Flutter get context in initState method

Question

I'm not sure if the initState is the right function for this. What I'm trying to achieve is to check when the page is rendered to perform some checks and based on them opening a AlertDialog to make some settings if needed.

I've got a Page which has a state. It's initState function looks like this:

@override
void initState() {
    super.initState();
    if (!_checkConfiguration()) {
        _showConfiguration(context);
    }
}

The _showConfiguration like this:

void _showConfiguration(BuildContext context) {
    AlertDialog dialog = new AlertDialog(
        content: new Column(
            children: <Widget>[
                new Text('@todo')
            ],
        ),
        actions: <Widget>[
            new FlatButton(onPressed: (){
                Navigator.pop(context);
            }, child: new Text('OK')),
        ],
    );

    showDialog(context: context, child: dialog);
}

If there's a better way to make this checks and if needed call the modal, please point me in the proper direction, I was looking for a onState or onRender function, or a callback I could assign to the build function to be called on render but wasn't able to find one.

Answer 1

To execute code after the widget is fully built and laid out, you can use the WidgetsBinding.instance.addPostFrameCallback method with a callback function that checks if the configuration is valid and calls _showConfiguration if needed. Here's an example:

@override
void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
        if (!_checkConfiguration()) {
            _showConfiguration(context);
        }
    });
}

Make sure to pass a BuildContext to the _showConfiguration method. You can get the context from the BuildContext parameter of the build method or from a widget higher up in the widget tree that has a context, such as a Scaffold or a MaterialApp.

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