How to pass widget constructor as a parameter for another widget to build












1















Is there a way to pass one widget as a parameter to another?



My code has something similar to this with two TextWidget of type BoldWidget and ItalicWidget:



abstract class TextWidget extends StatelessWidget {
final String text;

TextWidget({
@required this.text,
});
}

class BoldWidget extends TextWidget {
@override
Widget build(BuildContext context) {
return Text(this.text, style: TextStyle(fontWeight: FontWeight.bold),);
}
}

class ItalicWidget extends TextWidget {
@override
Widget build(BuildContext context) {
return Text(this.text, style: TextStyle(fontStyle: FontStyle.italic),);
}
}


At runtime, I want to pass in either TextWidget as an argument to another widget (TextDisplay) like this:



class TextDisplay extends StatelessWidget {
final TextWidget widget;
final String string;

const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

@override
Widget build(BuildContext context) {
return widget(string);
}
}


What doesn't work in the code above is widget(string), with error message "'widget' isn't a function".



How can I pass one widget as another argument so it can constructed by another class?



My actual code can't build the TextWidget before passing it to TextDisplay as TextDisplay needs to apply some of the arguments to the TextWidget.










share|improve this question



























    1















    Is there a way to pass one widget as a parameter to another?



    My code has something similar to this with two TextWidget of type BoldWidget and ItalicWidget:



    abstract class TextWidget extends StatelessWidget {
    final String text;

    TextWidget({
    @required this.text,
    });
    }

    class BoldWidget extends TextWidget {
    @override
    Widget build(BuildContext context) {
    return Text(this.text, style: TextStyle(fontWeight: FontWeight.bold),);
    }
    }

    class ItalicWidget extends TextWidget {
    @override
    Widget build(BuildContext context) {
    return Text(this.text, style: TextStyle(fontStyle: FontStyle.italic),);
    }
    }


    At runtime, I want to pass in either TextWidget as an argument to another widget (TextDisplay) like this:



    class TextDisplay extends StatelessWidget {
    final TextWidget widget;
    final String string;

    const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

    @override
    Widget build(BuildContext context) {
    return widget(string);
    }
    }


    What doesn't work in the code above is widget(string), with error message "'widget' isn't a function".



    How can I pass one widget as another argument so it can constructed by another class?



    My actual code can't build the TextWidget before passing it to TextDisplay as TextDisplay needs to apply some of the arguments to the TextWidget.










    share|improve this question

























      1












      1








      1


      1






      Is there a way to pass one widget as a parameter to another?



      My code has something similar to this with two TextWidget of type BoldWidget and ItalicWidget:



      abstract class TextWidget extends StatelessWidget {
      final String text;

      TextWidget({
      @required this.text,
      });
      }

      class BoldWidget extends TextWidget {
      @override
      Widget build(BuildContext context) {
      return Text(this.text, style: TextStyle(fontWeight: FontWeight.bold),);
      }
      }

      class ItalicWidget extends TextWidget {
      @override
      Widget build(BuildContext context) {
      return Text(this.text, style: TextStyle(fontStyle: FontStyle.italic),);
      }
      }


      At runtime, I want to pass in either TextWidget as an argument to another widget (TextDisplay) like this:



      class TextDisplay extends StatelessWidget {
      final TextWidget widget;
      final String string;

      const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

      @override
      Widget build(BuildContext context) {
      return widget(string);
      }
      }


      What doesn't work in the code above is widget(string), with error message "'widget' isn't a function".



      How can I pass one widget as another argument so it can constructed by another class?



      My actual code can't build the TextWidget before passing it to TextDisplay as TextDisplay needs to apply some of the arguments to the TextWidget.










      share|improve this question














      Is there a way to pass one widget as a parameter to another?



      My code has something similar to this with two TextWidget of type BoldWidget and ItalicWidget:



      abstract class TextWidget extends StatelessWidget {
      final String text;

      TextWidget({
      @required this.text,
      });
      }

      class BoldWidget extends TextWidget {
      @override
      Widget build(BuildContext context) {
      return Text(this.text, style: TextStyle(fontWeight: FontWeight.bold),);
      }
      }

      class ItalicWidget extends TextWidget {
      @override
      Widget build(BuildContext context) {
      return Text(this.text, style: TextStyle(fontStyle: FontStyle.italic),);
      }
      }


      At runtime, I want to pass in either TextWidget as an argument to another widget (TextDisplay) like this:



      class TextDisplay extends StatelessWidget {
      final TextWidget widget;
      final String string;

      const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

      @override
      Widget build(BuildContext context) {
      return widget(string);
      }
      }


      What doesn't work in the code above is widget(string), with error message "'widget' isn't a function".



      How can I pass one widget as another argument so it can constructed by another class?



      My actual code can't build the TextWidget before passing it to TextDisplay as TextDisplay needs to apply some of the arguments to the TextWidget.







      dart flutter






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 15 '18 at 0:50









      S.D.S.D.

      201113




      201113
























          1 Answer
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          3














          You can use the CallBack pattern using typedef :



            typedef CustomCallBack = TextWidget Function(String value);

          class TextDisplay extends StatelessWidget {
          final CustomCallBack widget;
          final String string;

          const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

          @override
          Widget build(BuildContext context) {
          return widget(string);
          }
          }





          share|improve this answer























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            oldest

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            1 Answer
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            active

            oldest

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            active

            oldest

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            active

            oldest

            votes









            3














            You can use the CallBack pattern using typedef :



              typedef CustomCallBack = TextWidget Function(String value);

            class TextDisplay extends StatelessWidget {
            final CustomCallBack widget;
            final String string;

            const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

            @override
            Widget build(BuildContext context) {
            return widget(string);
            }
            }





            share|improve this answer




























              3














              You can use the CallBack pattern using typedef :



                typedef CustomCallBack = TextWidget Function(String value);

              class TextDisplay extends StatelessWidget {
              final CustomCallBack widget;
              final String string;

              const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

              @override
              Widget build(BuildContext context) {
              return widget(string);
              }
              }





              share|improve this answer


























                3












                3








                3







                You can use the CallBack pattern using typedef :



                  typedef CustomCallBack = TextWidget Function(String value);

                class TextDisplay extends StatelessWidget {
                final CustomCallBack widget;
                final String string;

                const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

                @override
                Widget build(BuildContext context) {
                return widget(string);
                }
                }





                share|improve this answer













                You can use the CallBack pattern using typedef :



                  typedef CustomCallBack = TextWidget Function(String value);

                class TextDisplay extends StatelessWidget {
                final CustomCallBack widget;
                final String string;

                const TextDisplay({Key key, this.widget, this.string}) : super(key: key);

                @override
                Widget build(BuildContext context) {
                return widget(string);
                }
                }






                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 15 '18 at 4:32









                diegoveloperdiegoveloper

                12.7k11831




                12.7k11831
































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