Strapi is a headless CMS that allows you to easily build customizable backend services. You can integrate Strapi applications with any type of frontend and can deploy the application to the cloud.

This tutorial guides you through the process of creating a simple React-native to-do app with Strapi as your backend. You will be able to create, edit, and delete to-dos on a per-user basis by interacting with the Strapi's REST API.

Note: This tutorial assumes that you already have an instance of Strapi up and running and created a test user. If you don’t, read the Getting Started guide.

The sample app is available on Github.

Setting up the Backend

Firstly, we’ll need to create a Strapi project with the command below:

    npx create-strapi-app@latest strapi-backend

After creating the project, Strapi will automatically start a development server. We can always run the development server ourselves by opening the root folder in the terminal and running the yarn develop command:

    yarn develop

We’ll need to create a new “todo” content type. For that, we need to access our Content-Type Builder and click on + Create new collection type.

Now that we have successfully created our new Content-Type, we need to add some fields to it:

• title (Text, Short, required): The title of the TODO.
• description (Text, Long, required): A quick summary of the TODO.
• finished (Boolean, default: false): If the TODO was finished.
• owner (Relation, required): The User (User-Permissions) that the TODO belongs to.

When you successfully have added the fields to your Content-Type, it should look like this:

After saving the changes, we need to register the endpoints for the ToDo collection. The endpoints allows our react-native app to interact with the collection. To register the endpoints we need to:

1. Navigate to Settings → Users & Permission plugin → Roles.
2. Click on Authenticated.
3. Toggle the Todo dropdown under Permissions.
4. Tick Select All.
5. Click Save.

Creating the Mobile App

Now that we have our API set up, we can concentrate on our mobile app. I suggest checking out React native’s Getting Started guide if you aren’t familiar with React-native. We’ll have to initialize a new React-native project by running the React-native CLI.

    react-native init TodoApp

Running this command will create a new directory with the specified app name that will be the root of your project. In the base directory of your project, you’ll have to create the following folder structure:

1
2
3
4
5
6
7
8
9
10
src
 |-- app
      |-- controllers
      |-- models
      |-- views
 |-- components
 |-- redux
       |-- actions
       |-- reducers
 |-- screens

Now that we have our project initialized, our structure optimized, and our backend running, we can add some packages to our app. We’ll use a predefined list of packages I found. There may be better alternatives, but you are free to decide this for yourself!

The Interface

• react-native-paper: A set of components following Google’s Material Design guidelines
• react-native-vector-icons: Used by react-native-paper to display a gigantic set of icons that fit your needs.
• react-navigation: A library for creating in-app navigation and handling navigation intents. It also provides integration with react-native-paper by providing a material themed bottom tab bar.
• react-native-gesture-handler: Required by react-navigation to work properly.

State Management

• redux: Redux is a library for handling global state and modification.
• react-redux: Provides the components needed for redux to work with react-native.
• redux-persist: Enables you to save and persist your state locally on the device. It is especially handy for authentication flows.
• async-storage: Asynchronous on-device storage

To add the packages, install them with yarn:

    yarn add react-native-paper react-native-vector-icons react-navigation redux react-redux redux-persist @react-native-community/async-storage react-native-gesture-handler

Creating the Models and Controllers

Before getting to the interface of the app, we’ll create a model for our TODO. To do so, create a new file in ./src/app/models/TodoModel.js. Since this file contains the model for the Content-Type we have created earlier, the fields need to be exactly the same.

1. Create a ./src/app/models/TodoModel.js file containing the following code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
    // TodoModel.js
    
    /**
     * TODO Model as defined in Strapi
     */
    
    import {edit, save, dismiss} from '../controllers/TodoController';
    
    class TodoModel {
      constructor(user, title, description, finished = false, id = undefined) {
        this.user = user;
        this.title = title;
        this.description = description;
        this.finished = finished;
        this.id = id;
        // save function adds id property later
      }
    
      async save() {
        // save the todo to Strapi
        const id = await save(this);
    
        // should no id be returned throw an error
        if (!id) {
          throw new Error('Todo could not be saved');
        }
    
        // set id and return true
        this.id = id;
        return true;
      }
    
      async edit() {
        if (!this.id) {
          throw new Error('Cannot edit TODO before it was saved.');
        }
    
        const edited = await edit(this);
    
        // check if the edit returned false
        if (!edited) {
          throw new Error('Todo could not be edited.');
        }
    
        return true;
      }
    
      async dismiss() {
        if (!this.id) {
          throw new Error('Cannot delete TODO before it was saved.');
        }
    
        const dismissed = await dismiss(this);
    
        // check if the dismiss returned false
        if (!dismissed) {
          throw new Error('Todo could not be deleted.');
        }
    
        return true;
      }
    }
    
    export default TodoModel;

2. Do the same for our User Content-Type from the User-Permissions plugin in Strapi. Create a file in ./src/app/models/UserModel.js containing the following code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
    // UserModel.js
    
    /**
     * User model as defined in Strapi
     */
    
    import {login, logout} from '../controllers/UserController';
    
    class UserModel {
      constructor(identifier, password) {
        this.identifier = identifier;
        this.password = password;
      }
    
      async login() {
        const result = await login(this);
    
        if (!result) {
          throw new Error('Unable to login user.');
        }
    
        return true;
      }
    
      async logout() {
        const result = await logout(this);
    
        if (!result) {
          throw new Error('Unable to logout user.');
        }
    
        return true;
      }
    }
    
    export default UserModel;

Now that we have coded our models, you may notice that we imported a file we haven’t created yet, so let’s create the two needed files:

• ./src/app/controllers/UserController.js
• ./src/app/controllers/TodoController.js

These file are our controllers where we hold our app logic that will be executed when we call our model functions.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
    // TodoController.js
    
    import {store} from '../../redux/Store';
    
    /**
     * if you have an instance of Strapi running on your local
     * machine:
     *
     * 1. Run `adb reverse tcp:8163 tcp:8163` (only on android)
     *
     * 2. You have to change the access IP from localhost
     * to the IP of the machine Strapi is running on.
     */
    const url = 'http://localhost:1337/todos';
    
    /**
     * add a todo to Strapi
     */
    export const save = async todo => {
      const requestBody = JSON.stringify({
        title: todo.title,
        description: todo.description,
        finished: todo.finished,
        user: todo.user.id,
      });
    
      const requestConfig = {
        method: 'POST',
        headers: {
          Authorization: `Bearer ${store.getState().jwt}`,
          'Content-Type': 'application/json',
        },
        body: requestBody,
      };
    
      const response = await fetch(url, requestConfig);
    
      const json = await response.json();
    
      if (json.error) {
        return null;
      }
    
      return json._id;
    };
    
    /**
     * add a todo to Strapi
     */
    export const edit = async todo => {
      const requestBody = JSON.stringify({
        title: todo.title,
        description: todo.description,
        due: todo.due,
        finished: todo.finished ? 1 : 0,
        user: todo.user.id,
      });
    
      const requestConfig = {
        method: 'PUT',
        headers: {Authorization: `Bearer ${store.getState().jwt}`},
        body: requestBody,
      };
    
      const response = await fetch(`${url}/${todo.id}`, requestConfig);
      const json = await response.json();
    
      if (json.error) {
        return false;
      }
    
      return true;
    };
    
    /**
     * delete a todo from Strapi
     */
    export const dismiss = async todo => {
      const response = await fetch(`${url}/${todo.id}`, {
        headers: {Authorization: `Bearer ${store.getState().jwt}`},
      });
    
      const json = response.json();
    
      if (json.error) {
        return false;
      }
    
      return true;
    };

Now, the second controller:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
    // UserController.js
    
    import {saveUser, deleteUser} from '../../redux/actions/UserActions';
    
    /**
     * if you have an instance of Strapi running on your local
     * machine:
     *
     * 1. Run `adb reverse tcp:8163 tcp:8163` (only on android)
     *
     * 2. You have to change the access IP from localhost
     * to the IP of the machine Strapi is running on.
     */
    const url = 'http://192.168.0.57:1337';
    
    /**
     * @param {UserModel} user
     */
    export const login = async user => {
      const requestConfig = {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({
          identifier: user.identifier,
          password: user.password,
        }),
      };
    
      try {
        const response = await fetch(`${url}/auth/local`, requestConfig);
        const json = await response.json();
    
        if (json.error) {
          return false;
        }
    
        saveUser(json.jwt, json.user);
    
        return true;
      } catch (err) {
        alert(err);
        return false;
      }
    };
    
    /**
     * @param {UserModel} user
     */
    export const logout = async user => {
      deleteUser();
    };

As seen, we call our redux store at the end of the UserController.login() and UserController.logout(). It will make more sense in a few moments.

Creating the Redux Store

To be able to update our UI, we need to create a Redux store. This store will hold our user data and be persisted if modified. Amazing, right?

Steps

Create the following files:

• ./src/redux/Store.js
• ./src/redux/reducers/UserReducer.js
• ./src/redux/actions/UserActions.js

Now that we have created the files, we can start creating our store logic. The logic for each store identity is held in their so-called reducer.

The reducer can receive an action; this action has a type and an optional payload that you can define on a per-request basis. We’ll need two types of actions that’ll be USER_SAVE and USER_DELETE that symbolize respective user log in -/out’s. We will not implement USER_DELETE though.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
    // UserReducer.js
    
    const defaultState = {
      jwt: null,
      user: null,
    };
    
    /**
     * This is a reducer, a pure function with (state, action) => state signature.
     * It describes how an action transforms the state into the next state.
     *
     * The shape of the state is up to you: it can be a primitive, an array, an object,
     * or even an Immutable.js data structure. The only important part is that you should
     * not mutate the state object, but return a new object if the state changes.
     *
     * In this example, we use a `switch` statement and strings, but you can use a helper that
     * follows a different convention (such as function maps) if it makes sense for your
     * project.
     */
    const UserReducer = (state = defaultState, action) => {
      switch (action.type) {
        case 'USER_SAVE': {
          return {
            ...state,
            ...{jwt: action.payload.jwt, user: action.payload.user},
          };
        }
    
        case 'USER_DELETE': {
          return defaultState;
        }
    
        default:
          return defaultState;
      }
    };
    
    export default UserReducer;

To call this reducer, we will access the previously created UserActions.js file. That holds two actions: saveUser() and deleteUser().

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
    // UserActions.js
    
    import {store} from '../Store';
    
    // The only way to mutate the internal state is to dispatch an action.
    // The actions can be serialized, logged or stored and later replayed.
    export const saveUser = (jwt, user) => {
      store.dispatch({
        type: 'USER_SAVE',
        payload: {
          jwt,
          user,
        },
      });
    };
    
    export const deleteUser = () => {
      store.dispatch({type: 'USER_DELETE'});
    };

And lastly, we have to code our Store.js file. This file not only includes the reducer but also provides the persistence via the previously installed redux-persist library.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
    // Store.js
    
    import {createStore} from 'redux';
    import {persistStore, persistReducer} from 'redux-persist';
    import AsyncStorage from '@react-native-community/async-storage';
    
    import rootReducer from '../redux/reducers/UserReducer';
    
    const persistConfig = {
      key: 'root',
      storage: AsyncStorage,
    };
    
    const persistedReducer = persistReducer(persistConfig, rootReducer);
    
    // Create a Redux store holding the state of your app.
    // Its API is { subscribe, dispatch, getState }.
    const createdStore = createStore(persistedReducer);
    const createdPersistor = persistStore(createdStore);
    
    export const store = createdStore;
    export const persistor = createdPersistor;

Just one more step and your app is redux-ready! Add the PersistorGate and Provider components to your App.js file.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
    // App.js
    
    import React from 'react';
    import {PersistGate} from 'redux-persist/integration/react';
    import {Provider} from 'react-redux';
    import {store, persistor} from './src/redux/Store';
    
    const App = () => {
      return (
        <Provider store={store}>
          <PersistGate loading={null} persistor={persistor} />
        </Provider>
      );
    };
    
    export default App;

Building the Navigation

To build our screens, we'll use the previously-installed react-navigation package. We’ll have to create a bunch of files; hope you are ready to get your hands dirty!

Screens

• ./src/screens/Overview.js
• ./src/screens/Login.js

Navigation

• ./src/components/navigation/Authentication.js

Once created, fill all Screen files with mock up content so you can distinguish what screen you are currently on.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
    // Overview.js & Login.js
    
    import React from 'react';
    import {View, StyleSheet} from 'react-native';
    import {Text} from 'react-native-paper';
    
    const SCREEN_NAME = props => {
      return (
        <View style={styles.base}>
          <Text style={styles.text}>SCREEN_NAME</Text>
        </View>
      );
    };
    
    const styles = StyleSheet.create({
      base: {
        flex: 1,
        alignContent: 'center',
        justifyContent: 'center',
      },
      text: {
        textAlign: 'center',
      },
    });
    
    export default SCREEN_NAME;

Note: Replace SCREEN_NAME with the name of the screen.

Building the Navigation’s Logic

Open up the file Authentication.js created in the last step and create a new SwitchNavigator via the createStackNavigator() method. We use the SwitchNavigator in combination with redux to redirect the user to the login page or the overview page depending on his authentication state.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
    // Authentication.js
    
    import React from 'react';
    
    // navigation components
    import {createSwitchNavigator, createAppContainer} from 'react-navigation';
    
    import Login from '../../screens/Login';
    import Overview from '../../screens/Overview';
    import {store} from '../../redux/Store';
    
    const Authentication = () => {
      const [route, setRoute] = React.useState(
        store.getState().jwt ? 'Overview' : 'Login',
      );
    
      const Navigator = createAppContainer(
        createSwitchNavigator(
          {
            Login: {
              screen: Login,
            },
            Overview: {
              screen: Overview,
            },
          },
          {
            initialRouteName: route,
          },
        ),
      );
    
      // on mount subscribe to store event
      React.useEffect(() => {
        store.subscribe(() => {
          setRoute(store.getState().jwt ? 'Overview' : 'Login');
        });
      }, []);
    
      return <Navigator />;
    };
    
    export default Authentication;

Including the Navigation into Our App

Import the navigation file into your App.js file and render it as a component. Also, add the Provider component of react-native-paper

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
    // App.js
    
    import React from 'react';
    import {Provider as PaperProvider} from 'react-native-paper';
    import {PersistGate} from 'redux-persist/integration/react';
    import {Provider} from 'react-redux';
    import {store, persistor} from './src/redux/Store';
    import Authentication from './src/components/navigation/Authentication';
    
    const App = () => {
      return (
        <Provider store={store}>
          <PersistGate loading={null} persistor={persistor}>
            <PaperProvider>
              <Authentication />
            </PaperProvider>
          </PersistGate>
        </Provider>
      );
    };
    
    export default App;

Now run your project and take a look at your device/emulator and you should see the following screen:

Coding and Styling the Login Screen

Our mockup screen is amazing but we need to add some functionality to it.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
    // Login.js
    
    import React from 'react';
    import {View, StyleSheet, StatusBar} from 'react-native';
    import {
      Headline,
      Paragraph,
      TextInput,
      Button,
      Snackbar,
      Portal,
    } from 'react-native-paper';
    import UserModel from '../app/models/UserModel';
    
    const Login = props => {
      const [identifier, setIdentifier] = React.useState('');
      const [password, setPassword] = React.useState('');
      const [visible, setVisible] = React.useState(false);
      const [loading, setLoading] = React.useState(false);
      const [error, setError] = React.useState(false);
    
      const validateInput = () => {
        let errors = false;
    
        if (!identifier || identifier.length === 0) {
          errors = true;
        }
    
        if (!password || password.length === 0) {
          errors = true;
        }
    
        return !errors;
      };
    
      const authenticateUser = async () => {
        if (validateInput()) {
          setLoading(true);
          const user = new UserModel(identifier, password);
    
          try {
            await user.login();
          } catch (err) {
            setError(err.message);
            setVisible(true);
            setLoading(false);
          }
        } else {
          setError('Please fill out all *required fields');
          setVisible(true);
          setLoading(false);
        }
      };
    
      return (
        <View style={styles.base}>
          <>
            <StatusBar backgroundColor="#ffffff" barStyle="dark-content" />
          </>
    
          <View style={styles.header}>
            <Headline style={styles.appTitle}>TodoApp</Headline>
            <Paragraph style={styles.appDesc}>
              Authenticate with Strapi to access the TodoApp.
            </Paragraph>
          </View>
    
          <>
            <View style={styles.divider} />
            <TextInput
              onChangeText={text => setIdentifier(text)}
              label="*Username or email"
              placeholder="*Username or email">
              {identifier}
            </TextInput>
          </>
    
          <>
            <View style={styles.divider} />
            <TextInput
              onChangeText={text => setPassword(text)}
              label="*Password"
              placeholder="*Password"
              secureTextEntry>
              {password}
            </TextInput>
          </>
    
          <>
            <View style={styles.divider} />
            <Button
              loading={loading}
              disabled={loading}
              style={styles.btn}
              onPress={() => authenticateUser()}
              mode="contained">
              Login
            </Button>
            <View style={styles.divider} />
            <View style={styles.divider} />
          </>
    
          <>
            {/**
             * We use a portal component to render
             * the snackbar on top of everything else
             * */}
            <Portal>
              <Snackbar visible={visible} onDismiss={() => setVisible(false)}>
                {error}
              </Snackbar>
            </Portal>
          </>
        </View>
      );
    };
    
    const styles = StyleSheet.create({
      base: {
        flex: 1,
        paddingLeft: 16,
        paddingRight: 16,
        alignContent: 'center',
        justifyContent: 'center',
        backgroundColor: '#ffffff',
      },
      divider: {
        height: 16,
      },
      headline: {
        fontSize: 30,
      },
      appDesc: {
        textAlign: 'center',
      },
      header: {
        padding: 32,
      },
      appTitle: {
        textAlign: 'center',
        fontSize: 35,
        lineHeight: 35,
        fontWeight: '700',
      },
      btn: {
        height: 50,
        paddingTop: 6,
      },
    });
    
    export default Login;

Try to login with a Strapi user and you’ll land directly on the overview page. Close the app, open it again, and you’ll see that you are directly accessing the overview screen. This is thanks to redux-persist loading your saved state and passing it to our SwitchNavigator in Authentication.js.

Coding and Styling the Overview Screen

Do you know what’s one of the greatest features of mobile development? Endless lists! We’re going to create a list that is created for our application. Since the length of such a list is undefined, the number of possible layouts is too.

List Component

Let's get started with our list component for which we’ll create a new ./src/components/TodoList.js file and paste the following:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
    // TodoList.js
    
    import React from 'react';
    import {View, StyleSheet} from 'react-native';
    import {
      Text,
      IconButton,
      ActivityIndicator,
      Button,
      Portal,
      Dialog,
      Paragraph,
      TextInput,
      HelperText,
      Divider,
    } from 'react-native-paper';
    import {FlatList} from 'react-native-gesture-handler';
    import {store} from '../../redux/Store';
    import TodoView from '../../app/views/TodoView';
    import TodoModel from '../../app/models/TodoModel';
    
    /**
     * the footer also acts as the load more
     * indicator.
     */
    export const TodoFooter = props => {
      return (
        <>
          {props.shouldLoadMore ? (
            <View style={styles.loaderView}>
              <ActivityIndicator animating />
            </View>
          ) : null}
        </>
      );
    };
    
    /**
     * This is our header for the list that also
     * includes the todo.add action.
     */
    export const TodoHeader = props => {
      const [error, setError] = React.useState('');
      const [title, setTitle] = React.useState('');
      const [visible, setVisible] = React.useState(false);
      const [description, setDescription] = React.useState('');
    
      const createTodoFromDialog = async () => {
        if (title.length === 0 || description.length === 0) {
          setError('Title and description are required.');
          return;
        }
    
        const user = store.getState().user;
        const todo = new TodoModel(user, title, description);
    
        try {
          await todo.save();
        } catch (err) {
          setError(err.message);
        }
    
        props.addTodo(todo);
      };
    
      return (
        <View style={styles.header}>
          <Text style={styles.text}>{props.text || "Your to do's"}</Text>
          <View style={styles.buttonFrame}>
            {!props.text ? (
              <Button
                onPress={() => setVisible(true)}
                style={{marginLeft: 16}}
                mode="outlined">
                Add a todo
              </Button>
            ) : null}
          </View>
    
          <Portal>
            <Dialog visible={visible} onDismiss={() => setVisible(false)}>
              <Dialog.Title>Create a new todo</Dialog.Title>
              <Dialog.Content>
                <Paragraph>
                  Adding a new todo will save to in Strapi so you can use it later.
                </Paragraph>
                <View style={styles.divider} />
                <TextInput
                  label="title"
                  placeholder="title"
                  onChangeText={text => {
                    setTitle(text);
                    setError(false);
                  }}>
                  {title}
                </TextInput>
                <View style={styles.divider} />
                <TextInput
                  label="description"
                  placeholder="description"
                  multiline={true}
                  numberOfLines={4}
                  onChangeText={text => {
                    setDescription(text);
                    setError(false);
                  }}>
                  {description}
                </TextInput>
                <HelperText type="error">{error}</HelperText>
              </Dialog.Content>
    
              <Dialog.Actions>
                <Button
                  onPress={() => {
                    setVisible(false);
                    setTitle('');
                    setDescription('');
                    setError('');
                  }}>
                  Cancel
                </Button>
                <Button onPress={() => createTodoFromDialog()}>Add</Button>
              </Dialog.Actions>
            </Dialog>
          </Portal>
        </View>
      );
    };
    
    /**
     * in case no todos were fetched on initial fetch
     * we can assume that there are none for this specific
     * user.
     */
    export const EmptyTodo = props => {
      const [error, setError] = React.useState('');
      const [title, setTitle] = React.useState('');
      const [visible, setVisible] = React.useState(false);
      const [description, setDescription] = React.useState('');
    
      const createTodoFromDialog = async () => {
        if (title.length === 0 || description.length === 0) {
          setError('Title and description are required.');
          return;
        }
    
        const user = store.getState().user;
        const todo = new TodoModel(user, title, description);
    
        try {
          await todo.save();
        } catch (err) {
          setError(err.message);
        }
    
        props.addTodo(todo);
      };
    
      return (
        <View style={styles.emptyBase}>
          <TodoHeader text={'Pretty empty here ..'} />
          <Button
            onPress={() => setVisible(true)}
            style={styles.btn}
            mode="contained">
            Create a new todo
          </Button>
    
          <Portal>
            <Dialog visible={visible} onDismiss={() => setVisible(false)}>
              <Dialog.Title>Create a new todo</Dialog.Title>
              <Dialog.Content>
                <Paragraph>
                  Adding a new todo will save to in Strapi so you can use it later.
                </Paragraph>
                <View style={styles.divider} />
                <TextInput
                  label="title"
                  placeholder="title"
                  onChangeText={text => {
                    setTitle(text);
                    setError(false);
                  }}>
                  {title}
                </TextInput>
                <View style={styles.divider} />
                <TextInput
                  label="description"
                  placeholder="description"
                  multiline={true}
                  numberOfLines={4}
                  onChangeText={text => {
                    setDescription(text);
                    setError(false);
                  }}>
                  {description}
                </TextInput>
                <HelperText type="error">{error}</HelperText>
              </Dialog.Content>
    
              <Dialog.Actions>
                <Button
                  onPress={() => {
                    setVisible(false);
                    setTitle('');
                    setDescription('');
                    setError('');
                  }}>
                  Cancel
                </Button>
                <Button onPress={() => createTodoFromDialog()}>Add</Button>
              </Dialog.Actions>
            </Dialog>
          </Portal>
        </View>
      );
    };
    
    /**
     * the main list component holding all of the loading
     * and pagination logic.
     */
    export const TodoList = props => {
      const [data, setData] = React.useState([]);
      const [limit] = React.useState(10);
      const [start, setStart] = React.useState(0);
      const [loading, setLoading] = React.useState(true);
      const [loadingMore, setLoadingMore] = React.useState(true);
      const [shouldLoadMore, setShouldLoadMore] = React.useState(true);
    
      /**
       * get the data from the server in a paginated manner
       *
       * 1. should no data be present start the normal loading
       * animation.
       *
       * 2. should data be present start the loading more
       * animation.
       */
      const getTodosForUser = React.useCallback(async () => {
        if (!shouldLoadMore) {
          return;
        }
    
        if (!loading && data.length === 0) {
          setLoading(true);
        }
    
        if (!loadingMore && data.length > 0) {
          setLoadingMore(true);
        }
    
        const url = `http://192.168.0.57:1337/todos?_start=${start}&_limit=${limit}`;
        const jwt = store.getState().jwt;
        const response = await fetch(url, {
          headers: {Authorization: `Bearer ${jwt}`},
        });
        const json = await response.json();
    
        if (json.length < 10) {
          setShouldLoadMore(false);
        } else {
          setStart(start + limit);
        }
    
        setData([...data, ...json]);
        setLoading(false);
        setLoadingMore(false);
      }, [data, limit, loading, loadingMore, shouldLoadMore, start]);
    
      /**
       * saves a new todo to the server by creating a new TodoModel
       * from the dialog data and calling Todo.save()
       */
      const addTodo = todo => {
        const {title, description, finished, user, id} = todo;
        setData([...data, ...[{title, description, finished, user, id}]]);
      };
    
      /**
       * callback method for the todo view. Deletes a todo from the list
       * after it has been deleted from the server.
       */
      const removeTodo = id => {
        setData(data.filter(item => item.id !== id));
      };
    
      React.useEffect(() => {
        getTodosForUser();
      }, [getTodosForUser]);
    
      if (loading) {
        return (
          <View style={styles.loaderBase}>
            <ActivityIndicator animating size="large" />
          </View>
        );
      }
    
      if (!shouldLoadMore && !loading && !loadingMore && data.length === 0) {
        return <EmptyTodo addTodo={addTodo} />;
      }
    
      return (
        <>
          <FlatList
            style={styles.base}
            data={data}
            ItemSeparatorComponent={() => <Divider />}
            ListHeaderComponent={() => <TodoHeader addTodo={addTodo} />}
            ListFooterComponent={() => (
              <TodoFooter shouldLoadMore={shouldLoadMore} />
            )}
            onEndReachedThreshold={0.5}
            onEndReached={() => getTodosForUser()}
            renderItem={({item, index}) => (
              <TodoView removeTodo={removeTodo} item={item} index={index} />
            )}
          />
        </>
      );
    };
    
    const styles = StyleSheet.create({
      base: {
        flex: 1,
        backgroundColor: '#fff',
      },
      emptyBase: {
        flex: 1,
        backgroundColor: '#fff',
      },
      text: {
        fontSize: 35,
        lineHeight: 35,
        fontWeight: '700',
        padding: 32,
        paddingLeft: 16,
      },
      header: {
        flexDirection: 'row',
        alignContent: 'center',
      },
      btn: {
        height: 50,
        paddingTop: 6,
        marginLeft: 16,
        marginRight: 16,
      },
      loaderBase: {
        padding: 16,
        alignContent: 'center',
        justifyContent: 'center',
        flex: 1,
      },
      divider: {
        height: 16,
      },
      buttonFrame: {
        justifyContent: 'center',
      },
    });