;

  const _SearchResultItem({Key key, @required this.item}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ListTile(
      leading: CircleAvatar(
        child: Image.network(item.owner.avatarUrl),
      ),
      title: Text(item.fullName),
      onTap: () async {
        if (await canLaunch(item.htmlUrl)) {
          await launch(item.htmlUrl);
        }
      },
    );
  }
}

Note: We use the url_launcher package to open external urls.

Putting it all together

At this point our search_form.dart should look like

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:url_launcher/url_launcher.dart';

import 'package:common_github_search/common_github_search.dart';

class SearchForm extends StatefulWidget {
  final GithubRepository githubRepository;

  const SearchForm({
    Key key,
    @required this.githubRepository,
  }) : super(key: key);

  @override
  _SearchFormState createState() => _SearchFormState();
}

class _SearchFormState extends State<SearchForm> {
  GithubSearchBloc _githubSearchBloc;

  @override
  void initState() {
    super.initState();
    _githubSearchBloc = GithubSearchBloc(
      githubRepository: widget.githubRepository,
    );
  }

  @override
  void dispose() {
    _githubSearchBloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        _SearchBar(githubSearchBloc: _githubSearchBloc),
        _SearchBody(githubSearchBloc: _githubSearchBloc)
      ],
    );
  }
}

class _SearchBar extends StatefulWidget {
  final GithubSearchBloc githubSearchBloc;

  _SearchBar({Key key, this.githubSearchBloc}) : super(key: key);

  @override
  State<_SearchBar> createState() => _SearchBarState();
}

class _SearchBarState extends State<_SearchBar> {
  final _textController = TextEditingController();

  GithubSearchBloc get githubSearchBloc => widget.githubSearchBloc;

  @override
  Widget build(BuildContext context) {
    return TextField(
      controller: _textController,
      autocorrect: false,
      onChanged: (text) {
        githubSearchBloc.dispatch(
          TextChanged(text: text),
        );
      },
      decoration: InputDecoration(
        prefixIcon: Icon(Icons.search),
        suffixIcon: GestureDetector(
          child: Icon(Icons.clear),
          onTap: _onClearTapped,
        ),
        border: InputBorder.none,
        hintText: 'Enter a search term',
      ),
    );
  }

  void _onClearTapped() {
    _textController.text = '';
    githubSearchBloc.dispatch(TextChanged(text: ''));
  }
}

class _SearchBody extends StatelessWidget {
  final GithubSearchBloc githubSearchBloc;

  const _SearchBody({Key key, this.githubSearchBloc}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<GithubSearchEvent, GithubSearchState>(
      bloc: githubSearchBloc,
      builder: (BuildContext context, GithubSearchState state) {
        if (state is SearchStateEmpty) {
          return Text('Please enter a term to begin');
        }
        if (state is SearchStateLoading) {
          return CircularProgressIndicator();
        }
        if (state is SearchStateError) {
          return Text(state.error);
        }
        if (state is SearchStateSuccess) {
          return state.items.isEmpty
              ? Text('No Results')
              : Expanded(child: _SearchResults(items: state.items));
        }
      },
    );
  }
}

class _SearchResults extends StatelessWidget {
  final List<SearchResultItem> items;

  const _SearchResults({Key key, this.items}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: items.length,
      itemBuilder: (BuildContext context, int index) {
        return _SearchResultItem(item: items[index]);
      },
    );
  }
}

class _SearchResultItem extends StatelessWidget {
  final SearchResultItem item;

  const _SearchResultItem({Key key, @required this.item}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ListTile(
      leading: CircleAvatar(
        child: Image.network(item.owner.avatarUrl),
      ),
      title: Text(item.fullName),
      onTap: () async {
        if (await canLaunch(item.htmlUrl)) {
          await launch(item.htmlUrl);
        }
      },
    );
  }
}

Now all that’s left to do is implement our main app in main.dart.

import 'package:flutter/material.dart';

import 'package:meta/meta.dart';
import 'package:common_github_search/common_github_search.dart';
import 'package:flutter_github_search/search_form.dart';

void main() {
  final GithubRepository _githubRepository = GithubRepository(
    GithubCache(),
    GithubClient(),
  );

  runApp(App(githubRepository: _githubRepository));
}

class App extends StatelessWidget {
  final GithubRepository githubRepository;

  const App({
    Key key,
    @required this.githubRepository,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Github Search',
      home: Scaffold(
        appBar: AppBar(title: Text('Github Search')),
        body: SearchForm(
          githubRepository: githubRepository,
        ),
      ),
    );
  }
}

Note: Our GithubRepository is created in main and injected into our App.

That’s all there is to it! We’ve now successfully implemented a github search app in Flutter using the bloc and flutter_bloc packages and we’ve successfully separated our presentation layer from our business logic.

The full source can be found here.

Finally, we’re going to build our AngularDart Github Search app.

AngularDart Github Search will be an AngularDart application which reuses the models, data providers, repositories, and blocs from common_github_search to implement Github Search.

Setup

We need to start by creating a new AngularDart project in our github_search directory at the same level as common_github_search.

stagehand web-angular

Activate stagehand by running pub global activate stagehand

We can then go ahead and replace the contents of pubspec.yaml with:

name: angular_github_search
description: A web app that uses AngularDart Components

environment:
  sdk: ">=2.0.0 <3.0.0"

dependencies:
  angular: ^5.0.0
  angular_components: ^0.9.0
  angular_bloc: ^0.8.0
  common_github_search:
    path: ../common_github_search

dev_dependencies:
  angular_test: ^2.0.0
  build_runner: ^0.10.0
  build_test: ^0.10.2
  build_web_compilers: ^0.4.0
  test: ^1.0.0

Search Form

Just like in our Flutter app, we’re going to need to create a SearchForm with a SearchBar and SearchBody component.

Our SearchForm component will implement OnInit and OnDestroy because it will need to create and dispose of a GithubSearchBloc.

Let’s create github_search_form_component.dart.

import 'package:angular/angular.dart';
import 'package:angular_bloc/angular_bloc.dart';

import 'package:common_github_search/common_github_search.dart';
import 'package:angular_github_search/src/github_search.dart';

@Component(
    selector: 'github-search-form',
    templateUrl: 'github_search_form_component.html',
    directives: [
      SearchBarComponent,
      SearchBodyComponent,
    ],
    pipes: [
      BlocPipe
    ])
class SearchFormComponent implements OnInit, OnDestroy {
  @Input()
  GithubRepository githubRepository;

  GithubSearchBloc githubSearchBloc;

  @override
  void ngOnInit() {
    githubSearchBloc = GithubSearchBloc(
      githubRepository: githubRepository,
    );
  }

  @override
  void ngOnDestroy() {
    githubSearchBloc.dispose();
  }
}

Note: The GithubRepository is injected into the SearchFormComponent.

Note: The GithubSearchBloc is created and disposed by the SearchFormComponent.

Our template (github_search_form_component.html) will look like:

<div>
  <h1>Github Search</h1>
  <github-search-bar [githubSearchBloc]="githubSearchBloc"></github-search-bar>
  <github-search-body [state]="githubSearchBloc | bloc"></github-search-body>
</div>

Next, we’ll implement the SearchBar Component.

Search Bar

SearchBar is a component which will be responsible for taking in user input and notifying the GithubSearchBloc of text changes.

Create github_search_bar_component.dart.

import 'package:angular/angular.dart';

import 'package:common_github_search/common_github_search.dart';

@Component(
  selector: 'github-search-bar',
  templateUrl: 'github_search_bar_component.html',
)
class SearchBarComponent {
  @Input()
  GithubSearchBloc githubSearchBloc;

  void onTextChanged(String text) {
    githubSearchBloc.dispatch(TextChanged(text: text));
  }
}

Note: SearchBarComponent has a dependency on GitHubSearchBloc because it is responsible for notifying the bloc of TextChanged events.

Next, we can create github_search_bar_component.html.

<label for="term" class="clip">Enter a search term</label>
<input
  id="term"
  placeholder="Enter a search term"
  class="input-reset outline-transparent glow o-50 bg-near-black near-white w-100 pv2 border-box b--white-50 br-0 bl-0 bt-0 bb-ridge mb3"
  autofocus
  (keyup)="onTextChanged($event.target.value)"
/>

We’re done with SearchBar, now onto SearchBody.

Search Body

SearchBody is a component which will be responsible for displaying search results, errors, and loading indicators. It will be the consumer of the GithubSearchBloc.

Create github_search_body_component.dart

import 'package:angular/angular.dart';
import 'package:angular_components/angular_components.dart';

import 'package:common_github_search/common_github_search.dart';
import 'package:angular_github_search/src/github_search.dart';

@Component(
  selector: 'github-search-body',
  templateUrl: 'github_search_body_component.html',
  directives: [
    coreDirectives,
    MaterialSpinnerComponent,
    MaterialIconComponent,
    SearchResultsComponent,
  ],
)
class SearchBodyComponent {
  @Input()
  GithubSearchState state;

  bool get isEmpty => state is SearchStateEmpty;
  bool get isLoading => state is SearchStateLoading;
  bool get isSuccess => state is SearchStateSuccess;
  bool get isError => state is SearchStateError;

  List<SearchResultItem> get items =>
      isSuccess ? (state as SearchStateSuccess).items : [];

  String get error => isError ? (state as SearchStateError).error : '';
}

Note: SearchBodyComponent has a dependency on GithubSearchState which is provided by the GithubSearchBloc using the angular_bloc bloc pipe.

Create github_search_body_component.html

<div *ngIf="state != null" class="mw10">
  <div *ngIf="isEmpty" class="tc">
    <material-icon icon="info" class="light-blue"></material-icon>
    <p>Please enter a term to begin</p>
  </div>
  <div *ngIf="isLoading" class="tc"><material-spinner></material-spinner></div>
  <div *ngIf="isError" class="tc">
    <material-icon icon="error" class="light-red"></material-icon>
    <p></p>
  </div>
  <div *ngIf="isSuccess">
    <div *ngIf="items.length == 0" class="tc">
      <material-icon icon="warning" class="light-yellow"></material-icon>
      <p>No Results</p>
    </div>
    <github-search-results [items]="items"></github-search-results>
  </div>
</div>

If our state isSuccess we render SearchResults which we will implement next.

Search Results

SearchResults is a component which takes a List<SearchResultItem> and displays them as a list of SearchResultItems.

Create github_search_results_component.dart

import 'package:angular/angular.dart';

import 'package:common_github_search/common_github_search.dart';
import 'package:angular_github_search/src/github_search.dart';

@Component(
  selector: 'github-search-results',
  templateUrl: 'github_search_results_component.html',
  directives: [coreDirectives, SearchResultItemComponent],
)
class SearchResultsComponent {
  @Input()
  List<SearchResultItem> items;
}

Next up we’ll create github_search_results_component.html.

<ul class="list pa0 ma0">
  <li *ngFor="let item of items" class="pa2 cf">
    <github-search-result-item [item]="item"></github-search-result-item>
  </li>
</ul>

Note: We use ngFor in order to construct a list of SearchResultItem components.

It’s time to implement SearchResultItem.

Search Result Item

SearchResultItem is a component that is responsible for rendering the information for a single search result. It is also responsible for handling user interaction and navigating to the repository url on a user tap.

Create github_search_result_item_component.dart.

import 'package:angular/angular.dart';

import 'package:common_github_search/common_github_search.dart';

@Component(
  selector: 'github-search-result-item',
  templateUrl: 'github_search_result_item_component.html',
)
class SearchResultItemComponent {
  @Input()
  SearchResultItem item;
}

and the corresponding template in github_search_result_item_component.html.

<div class="fl w-10 h-auto">
  <img class="br-100" src="" />
</div>
<div class="fl w-90 ph3">
  <h1 class="f5 ma0"></h1>
  <p>
    <a href="" class="light-blue" target="_blank"
      ></a
    >
  </p>
</div>

Putting it all together

We have all of our components and now it’s time to put them all together in our app_component.dart.

import 'package:angular/angular.dart';

import 'package:common_github_search/common_github_search.dart';
import 'package:angular_github_search/src/github_search.dart';

@Component(
  selector: 'my-app',
  template:
      '<github-search-form [githubRepository]="githubRepository"></github-search-form>',
  directives: [SearchFormComponent],
)
class AppComponent {
  final githubRepository = GithubRepository(
    GithubCache(),
    GithubClient(),
  );
}

Note: We’re creating the GithubRepository in the AppComponent and injecting it into the SearchForm component.

That’s all there is to it! We’ve now successfully implemented a github search app in AngularDart using the bloc and angular_bloc packages and we’ve successfully separated our presentation layer from our business logic.

The full source can be found here.

Summary

In this tutorial we created a Flutter and AngularDart app while sharing all of the models, data providers, and blocs between the two.

The only thing we actually had to write twice was the presentation layer (UI) which is awesome in terms of efficiency and development speed. In addition, it’s fairly common for web apps and mobile apps to have different user experiences and styles and this approach really demonstrates how easy it is to build two apps that look totally different but share the same data and business logic layers.

The full source can be found here.

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