Check Internet

To check for internet connectivity before executing a Cubit method, simply add the checkInternet parameter to the mix function, with value checkInternet:

void loadData() {
  mix(
    key: this,
    checkInternet: checkInternet,
    ...

Now, if you try to call loadData when there is no internet connection, the method will not be executed. The Cubit will enter the failed state, and a ConnectionException with message “No internet connection” will be thrown. If you configured a UserExceptionDialog as explained earlier, an error dialog will be shown asking the user to connect to the internet.

Important: This only checks if the internet is on or off on the device, not if the internet provider is actually providing the service or if the server is available. So, it is possible that the check succeeds but internet requests still fail.

Abort silently when there is no internet

If you don’t want to show an error dialog or throw an exception when there’s no internet, you can use abortSilently: true. The method will simply not execute and return immediately, as if it had never been called:

void loadData() {
  mix(
    key: this,
    checkInternet: checkInternet(abortSilently: true),
    ...

This is useful for background sync operations where it’s acceptable to skip the operation when offline.

Throw without showing a dialog

If you want to throw a ConnectionException but handle it in your widget instead of showing a dialog automatically, set ifOpenDialog: false:

void loadData() {
  mix(
    key: this,
    checkInternet: checkInternet(ifOpenDialog: false),
    ...

Then handle the error in your widget:

if (context.isFailed(LoadData)) Text('No Internet connection');

Loading as soon as internet is available

If you have a Cubit that needs to keep trying to load from the internet until it succeeds, you can combine checkInternet with unlimited retry:

void loadData() {
  mix(
    key: this,
    checkInternet: checkInternet,
    retry: retry.unlimited,
    ...

When combined with retry, the internet check is performed before each retry attempt. If there’s no internet, it counts as a failed attempt and triggers the retry mechanism.

The checkInternet parameter has a maxRetryDelay option (defaults to 1 second) that controls how often connectivity is rechecked when there’s no internet. This allows for quicker detection of when internet comes back, regardless of the maxDelay setting in the retry parameter:

void loadData() {
  mix(
    key: this,
    checkInternet: checkInternet(maxRetryDelay: 500.millis),
    retry: retry.unlimited(maxDelay: 5.sec), // Max delay is 5 seconds for other errors
    ...

Summary of checkInternet options

The checkInternet parameter has these defaults:

checkInternet(
  abortSilently: false,    // If true, abort silently without exception
  ifOpenDialog: true,      // If true, show dialog (only when abortSilently is false)
  maxRetryDelay: 1.sec,    // Max delay between retries when no internet (with retry)
)