Add Widget based on Condition

Question

I want to add a MaterialButton in a widget's build method only if some condition is true. For instance:

if (..) {
    MaterialButton(..)
}

How do I achieve this in Flutter?

Answer 1

It is very simple using conditional operators:

build(context) => condition ? MaterialButton(...) : Container();

In this case, condition is a boolean expression (returning bool, same thing you would put into an if-statement) and the empty Container will render as empty space and will not take up any space.

Answer 2

Yes actually I see at least two ways of doing it.

The first one is :

Container(
  child: your_test_here ? MaterialButton() : Container(height:0), //or any other widget but not null
)

The other way of doing it is by creating a function:

Widget your_test_widget(){
  if (your_test_here){
    return MaterialButton();
  }
  else{
    return Container(height:0); //or any other widget but not null
  }
}

Call it in your tree :

Container(
  child:your_test_widget(),
)

Hope it helps !!