react-native-firebase/docs/v2/redux.md

126 lines
2.9 KiB
Markdown

# Usage with Redux
Although RNFirebase usage requires a React Native environment, it isn't tightly coupled which allows for full flexibility
when it comes to integrating with other modules such a [`react-redux`](https://github.com/reactjs/react-redux). If you wish to use
a Redux library designed for Firebase, we suggest taking a look at [`react-redux-firebase`](http://docs.react-redux-firebase.com/history/v2.0.0/docs/recipes/react-native.html)
for implementation with this module.
## Standalone integration
Although the following example works for a basic redux setup, it may differ when integrating with other redux middleware.
Imagine a simple TODO app, with redux we're able to abstract the Firebase logic out of components which allows for greater
testability and maintainability.
?> We use [`redux-thunk`](https://github.com/gaearon/redux-thunk) to provide async actions.
### Action Creators
```js
// Actions
export const subscribe = () => {
return (dispatch) => {
firebase.database().ref('todos').on('value', (snapshot) => {
const todos = [];
snapshot.forEach((childSnapshot) => {
todos.push({
id: childSnapshot.key,
...(childSnapshot.val()),
})
})
dispatch({
type: 'TODO_UPDATE',
todos,
})
})
}
}
// Methods
export const addTodo = text => {
firebase.database().ref('todos').push({
text,
visible: true,
})
}
export const completeTodo = id => {
firebase.database().ref(`todos/${id}`).update({
visible: false,
})
}
```
Instead of creating multiple actions which the reducers handle, we instead subscribe to the database ref and on any changes,
send a single action for the reducers to handle with the data which is constantly updating.
### Reducers
Our reducer now becomes really simple, as we're able to simply update the reducers state with whatever data has been returned
from our Firebase subscription.
```js
const todos = (state = {}, action) => {
switch (action.type) {
case 'TODO_UPDATE':
return { ...action.todos };
}
return state;
}
export default todos;
```
### Component
We can now easily subscribe to the todos in redux state and get live updates when Firebase updates.
```js
import React from 'react';
import { FlatList } from 'react-native';
import { connect } from 'react-redux';
import { subscribe, addTodo, completeTodo } from '../actions/TodoActions.js';
...
class Todos extends React.Component {
componentDidMount() {
this.props.dispatch(
subscribe()
);
}
onComplete = (id) => {
this.props.dispatch(
completeTodo(id)
);
};
onAdd = (text) => {
this.props.dispatch(
addTodo(text)
);
};
render() {
return (
<FlatList
data={this.props.todos}
...
/>
);
}
}
function mapStateToProps(state) {
return {
todos: state.todos,
};
}
export default connect(mapStateToProps)(Todos);
```