App Upgrade

The offline metadata file present on the server decides whether the offline app in the devices needs to be upgraded or not.

The offline metadata file looks like this:

{
    "latestAndroidAppUrl": "https://www.dropbox.com/s/url/for/android/apk",
    "latestChromeAppUrl": "https://www.dropbox.com/s/url/for/chrome/app",
    "compatibleVersions": [0.79, 0.80]
}

The offlineMetadata.json will be present in `/var/www/html/offlineMetadata.json'.

When the device is connected to network, it reads the metadata file and determines whether it has a update.

There are two kinds of update:

1. Forced update - this means that installed version in device is not compatible with server and it needs to be upgraded for the data to get synced to server. In this case, each time the app tries to sync data to the server, it shows a popup which has  link/button to upgrade the app.
2. Non-forced update - this means that installed version in device is still compatible with server and it need not be upgraded immediately to get data synced. In this case, sync happens smoothly even if app is not upgraded.