In this tutorial, we will set up a GraphQL endpoint in a Strapi backend along with Flutter, a powerful open-source UI development kit for Android, iOS, Linux, Mac, Windows, Google Fuchsia, and the web to build a Todo app.

What is Strapi?

Strapi is an open-source headless CMS based on Nodejs that lets developers design APIs fast and manage content efficiently. Some features it offers among others include:

Open-source

Strapi is 100% open-source. It is hosted on GitHub with over 50K stars and a large community for support. Strapi also has a forum and Discord server where Strapi users can ask questions and get answers and discuss the newest features and releases of Strapi.

Customizable

Strapi is highly customizable with feature-rich plugins. Recently they introduced workflows which enable you to easily create, visualize and manage review content stages hence improving the collaboration experience and giving you control over the entire content lifecycle. A complete list of features and enhancements is available in the Strapi changelog. Strapi also has a highly customizable Amin UI for building collections and APIs with a marketplace where developers can search, install and interact with plugins.

Self-hosted

You need no server. Strapi comes bundled with its server. All we have to do is scaffold a Strapi project, run its server, and we are good to go. You don't need to write any server code. Strapi does all that.

RESTful or GraphQL

Strapi hosts your Collection in RESTful and GraphQL endpoints, and these endpoints can be consumed by clients (Angular, Flutter, Desktop, cURL, etc.). With Strapi, you don't have to worry about server setup and coding. There will be no need to create models and controllers because Strapi has all that baked in and ready to use. From the Strapi admin UI, we can create our collections and single types. A collection maps to the endpoints:

• POST /YOUR_COLLECTION_s: Creates new content.
• GET /YOUR_COLLECTION_s: Gets all the contents.
• GET /YOUR_COLLECTION_s/:ID: Gets a single content based on its ID.
• PUT /YOUR_COLLECTION_s/:ID: Edits a content
• DELETE /YOUR_COLLECTION_s/:ID: Deletes a content.

We will be building a todo app in Flutter to demonstrate how we can communicate from a Flutter app to a Strapi backend to store, edit and delete our todo items.

Requirements

To follow this tutorial, you need to have some binaries installed on your machine:

• Nodejs and NPM: You must have Node.js binaries installed on our machine. You can download it from here Node.js download page. Node v18.x is recommended for Strapi v4.3.9 and above
• Yarn: Very fast Node package manager. You can install via NPM: npm i yarn -g.
• flutter CLI: This command-line tool is used to manage a Flutter project. We can use it to create a Flutter project. Visit https://flutter.dev/docs/get-started/install to install the CLI for your machine.

Scaffold a Strapi

We will create the main folder where our Strapi project and Flutter project will reside.

  mkdir todo-app

Move into the folder: cd todo-app then create a Strapi project with the command below:

  yarn create strapi-app todo-app-backend --quickstart
  # OR
  npx create-strapi-app todo-app-backend --quickstart

This command creates a Strapi project in todo-app with necessary dependencies and starts the server by running yarn develop. The page http://localhost:1337/admin/auth/register/ will be opened in the browser for you to set up your Strapi administrator credentials.

Fill in your details and click on the "LET'S START" button. Strapi will create your account and will load the admin UI like below. From this page, we create our collections.

Build the todo collection

We are building a todo app so we will create a Todo model that looks exactly like the one below:

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  Todo {
    name
    done
  }

The model above represents a todo item we will have in our app. The name is the name or text of a todo, e.g., "Read 100 years of love." The done is a boolean field that indicates whether a todo item has been done or not.

Now, let's create the collection.

On the admin UI, click on Content-Type Builder, then, click on the + Create new collection type button. A modal will pop up; on the popup modal, type "todo" in the Display name input box. The "todo" will be the name of our collection type.

Click on the "Continue" button and on the following UI that appears on the exact modal, create the fields for the "todo" collection.

Select the "Text" field on the next display and type in "name."

Click on the "+ Add another field" button, and on the next display, select "Boolean" and type in "done" on the next display that appears.

Click on the "Finish" button, the modal will disappear, and we will see the "todo" collection on the page with the fields we just added.

Click on the "Save" button on the top right. It will save our "todo" collection. We will see that a "Todo" is a content type on the sidebar menu of the dashboard.

Seed mock data

We will add mock Todo data to our collection.

But before that, we will disable the Draft/Publish feature so that we can directly save and publish items easily(note that this is not recommended in a production environment.)

From the dashboard, we click on Content-type Builder -> Todo and click on the edit icon

From the popup menu that appears we select the advanced advanced settings tab and uncheck the Draft&Publish checkbox and click on Finish

Now click on Content Manager on the left sidebar; under the todo collection type, click on the + Create new entry button at the top-right of the page. A Create an entry UI will appear.

You will see input boxes for all the fields in our Todo model. Add the data below:

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- `name` -> Read 100 years of love
- `done` -> false

After adding them, save and go back to the todo page to add another entry

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- `name` -> Find a new home
- `done` -> false

Feel free to add many items as you like.

Next, we will open access for all users, both unauthenticated and authenticated users.

Open access

Click on the Settings item on the sidebar menu.

Go to the "USERS & PERMISSIONS PLUGIN" section and click on "Roles," and then on Public on the right section.

A Public page is loaded in this section. Scroll down to the Todo area under the Permission section and check the Select all box, and finally click on the Save button on the top-right page, to make our endpoints accessible to the Public.

In the next step, we add GraphQL to our collection.

Strapi GraphQL plugin

By default, Strapi provides our endpoints via REST, but here we want the endpoints to be accessed via GraphQL. To do that, we use the following command to install the GraphQL plugin for Strapi.

  yarn strapi install graphql

Article updated by: Kevine Nzapdi

Strapi will install the dependency and rebuild the admin UI. Visiting http://localhost:1337/graphql in your browser, will load the GraphQL playground:

We can play with our GraphQL from the playground. On the playground, Strapi will create GraphQL mutations and queries for the todos collection that looks like the one below.

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    input TodoInput {
      name: String
      done: Boolean
    }

    // Todo's type definition
    type Todo {
      name: String
      done: Boolean
      createdAt: DateTime
      updatedAt: DateTime
    }

    type TodoEntity {
      id: ID
      attributes: Todo
    }

    type Query {
      todo(id: ID): TodoEntityResponse
      todos(
        filters: TodoFiltersInput
        pagination: PaginationArg = {}
        sort: [String] = []
      ): TodoEntityResponseCollection
    }

Note: To find all the queries and mutations created for your collections, click on the “SCHEMA” item on the middle right-side of the GraphQL Playground. A right-side bar will appear listing the queries and mutations schema for your collections.

All the queries and mutations will be done via http://localhost:1337/graphql. Now let's test some queries and mutations in the GraphQL playground.

Get all todos

To retrieve all the todos in our collection, we run the query:

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# Write your query or mutation here
query {
  todos {
    data {
      id
      attributes {
        name
        done
      }
    }
  }
}

Get a todo

To retrieve a single todo item from our collection we run the query:

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query {
  todo(id: 1) {
    data {
      id
      attributes {
        name
        done
      }
    }
  }
}

Create a new todo

To create a new todo we run the below mutation:

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mutation createTodo {
  createTodo(data: { name: "Find a new house", done: false }) {
    data {
      id
      attributes {
        name
        done
      }
    }
  }
}

Update a todo

To update to todo item run the below mutation:

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mutation updateTodo {
  updateTodo(id: "1", data: { done: true }) {
    data {
      id
      attributes {
        name
        done
      }
    }
  }
}

Delete a todo

To delete a todo run the mutation below:

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mutation deleteTodo {
  deleteTodo(id: 22) {
    data {
      id
      attributes {
        name
        done
      }
    }
  }
}

Now it’s time to build the Flutter app.

Flutter

Make sure you have the Flutter and Dart SDK fully installed on your machine. If you are having issues with Flutter, run flutter doctor to iron them out. Once everything is set up, run flutter --version to make sure the Flutter CLI is available globally in your system.

Setting up Flutter

Step out of the todo-app-backend folder and run the command below:

  flutter create todo_app_frontend

The command creates a Flutter project directory called todo_frontend that contains a simple demo app that uses Material Components. So now we should have two folders(todo-app-backend and todo_app_frontend) in the todo-app folder

Move into the todo_app_frontend folder:

  cd todo_app_frontend

Make sure your simulator/emulator is running. You can check if your emulator is running and active by running the command: flutter devices.

Once everything is okay,we start the app with the command flutter run.

Build the Flutter app

We will see the app launched in our emulator. So the need step will consist of building the actual todo flutter app. We go back to the Flutter project. You will see a main.dart file in the project. That is the main file in Flutter projects, and it is where the app is being bootstrapped from. Everything in Flutter is a widget.

Our app will have three widgets:

• CreateTodo: This widget is where we will create new todos.
• TodoList: This widget will get the list of all the todos in our system.
• ViewTodo: This widget is where we will view our todos, and edit and delete them.

Our final app will look like this:

1-flutter-app.png

To build the app, we will use these dependencies:

• graphql_flutter: This is a GraphQL client for Flutter that gives us APIs to run queries and mutations conversationally.
• intl: This library provides us with DateTime formatting capabilities.

Open the pubspec.yaml file, go to the dependencies section and add graphql_flutter and intl.

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    dependencies:
      flutter:
        sdk: flutter
      graphql_flutter: ^5.1.2
      intl: ^0.18.1

Then run flutter pub get in your terminal. Flutter will install the dependencies in your project.

Create a project structure like the screenshot below:

We have two folders in the lib directory. The first one API hosts a file graphqlConfig.dart that hold the GraphQL configurations while the screens holds the different screens of our app.

We will flesh out the code in them. To connect to a GraphQL server, we will create a GraphQLClient. This GraphQLClient will contain a link and cache system.

According to comments on the GraphQLClient source code: The link is a Link over which GraphQL documents will be resolved into a Response. The cache is the GraphQLCache to use for caching results and optimistic updates.

We will create a GraphQLConfiguration class in the lib/api/graphQLConfig.dart file, and this class will have a clientToQuery method that will return an instance of GraphQLClient.

GraphQLConfig.dart

Open lib/GraphQLConfig.dart and paste the below code:

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    import "package:flutter/material.dart";
    import "package:graphql_flutter/graphql_flutter.dart";
    class GraphQLConfiguration {
      static HttpLink httpLink = HttpLink(
        'http://10.0.2.2:1337/graphql',
      );
      static ValueNotifier<GraphQLClient> client = ValueNotifier(
        GraphQLClient(
          cache: GraphQLCache(),
          link: httpLink,
        ),
      );
      static ValueNotifier<GraphQLClient> clientToQuery() {
        return client;
      }
    }


    static HttpLink httpLink = HttpLink(
      'http://10.0.2.2:1337/graphql',
    );

This particular block code above sets the link where the GraphQLClient will resolve documents. You can notice that the link is http://10.0.2.2:1337/graphql, instead of http://localhost:1337/graphql. The emulator proxies HTTP requests made inside it. Since we are running the flutter app on an emulator, the proxy URL is 10.0.2.2, and this URL will forward the HTTP request made to the URL to localhost.

Our Strapi backend runs on localhost:1337, we have to make an HTTP request to 10.0.2.2:1337. The emulator will proxy it to localhost:1337.

The cache: GraphQLCache() makes the GraphQLClient use its internal cache. We create an instance of GraphQLClient and store it in the client. This is returned in the clientToQuery static method.

main.dart

Open the lib/main.dart and paste the following code:

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    import 'dart:math';
    import 'package:flutter/material.dart';
    import 'package:graphql_flutter/graphql_flutter.dart';
    import 'package:intl/intl.dart';
    import 'package:todo_frontend/screens/createTodo.dart';
    import 'package:todo_frontend/screens/viewTodo.dart';
    import 'package:todo_frontend/api/graphqlConfig.dart';

    void main() {
      runApp(const MyApp());
    }
    class MyApp extends StatelessWidget {
      const MyApp({super.key});
      // This widget is the root of your application.
      @override
      Widget build(BuildContext context) {
        return GraphQLProvider(
            client: GraphQLConfiguration.clientToQuery(),
            child: MaterialApp(
              title: 'Todo App',
              theme: ThemeData(
                colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
                useMaterial3: true,
              ),
              home: const TodoList(),
            ));
      }
    }

Note that we imported all the packages that we will be using.

The main function is the entry point where the execution starts. The runApp function starts rendering the widgets in our app. Notice that we passed it MyApp widget. This widget is the first widget to render its UI in our todo app.

Each widget overrides the build method from either StatelessWidget or StatefulWidget to return widgets that will render the UI of our app.

A StatelessWidget manages no local state. It is just like a functional component in Reactjs without useState. A StatefulWidget manages a local state. It is like a functional component in Reactjs with the useState hook.

The MyApp extends the StatelesWidget because it will be managing no state. In its build method, we have a context argument that is of the BuildContext instance. BuildContext is a handle for the location of a widget in the widget tree.

The GraphQLClient has Mutation and Query widgets. These widgets give us options from where we can make queries and mutations to our GraphQL server. Before making these queries and mutations, we must wrap the Query and Mutation widgets in the GraphQLProvider widget.

That's why in the build method of the MyApp, we wrapped the MaterialApp widget in GraphQLProvider. As a result, the TodoList widget can now access the Query and Mutation widgets.

TodoList

This widget makes a query to fetch all the todos in our Strapi backend, which happens when the widgets load. Then, it will render the todos in a list. Each todo list will have an onTap event registered on them so that when pressed, a ViewTodo widget screen is opened to view the item.

Also, in this widget, we will have a FloatingActionButton , when clicked will open the CreateTodo widget screen for us to add new todos.

Paste the code below to build the TodoList screen after the MyApp widget in main.dart.

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  class TodoList extends StatefulWidget {
    const TodoList({Key? key}) : super(key: key);

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

  class TodoListState extends State<TodoList> {
    String readTodos = """
    query {
  	todos(sort:"createdAt:desc") {
      data {
        id
        attributes {
          name
          done
          createdAt
        }
      }
    }
  } """;

    var colors = [
      Colors.indigo,
      Colors.green,
      Colors.purple,
      Colors.pinkAccent,
      Colors.red,
      Colors.black
    ];

    Random random = Random();
    List<Map<String, dynamic>> todos = [];

    randomColors() {
      int randomNumber = random.nextInt(colors.length);
      return colors[randomNumber];
    }

    onChange(b) {
      return true;
    }

    @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: Query(
            options: QueryOptions(
              document: gql(readTodos),
              pollInterval: const Duration(seconds: 0),
            ),
            builder: (QueryResult result,
                {VoidCallback? refetch, FetchMore? fetchMore}) {
              if (result.hasException) {
                return Text(result.exception.toString());
              }

              if (result.isLoading) {
                return const Center(child: Text('Loading'));
              }

              Map<String, dynamic> todos = result.data?["todos"];

              return Scaffold(
                backgroundColor: Colors.white,
                body: Column(children: [
                  Container(
                      alignment: Alignment.centerLeft,
                      padding: const EdgeInsets.fromLTRB(8, 50, 0, 9),
                      color: Colors.blue,
                      child: const Text(
                        "Todo",
                        style: TextStyle(
                            fontSize: 45,
                            fontWeight: FontWeight.bold,
                            color: Colors.white),
                      )),
                  const SizedBox(
                    height: 10,
                  ),
                  Padding(
                    padding: const EdgeInsets.symmetric(vertical: 3),
                    child: ListView.builder(
                      itemCount: todos["data"].length,
                      shrinkWrap: true,
                      itemBuilder: (context, index) {
                        return GestureDetector(
                            onTap: () {
                              Navigator.push(
                                context,
                                MaterialPageRoute(
                                  builder: (context) => ViewTodo(
                                      id: todos["data"][index]["id"],
                                      refresh: () {
                                        refetch!();
                                      }),
                                ),
                              );
                            },
                            child: Container(
                              margin: const EdgeInsets.fromLTRB(10, 0, 10, 10),
                              padding: const EdgeInsets.fromLTRB(10, 0, 10, 10),
                              decoration: BoxDecoration(
                                borderRadius:
                                    const BorderRadius.all(Radius.circular(7)),
                                color: randomColors(),
                              ),
                              child: Row(
                                children: [
                                  Expanded(
                                    child: Column(
                                      crossAxisAlignment:
                                          CrossAxisAlignment.start,
                                      children: [
                                        Padding(
                                          padding: const EdgeInsets.fromLTRB(
                                              0, 6, 0, 6),
                                          // child: Text('To do'),
                                          child: Text(
                                              todos['data'][index]["attributes"]
                                                      ["name"]
                                                  .toString(),
                                              style: const TextStyle(
                                                  fontSize: 16,
                                                  color: Colors.white,
                                                  fontWeight: FontWeight.bold)),
                                        ),
                                        Text(
                                          DateFormat("yMMMEd")
                                              .format(DateTime.parse(todos['data']
                                                          [index]["attributes"]
                                                      ["createdAt"]
                                                  .toString()))
                                              .toString(),
                                          style: const TextStyle(
                                              color: Colors.white),
                                        ),
                                      ],
                                    ),
                                  ),
                                  Checkbox(
                                    value: todos["data"][index]["attributes"]
                                        ["done"],
                                    onChanged: onChange,
                                    checkColor: Colors.white,
                                    activeColor: Colors.white,
                                  )
                                ],
                              ),
                            ));
                      },
                    ),
                  ),
                ]),
                floatingActionButton: FloatingActionButton(
                  foregroundColor: Colors.white,
                  backgroundColor: Colors.green,
                  onPressed: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(
                        builder: (context) => CreateTodo(refresh: () {
                          refetch!();
                        }),
                      ),
                    );
                  },
                  tooltip: 'Add new todo',
                  child: const Icon(Icons.add),
                ),
              );
            }),
      );
    }
  }

The TodoList uses the createState method to create its mutatable state at the TodoListState, and this TodoListState renders the UI widget for the TodoList.

Widgets that extend the State class are:

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- The logic and internal state for a [StatefulWidget].
- The State is information that
- (1) can be read synchronously when the widget is built and
- (2) might change during the widget's lifetime. It is the responsibility of the widget implementer to ensure that the [State] is promptly notified when such state changes, using [State.setState].

Inside the TodoListState widget, we start by defining the query to read the todos in the readTodos String variable. We have an array of colors, and we used this to change the background color of our todos list widget randomly.

The todos variables will hold the todos list fetched from our backend. The randomColors is the method that will randomly return a background color for each todo widget.

Inside the build method, see that the Query widget wraps the whole widget tree. This is done to reference the returned todos. We also have a vital function refetch that we can use to refresh our todos list when a change occurs.

This Query widget uses the document method in its options object to query for the todos list. It does this by calling the gql method with the readTodos variable. The result of this query is returned in the builder function's result argument.

Inside the function, we retrieve the result and assign it to the todos collection:

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    Map<String, dynamic> todos = result.data?["todos"];

Then we return our UI starting from the Scaffold(...) widget. We use todos[``"``data``"``] to render each result there in the ListView.builder.

We then use GestureDetector widget to which we is set an onTap event.

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child: ListView.builder(
  itemCount: todos["data"].length,
  shrinkWrap: true,
  itemBuilder: (context, index) {
    return GestureDetector(
        onTap: () {
          Navigator.push(
            context,
            MaterialPageRoute(
              builder: (context) => ViewTodo(
                  id: todos["data"][index]["id"],
                  refresh: () {
                    refetch!();
                  }),
            ),
          );
        },
        child: Container(
          margin: const EdgeInsets.fromLTRB(10, 0, 10, 10),
          padding: const EdgeInsets.fromLTRB(10, 0, 10, 10),
          decoration: BoxDecoration(
            borderRadius:
                const BorderRadius.all(Radius.circular(7)),
            color: randomColors(),
          ),
          child: Row(
            children: [
              Expanded(
                child: Column(
                  crossAxisAlignment:
                      CrossAxisAlignment.start,
                  children: [
                    Padding(
                      padding: const EdgeInsets.fromLTRB(
                          0, 6, 0, 6),
                      // child: Text('To do'),
                      child: Text(
                          todos['data'][index]["attributes"]
                                  ["name"]
                              .toString(),
                          style: const TextStyle(
                              fontSize: 16,
                              color: Colors.white,
                              fontWeight: FontWeight.bold)),
                    ),
                    Text(
                      DateFormat("yMMMEd")
                          .format(DateTime.parse(todos['data']
                                      [index]["attributes"]
                                  ["createdAt"]
                              .toString()))
                          .toString(),
                      style: const TextStyle(
                          color: Colors.white),
                    ),
                  ],
                ),
              ),
              Checkbox(
                value: todos["data"][index]["attributes"]
                    ["done"],
                onChanged: onChange,
                checkColor: Colors.white,
                activeColor: Colors.white,
              )
            ],
          ),
        ));
  },
),

From the code you can notice that when a Todo item in the list is pressed or tapped, the ViewTodo widget screen is launched. We passed to it the id of the Todo and a refresh function. This refresh function calls the refetch function returned by the Query widget. This is done to refresh the TodoList view from the ViewTodo widget when a change to the Todo occur.

The FloatingActionButton:

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    floatingActionButton: FloatingActionButton(
      foregroundColor: Colors.white,
      backgroundColor: Colors.green,
      onPressed: () {
        Navigator.push(
          context,
          MaterialPageRoute(
            builder: (context) => CreateTodo(refresh: () {
              refetch!();
            }),
          ),
        );
      },
      tooltip: 'Add new todo',
      child: const Icon(Icons.add),
    ),

It launches the CreateTodo widget on clicked. Let's look at the ViewTodo widget.

ViewTodo

We will perform three actions on a Todo in this widget.

• Query a todo using the id passed to this widget,
• Update a Todo, and
• Delete the Todo.

To build this screen paste the code below in lib/screens/ViewTodo.dart:

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    import 'package:flutter/material.dart';
    import 'package:graphql_flutter/graphql_flutter.dart';
    import 'package:todo_frontend/api/graphqlConfig.dart';
    String readTodo = """
    query(\$id: ID!) {
      todo(id: \$id) {
        data {
          id
          attributes {
            name
            done
          }
        }
      }
    }
    """;
    String updateTodo = """
    mutation updateTodo(\$id: ID!, \$done: Boolean, \$name: String) {
      updateTodo(id: \$id, data: { done: \$done, name: \$name}) {
        data {
          id
          attributes {
            name
            done
          }
        }
      }
    }
    """;
    String deleteTodo = """
    mutation deleteTodo(\$id: ID!) {
      deleteTodo(id: \$id) {
        data {
          id
          attributes {
            name
            done
          }
        }
      }
    }
    """;
    class ViewTodo extends StatefulWidget {
      final id;
      final refresh;
      const ViewTodo({Key? key, @required this.id, @required this.refresh})
          : super(key: key);
      @override
      ViewTodoState createState() =>
          ViewTodoState(id: this.id, refresh: this.refresh);
    }
    class ViewTodoState extends State<ViewTodo> {
      late final id;
      late final refresh;
      ViewTodoState({Key? key, @required this.id, this.refresh});
      var editMode = false;
      var myController;
      bool? done;
      @override
      Widget build(BuildContext context) {
        return GraphQLProvider(
            client: GraphQLConfiguration.clientToQuery(),
            child: Query(
                options: QueryOptions(
                    document: gql(readTodo),
                    variables: {'id': id},
                    pollInterval: const Duration(seconds: 0)),
                builder: (QueryResult result,
                    {VoidCallback? refetch, FetchMore? fetchMore}) {
                  if (result.hasException) {
                    return Text(result.exception.toString());
                  }
                  if (result.isLoading) {
                    return const Scaffold(body: Center(child: Text('Loading')));
                  }
                  // it can be either Map or List
                  var todo = result.data?["todo"];
                  done = todo\["data"\]["attributes"]["done"];
                  myController = TextEditingController(
                      text: todo\["data"\]["attributes"]["name"].toString());
                  return Scaffold(
                      appBar: AppBar(
                          elevation: 0,
                          automaticallyImplyLeading: false,
                          backgroundColor: Colors.blue,
                          flexibleSpace: SafeArea(
                              child: Container(
                                  padding: const EdgeInsets.only(
                                      right: 16, top: 4, bottom: 4, left: 0),
                                  child: Row(children: <Widget>[
                                    IconButton(
                                      onPressed: () {
                                        Navigator.pop(context);
                                      },
                                      icon: const Icon(
                                        Icons.arrow_back,
                                        color: Colors.white,
                                      ),
                                    ),
                                    const SizedBox(
                                      width: 20,
                                    ),
                                    const Text(
                                      "View Todo",
                                      style: TextStyle(
                                          fontSize: 25,
                                          fontWeight: FontWeight.bold,
                                          color: Colors.white),
                                    ),
                                  ])))),
                      body: Container(
                        padding: const EdgeInsets.all(12),
                        margin: const EdgeInsets.all(8),
                        decoration: BoxDecoration(
                            borderRadius: BorderRadius.circular(9),
                            color: Colors.blue),
                        width: double.infinity,
                        height: 200,
                        child: editMode
                            ? Column(
                                children: [
                                  Container(
                                      width: double.infinity,
                                      padding:
                                          const EdgeInsets.fromLTRB(0, 0, 0, 4),
                                      child: const Text("Todo:",
                                          textAlign: TextAlign.left,
                                          style: TextStyle(
                                            color: Colors.white,
                                            fontSize: 20,
                                          ))),
                                  TextField(
                                    controller: myController,
                                    decoration: const InputDecoration(
                                        border: OutlineInputBorder(
                                            borderSide: BorderSide(
                                                width: 1, color: Colors.white)),
                                        hintText: 'Add todo'),
                                  ),
                                  Row(
                                      crossAxisAlignment: CrossAxisAlignment.center,
                                      children: [
                                        Container(
                                            padding: const EdgeInsets.fromLTRB(
                                                0, 0, 0, 4),
                                            child: const Text("Done:",
                                                textAlign: TextAlign.left,
                                                style: TextStyle(
                                                  color: Colors.white,
                                                  fontSize: 20,
                                                ))),
                                        StatefulBuilder(builder:
                                            (BuildContext context,
                                                StateSetter setState) {
                                          return Checkbox(
                                            value: done,
                                            onChanged: (value) {
                                              setState(() {
                                                done = value;
                                              });
                                            },
                                          );
                                        }),
                                      ])
                                ],
                              )
                            : Column(
                                crossAxisAlignment: CrossAxisAlignment.center,
                                children: [
                                  Row(
                                    children: [
                                      Container(
                                        padding:
                                            const EdgeInsets.fromLTRB(0, 0, 0, 4),
                                        child: const Text("Todo:",
                                            textAlign: TextAlign.left,
                                            style: TextStyle(
                                              color: Colors.white,
                                              fontSize: 20,
                                            )),
                                      ),
                                      const SizedBox(
                                        width: 15,
                                      ),
                                      Container(
                                          padding:
                                              const EdgeInsets.fromLTRB(0, 0, 0, 4),
                                          child: Text(
                                              todo\["data"\]["attributes"]["name"]
                                                  .toString(),
                                              textAlign: TextAlign.left,
                                              style: const TextStyle(
                                                  color: Colors.white,
                                                  fontSize: 20,
                                                  fontWeight: FontWeight.bold)))
                                    ],
                                  ),
                                  const SizedBox(
                                    height: 10,
                                  ),
                                  Row(
                                    children: [
                                      const Text("Done:",
                                          textAlign: TextAlign.left,
                                          style: TextStyle(
                                            color: Colors.white,
                                            fontSize: 20,
                                          )),
                                      const SizedBox(
                                        width: 15,
                                      ),
                                      Text(
                                          todo\["data"\]["attributes"]["done"]
                                              .toString(),
                                          textAlign: TextAlign.left,
                                          style: const TextStyle(
                                              color: Colors.white,
                                              fontSize: 20,
                                              fontWeight: FontWeight.bold))
                                    ],
                                  ),
                                ],
                              ),
                      ),
                      floatingActionButton: !editMode
                          ? Mutation(
                              options: MutationOptions(
                                document: gql(deleteTodo),
                                update:
                                    (GraphQLDataProxy cache, QueryResult? result) {
                                  return cache;
                                },
                                onCompleted: (dynamic resultData) {
                                  refresh();
                                  ScaffoldMessenger.of(context).showSnackBar(
                                      const SnackBar(content: Text('Done.')));
                                  Navigator.pop(context);
                                },
                              ),
                              builder:
                                  (RunMutation runMutation, QueryResult? result) {
                                return Column(
                                    crossAxisAlignment: CrossAxisAlignment.end,
                                    mainAxisAlignment: MainAxisAlignment.end,
                                    children: [
                                      FloatingActionButton(
                                        backgroundColor: Colors.red,
                                        foregroundColor: Colors.white,
                                        heroTag: null,
                                        child: const Icon(Icons.delete),
                                        onPressed: () {
                                          runMutation({'id': id});
                                          ScaffoldMessenger.of(context)
                                              .showSnackBar(const SnackBar(
                                                  content:
                                                      Text('Deleting todo...')));
                                        },
                                      ),
                                      const SizedBox(
                                        height: 10,
                                      ),
                                      FloatingActionButton(
                                        foregroundColor: Colors.white,
                                        backgroundColor: Colors.blue,
                                        onPressed: () {
                                          setState(() {
                                            editMode = true;
                                          });
                                        },
                                        tooltip: 'Edit todo',
                                        child: const Icon(Icons.edit),
                                      )
                                    ]);
                              })
                          : Mutation(
                              options: MutationOptions(
                                document: gql(updateTodo),
                                update:
                                    (GraphQLDataProxy cache, QueryResult? result) {
                                  return cache;
                                },
                                onCompleted: (dynamic resultData) {
                                  refresh();
                                  refetch!();
                                  ScaffoldMessenger.of(context).showSnackBar(
                                      const SnackBar(content: Text('Done.')));
                                },
                              ),
                              builder: (
                                RunMutation runMutation,
                                QueryResult? result,
                              ) {
                                return Column(
                                    crossAxisAlignment: CrossAxisAlignment.end,
                                    mainAxisAlignment: MainAxisAlignment.end,
                                    children: [
                                      Padding(
                                          padding:
                                              const EdgeInsets.fromLTRB(0, 0, 0, 5),
                                          child: FloatingActionButton(
                                            foregroundColor: Colors.white,
                                            backgroundColor: Colors.red,
                                            heroTag: null,
                                            child: const Icon(Icons.cancel),
                                            onPressed: () {
                                              setState(() {
                                                editMode = false;
                                              });
                                            },
                                          )),
                                      FloatingActionButton(
                                        foregroundColor: Colors.white,
                                        backgroundColor: Colors.green,
                                        heroTag: null,
                                        child: const Icon(Icons.save),
                                        onPressed: () {
                                          ScaffoldMessenger.of(context)
                                              .showSnackBar(const SnackBar(
                                                  content:
                                                      Text('Updating todo...')));
                                          runMutation({
                                            'id': id,
                                            'name': myController.text,
                                            'done': done
                                          });
                                          setState(() {
                                            editMode = false;
                                          });
                                        },
                                      )
                                    ]);
                              }));
                }));
      }
    }

We have three string variables set readTodo, updateTodo, and deleteTodo.

• The readTodo is a query data to return a todo by its id.
• The updateTodo is a mutation to update a todo using its id with new done and name values.
• The deleteTodo is also a mutation that deletes a todo.

Notice that the ViewTodo is a stateful widget and manages its State in the ViewTodoState widget. Every variable inside the ViewTodoState widget is a state variable that can be updated during the widget's lifetime.

The constructor is set to accept the Todo's id and a refresh function. In the ViewTodoState widget, see that we have an editMode boolean variable. This variable sets the edit mode of the widget. We did this to toggle text fields we can use to edit this widget without the need for another widget screen.

The myController is a text controller for a text field when editing the Todo in an edit mode. We use it to get the value typed in a TextField.

The bool? done; is used to hold the done field of the todo.

In the build method, we enclosed the whole widget in the tree with the Query widget. It calls the readTodo on start-up and renders the name and done fields of the Todo in the UI.

We used a ternary operator to check when the editMode is active and render text field and the checkbox to edit the Todo. If there is no edit mode, the todo details are rendered on Text widgets. Also, we are using the editMode to render FloatingActionButtons based on the current model.

If there is an edit mode, the save and cancel FloatingActionButtons will show. The save FloatingActionButton will save the edited Todo. It will collect the name value from TextField and collect the done value from the State of the CheckBox. Then, it will call the runMutation with the values.

There is an onCompleted function of the Mutation object enclosing the edit section of the save and cancel FloatingActionButton.

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  onCompleted: (dynamic resultData) {
      refresh();
      refetch!();
      ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Done.')));
    },

We call the refresh method to refresh the list of todos in the TodoList and the refetch method from the Query widget to refresh this ViewTodo widget because the current Todo has been modified.

If there is no edit mode, the edit and delete FlatActionButton are shown. The edit FlatActionButton, when clicked, sets the editMode State to true. The delete FlatActionButton, when clicked, sends the deleteTodo to delete the current Todo.

In the onCompleted function of the Mutation widget that enclosed it, we called the refetch method and popped the ViewTodo widget off the screen because it was deleted and is no longer available.

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    onCompleted: (dynamic resultData) {
      refresh();
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Done.')));
      Navigator.pop(context);
      },

Let's code the CreateTodo screen.

CreateTodo

This method is where we create new todos. This screen will have a TextField where we can type in the name of the Todo to create. It will have a MaterialButton that will run a mutation when clicked.

Paste the below code to lib/screens/createTodo.dart:

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    import 'package:flutter/material.dart';
    import 'package:graphql_flutter/graphql_flutter.dart';
    import '../api/graphQLConfig.dart';
    String addTodo = """
    mutation createTodo(\$name: String, \$done: Boolean) {
      createTodo(data: { name: \$name, done: \$done}) {
        data {
          id
          attributes {
            name
            done
          }
        }
      }
    }
    """;
    class CreateTodo extends StatelessWidget {
      final myController = TextEditingController();
      final refresh;
      CreateTodo({Key? key, this.refresh}) : super(key: key);
      @override
      Widget build(BuildContext context) {
        return GraphQLProvider(
            client: GraphQLConfiguration.clientToQuery(),
            child: Mutation(
                options: MutationOptions(
                  document: gql(addTodo),
                  update: (GraphQLDataProxy cache, QueryResult? result) {
                    return cache;
                  },
                  onCompleted: (dynamic resultData) {
                    refresh!();
                    ScaffoldMessenger.of(context).showSnackBar(
                        const SnackBar(content: Text('New todo added.')));
                    Navigator.pop(context);
                  },
                ),
                builder: (
                    RunMutation runMutation,
                    QueryResult? result,
                    ) {
                  return Scaffold(
                      appBar: AppBar(
                        title: const Text("Create Todo"),
                      ),
                      body: Column(children: [
                        Container(
                            alignment: Alignment.centerLeft,
                            padding: const EdgeInsets.fromLTRB(10, 50, 10, 9),
                            child: TextField(
                              controller: myController,
                              decoration: const InputDecoration(
                                  border: OutlineInputBorder(),
                                  hintText: 'Add todo'),
                            )),
                        Row(children: [
                          Expanded(
                              child: Padding(
                                  padding: const EdgeInsets.all(10),
                                  child: MaterialButton(
                                    onPressed: () {
                                        runMutation({
                                          'name': myController.text,
                                          'done': false
                                        });

                                      ScaffoldMessenger.of(context).showSnackBar(
                                          const SnackBar(
                                              content: Text('Adding new todo...')));
                                    },
                                    color: Colors.blue,
                                    padding: const EdgeInsets.all(17),
                                    child: const Text(
                                      "Add",
                                      style: TextStyle(
                                          fontWeight: FontWeight.bold,
                                          color: Colors.white,
                                          fontSize: 20),
                                    ),
                                  )))
                        ])
                      ]));
                }));;
      }
    }

Notice that we have a createTodo mutation set. This mutation string will create a new todo in our Strapi.

The CreateTodo is a stateless widget, and it manages no state. The constructor accepts the refresh function passed to it and stores in it the refresh variable.

myController is a TextEditingController used to manipulate TextFields. We wrap its widget tree in GraphQLProvider and Mutation widgets. The document function will run the gql(createTodo) function call when the runMutation argument in its builder function is called.

In the UI, a TextField is rendered. This is where the new todo name is typed. The myController is set to the TextField. This will enable us to use the myController to get the value of the TextField.

The MaterialButton has an onPressed event registered to it. Its handler will be called when the button is pressed. This will retrieve the value in the TextField using the myController. It will call the runMutation function passing in the value in the TextField. This will run the createTodo mutation creating a new todo in our Strapi backend.

The onCompleted function will be called when the mutation completes:

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    onCompleted: (dynamic resultData) {
      refresh!();
      ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('New todo added.')));
      Navigator.pop(context);
    },

The refresh function passed to the CreateTodo widget from the TodoList widget is called, so the todos list in the TodoList widget is updated to display our newly added todo item.

Testing the App

Now let’s test our application to ensure that everything is working. If you run the application, you should be able to add, update, edit and delete a Todo as in the demo below

References

• graphql_flutter: ^5.0.2
• How to Use GraphQL in Flutter
• How to set up Android emulator proxy settings
• Set up Android Emulator networking
• Building a simple application with Flutter and GraphQL
• How to point to localhost:8000 with the Dart http package in Flutter?
• Connecting Flutter application to Localhost
• Strapi GraphQL API
• Strapi Setup and Deployment

Conclusion

From this tutorial, we learn how to create a Strapi project, build collections using its admin dashboard and set up Graphql endpoints.

We created a simple Todo app in Flutter to show how we can consume the Strapi GraphQL endpoints from a mobile app.

Strapi is straightforward, to begin with, and provides an easy-to-understand doc. It can connect with any client, mobile, web, or desktop. Feel free to check out other quick guides Strapi Integrations to get started.

Code

You can find the full working code of the Flutter application this To-Do App with Strapi GraphQL Plugin and Flutter repository