OfflineWeb

Last updated 4 months ago

An offline storage extension that records analytics events in indexedDB when offline, and resyncs those events when back online. The extension adds a timestamp to each saved extension under the timeSaved key.

Like all offline storage extensions, this extension expects that you're already storing a connectivity flag in your app's state.

Installation

npm install --save @redux-beacon/offline-web

Import

import OfflineWeb from '@redux-beacon/offline-web';

Usage

Step 1

The first step is to track the connection status in your state. Here's an example of how you would do so using browser's in-built offline and online events:

const initialState = {
isConnected: true, // by default the app is assumed to have a connection
}
function reducer(state = initialState, action) {
switch (action.type) {
case 'UPDATE_CONNECTIVITY' {
return Object.assign({}, state, { isConnected: action.payload });
}
...
default:
return state;
}
}
window.addEventListener('offline', () => {
store.dispatch({
type: 'UPDATE_CONNECTIVITY',
payload: false,
});
});
window.addEventListener('online', () => {
store.dispatch({
type: 'UPDATE_CONNECTIVITY',
payload: true,
});
});

Step 2

Create a connectivity selector that accepts the state, and returns your app's connection status:

const isConnected = state => state.isConnected;

The connectivity selector should return a boolean:

  • true when the app is online

  • false when the app is offline

Step 3

Initialize the extension and provide it when creating a middleware or meta reducer:

import OfflineWeb from '@redux-beacon/offline-web';
// Pass the connectivity selector from Step 2 as the first parameter
const offlineStorage = offlineWeb(isConnected);
// Create or import an events map and target.
// See "getting started" pages for instructions.
const middleware = createMiddleware(eventsMap, target, { offlineStorage });
const metaReducer = createMetaReducer(eventsMap, target, { offlineStorage });

Now, whenever your app loses connection, your analytics events will now be saved offline until it regains its connection.