Django RN demo app: fix some issues picked up during Django backend cleanup (#217)

Co-authored-by: Steven Ontong <steven@journeyapps.com>

Author: kobiebotha

.changeset/eighty-pots-search.md

@@ -0,0 +1,5 @@
+---
+'django-react-native-todolist': minor
+---
+
+Use react hooks. Remove Mobx stores.

demos/django-react-native-todolist/README.md

@@ -25,12 +25,31 @@ Run on Android
 pnpm android
 ```
 
-## Set up Django Backend
+## Service Configuration
+
+This demo can be used with cloud or local services.
+
+### Local Services
+
+The [Self Hosting Demo](https://github.com/powersync-ja/self-host-demo) repository contains a Docker Compose Django backend demo which can be used with this client.
+See [instructions](https://github.com/powersync-ja/self-host-demo/blob/feature/django-backend/demos/django/README.md) for starting the backend locally.
+
+#### Android
+
+Note that Android requires port forwarding of local services. These can be configured with ADB as below:
+
+```bash
+adb reverse tcp:8080 tcp:8080 && adb reverse tcp:6061 tcp:6061
+```
+
+### Cloud Services
+
+#### Set up Django Backend
 
 This demo requires that you have the [PowerSync Django Backend: Todo List Demo](https://github.com/powersync-ja/powersync-django-backend-todolist-demo) running on your machine.
 Follow the guide in the README of the PowerSync Django Backend to set it up.
 
-## Set up PowerSync Instance
+#### Set up PowerSync Instance
 
 Create a new PowerSync instance, connecting to the database of the Supabase project.
 
@@ -42,11 +61,11 @@ bucket_definitions:
     # Separate bucket per todo list
     parameters: select id as list_id from lists where owner_id = token_parameters.user_id
     data:
-      - select * from api_list
-      - select * from api_todo
+      - select * from lists
+      - select * from todos
 ```
 
-## Configure The App
+#### Configure The App
 
 Copy the `AppConfig.template.ts` to a usable file
 

demos/django-react-native-todolist/app/_layout.tsx

@@ -1,5 +1,6 @@
 import { Stack } from 'expo-router';
-import React from 'react';
+import { PowerSyncContext } from '@powersync/react';
+import { useSystem } from '../library/stores/system';
 
 /**
  * This App uses a nested navigation stack.
@@ -16,14 +17,16 @@ import React from 'react';
  *          - Sign out. Psuedo view to initiate signout flow. Navigates back to first layer.
  */
 const HomeLayout = () => {
+  const system = useSystem();
   return (
-    <Stack screenOptions={{ headerTintColor: '#fff', headerStyle: { backgroundColor: '#2196f3' } }}>
-      <Stack.Screen name="signin" options={{ title: 'Supabase Login' }} />
-      <Stack.Screen name="register" options={{ title: 'Register' }} />
-
-      <Stack.Screen name="index" options={{ headerShown: false }} />
-      <Stack.Screen name="views" options={{ headerShown: false }} />
-    </Stack>
+    <PowerSyncContext.Provider value={system.powersync}>
+      <Stack screenOptions={{ headerTintColor: '#fff', headerStyle: { backgroundColor: '#2196f3' } }}>
+        <Stack.Screen name="signin" options={{ title: 'Supabase Login' }} />
+        <Stack.Screen name="register" options={{ title: 'Register' }} />
+        <Stack.Screen name="index" options={{ headerShown: false }} />
+        <Stack.Screen name="views" options={{ headerShown: false }} />
+      </Stack>
+    </PowerSyncContext.Provider>
   );
 };
 

demos/django-react-native-todolist/app/index.tsx

@@ -1,7 +1,5 @@
 import * as React from 'react';
 import { ActivityIndicator, View } from 'react-native';
-import { observer } from 'mobx-react-lite';
-import { useSystem } from '../library/stores/system';
 import { router } from 'expo-router';
 import Logger from 'js-logger';
 /**
@@ -10,34 +8,19 @@ import Logger from 'js-logger';
  *  - If one is present redirect to app views.
  *  - If not, reditect to login/register flow
  */
-const App = observer(() => {
-  const { djangoConnector } = useSystem();
-
+const App = () => {
   React.useEffect(() => {
     Logger.useDefaults();
     Logger.setLevel(Logger.DEBUG);
 
-    const getSession = async () => {
-      const response = await fetch('http://127.0.0.1:8000/api/get_session', {
-        method: 'GET',
-        headers: {
-          'Content-Type': 'application/json'
-        }
-      });
-      const data = await response.json();
-      if (data) {
-        router.replace('signin');
-      }
-    };
-
-    getSession();
+    setImmediate(() => router.replace('signin'));
   }, []);
 
   return (
     <View style={{ flex: 1, flexGrow: 1, alignContent: 'center', justifyContent: 'center' }}>
       <ActivityIndicator />
     </View>
   );
-});
+};
 
 export default App;

demos/django-react-native-todolist/app/register.tsx

@@ -6,6 +6,7 @@ import { useSystem } from '../library/stores/system';
 import { TextInputWidget } from '../library/widgets/TextInputWidget';
 import { SignInStyles } from './signin';
 import { Icon } from 'react-native-elements';
+import { router } from 'expo-router';
 
 export default function Register() {
   const { djangoConnector } = useSystem();
@@ -24,6 +25,7 @@ export default function Register() {
 
           <TextInputWidget
             placeholder="Username"
+            autoCapitalize="none"
             onChangeText={(value) => setCredentials({ ...credentials, username: value })}
           />
           <TextInputWidget
@@ -39,19 +41,8 @@ export default function Register() {
                 setLoading(true);
                 setError('');
                 try {
-                  // const { data, error } = await djangoConnector.supabaseClient.auth.signUp({
-                  //   email: credentials.username,
-                  //   password: credentials.password
-                  // });
-                  // if (error) {
-                  //   throw error;
-                  // }
-                  // if (data.session) {
-                  //   // djangoConnector.supabaseClient.auth.setSession(data.session);
-                  //   router.replace('views/todos/lists');
-                  // } else {
-                  //   router.replace('signin');
-                  // }
+                  await djangoConnector.register(credentials.username, credentials.password);
+                  router.replace('signin');
                 } catch (ex: any) {
                   console.error(ex);
                   setError(ex.message || 'Could not register');

demos/django-react-native-todolist/app/signin.tsx

@@ -24,12 +24,14 @@ export default function Signin() {
           <TextInputWidget
             style={SignInStyles.input}
             placeholder="Username"
+            autoCapitalize='none'
             onChangeText={(value) => setCredentials({ ...credentials, username: value.toLowerCase().trim() })}
           />
           <TextInputWidget
             style={SignInStyles.input}
             placeholder="Password"
             secureTextEntry={true}
+            autoCapitalize='none'
             onChangeText={(value) => setCredentials({ ...credentials, password: value })}
           />
           {error ? <Text style={{ color: 'red' }}>{error}</Text> : null}

demos/django-react-native-todolist/app/views/signout.tsx

@@ -5,12 +5,11 @@ import { router } from 'expo-router';
 import { useSystem } from '../../library/stores/system';
 
 export default function Signout() {
-  const { powersync, supabaseConnector } = useSystem();
+  const { powersync } = useSystem();
 
   React.useEffect(() => {
     (async () => {
       await powersync.disconnectAndClear();
-      await supabaseConnector.supabaseClient.auth.signOut();
       router.replace('signin');
     })();
   }, []);

demos/django-react-native-todolist/app/views/todos/edit/[id].tsx

@@ -1,76 +1,29 @@
-import * as React from 'react';
-import { StatusBar } from 'expo-status-bar';
-import { ScrollView, View, Text } from 'react-native';
-import { FAB } from 'react-native-elements';
-import { observer } from 'mobx-react-lite';
-import { Stack, useLocalSearchParams } from 'expo-router';
-import prompt from 'react-native-prompt-android';
+import { View, Text, ActivityIndicator } from 'react-native';
+import { useLocalSearchParams } from 'expo-router';
+import { useQuery } from '@powersync/react';
+import { ListTodosWidget } from '../../../../library/widgets/ListTodosWidget';
+import { LIST_TABLE, ListRecord } from '../../../../library/powersync/AppSchema';
 
-import { useSystem } from '../../../../library/stores/system';
-import { TodoItemWidget } from '../../../../library/widgets/TodoItemWidget';
-
-const TodoView = observer(() => {
-  const { listStore, todoStore } = useSystem();
+const TodoView = () => {
   const params = useLocalSearchParams<{ id: string }>();
 
   const id = params.id;
-  const listModel = React.useMemo(() => {
-    if (!id) {
-      return null;
-    }
-    const listModel = listStore.getById(id);
-
-    return listModel;
-  }, [id]);
+  const { data: result, isLoading } = useQuery<ListRecord>(`SELECT * FROM ${LIST_TABLE} WHERE id = ?`, [id]);
+  const listRecord = result[0];
 
-  if (!listModel) {
+  if (!listRecord && !isLoading) {
     return (
       <View>
-        <Text>No matching List found</Text>
+        <Text>No matching list found</Text>
       </View>
     );
   }
 
-  return (
-    <View style={{ flexGrow: 1 }}>
-      <Stack.Screen
-        options={{
-          title: listModel.record.name
-        }}
-      />
-      <FAB
-        style={{ zIndex: 99, bottom: 0 }}
-        icon={{ name: 'add', color: 'white' }}
-        size="small"
-        placement="right"
-        onPress={() => {
-          prompt(
-            'Add a new Todo',
-            '',
-            (text) => {
-              if (!text) {
-                return;
-              }
-
-              todoStore.createModel({
-                list_id: listModel.id,
-                description: text,
-                completed: false
-              });
-            },
-            { placeholder: 'Todo description', style: 'shimo' }
-          );
-        }}
-      />
-      <ScrollView style={{ maxHeight: '90%' }}>
-        {listModel.todos.map((t) => {
-          return <TodoItemWidget key={t.id} model={t} />;
-        })}
-      </ScrollView>
+  if (isLoading) {
+    return <ActivityIndicator />;
+  }
 
-      <StatusBar style={'light'} />
-    </View>
-  );
-});
+  return <ListTodosWidget record={listRecord} />;
+};
 
 export default TodoView;

demos/django-react-native-todolist/app/views/todos/lists.tsx

@@ -1,16 +1,18 @@
-import * as React from 'react';
 import { StatusBar } from 'expo-status-bar';
 import { ScrollView, View } from 'react-native';
 import { FAB } from 'react-native-elements';
-import { observer } from 'mobx-react-lite';
 import prompt from 'react-native-prompt-android';
 
 import { useSystem } from '../../../library/stores/system';
 import { ListItemWidget } from '../../../library/widgets/ListItemWidget';
 import { Stack } from 'expo-router';
+import { useQuery } from '@powersync/react';
+import { LIST_TABLE } from '../../../library/powersync/AppSchema';
+
+const App = () => {
+  const system = useSystem();
+  const { data: lists } = useQuery(`SELECT * FROM ${LIST_TABLE}`);
 
-const App = observer(() => {
-  const { listStore } = useSystem();
   return (
     <View style={{ flex: 1, flexGrow: 1 }}>
       <Stack.Screen
@@ -27,28 +29,31 @@ const App = observer(() => {
           prompt(
             'Add a new list',
             '',
-            (text) => {
+            async (text) => {
               if (!text) {
                 return;
               }
 
-              listStore.createModel({
-                name: text
-              });
+              const { userID } = await system.djangoConnector.fetchCredentials();
+
+              await system.powersync.execute(
+                `INSERT INTO ${LIST_TABLE} (id, created_at, name, owner_id) VALUES (uuid(), datetime(), ?, ?)`,
+                [text, userID]
+              );
             },
             { placeholder: 'List name', style: 'shimo' }
           );
         }}
       />
       <ScrollView style={{ maxHeight: '90%' }}>
-        {listStore.collection.map((t) => (
-          <ListItemWidget key={t.id} model={t} />
+        {lists.map((t) => (
+          <ListItemWidget key={t.id} record={t} />
         ))}
       </ScrollView>
 
       <StatusBar style={'light'} />
     </View>
   );
-});
+};
 
 export default App;

demos/django-react-native-todolist/database.sql

@@ -1 +1 @@
-create publication powersync for table api_list, api_todo;
+create publication powersync for table lists, todos;