if statement inside widget in flutter

Question

How do I create a loop or if-statement inside a widget in flutter? It seems that you only can make a single line condition like: if(condition) but if you try to use brackets: if(condition){ } it gives an error. The same thing happens whith loops.

I want to be able to:

    RichText(
     text: TextSpan(
     text: 'Logg\n',
     children: <TextSpan>[

         if(condition){

             TextSpan( text: 'Text1\n',),
             TextSpan( text: 'Text2\n',),
          }else{

           TextSpan( text: 'Text3\n',),
           TextSpan( text: 'Text4\n',),
          }
      ]
    )

I think this is what you are looking for. stackoverflow.com/questions/49713189/… — Vraj Shah
– Vraj Shah, Commented Mar 18, 2022 at 14:37
Does this answer your question? How to use conditional statement within child attribute of a Flutter Widget (Center Widget) — Ruchit
– Ruchit, Commented Mar 18, 2022 at 15:00
yes i does! But what i not specified in my question is that i also want to know how to write a loop inside and i understand that should had specified that but i thought the answer would answer that question too, but now i understand i can not use brackets — cueless
– cueless, Commented Mar 18, 2022 at 15:21

Manishyadav · Accepted Answer · 2022-03-18 14:47:22Z

6

This one of the way that I found ,It only supports on Dart version 2.3.0 above.

For if/else

Column(
    children: [
        if (_selectedIndex == 0) ...[
             Text("Its one"),
    
        ] else ...[
          Text("Its two"),
        ],
    ],
 ),

for if / else if

Column(
    children: [
        if (_selectedIndex == 0) ...[
            Text('Its One');
        ] else if(_selectedIndex == 1)...[
            Text('Its One');
        ],
    ],
 ),

answered Mar 18, 2022 at 14:47

Manishyadav

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1 Comment

Manishyadav Over a year ago

I don't prefer this , but this is just a possibility if someone might like use it.

Nabin Dhakal · Accepted Answer · 2022-03-18 14:37:41Z

1

Try as follows:

RichText(
        text: TextSpan(
            text: 'Logg\n',
            children: value == true
                ? [
                    const TextSpan(text: 'Text1\n'),
                    const TextSpan(text: 'Text2\n')
                  ]
                : [
                    const TextSpan(text: 'Text3\n'),
                    const TextSpan(text: 'Text4\n')
                  ]))

answered Mar 18, 2022 at 14:37

Nabin Dhakal

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Comments

Kaleb · Accepted Answer · 2022-03-18 14:36:17Z

1

You cans use like this

if(condition)
   RichText(
     text: TextSpan(
     text: 'Logg\n',
     children: <TextSpan>[
             TextSpan( text: 'Text1\n',),
             TextSpan( text: 'Text2\n',),
          }
      ]
    )
else
  RichText(
     text: TextSpan(
     text: 'Logg\n',
     children: <TextSpan>[
             TextSpan( text: 'Text1\n',),
             TextSpan( text: 'Text2\n',),
          }
      ]
    )

answered Mar 18, 2022 at 14:36

Kaleb

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2 Comments

cueless Over a year ago

ok thanks. So its not possible to add an if statment with brackets inside a widget? To for example use a loop inside one of the textspan that prints "Text1\n" and "Text2\n 10 times each.

Kaleb Over a year ago

yes curly brackets cant be used in widget tree

PhilNue · Accepted Answer · 2022-03-18 14:47:50Z

0

instead of ? you can use like == or smth the ? is currently true

condition ?
       RichText(
         text: TextSpan(
         text: 'Logg\n',
         children: <TextSpan>[
                 TextSpan( text: 'Text1\n',),
                 TextSpan( text: 'Text2\n',),
              }
          ]
        )
    :
      RichText(
         text: TextSpan(
         text: 'Logg\n',
         children: <TextSpan>[
                 TextSpan( text: 'Text1\n',),
                 TextSpan( text: 'Text2\n',),
              }
          ]
        )

answered Mar 18, 2022 at 14:47

PhilNue

356 bronze badges

Comments

saeedmpt · Accepted Answer · 2022-12-05 22:51:02Z

 RichText(
          textAlign: TextAlign.center,
          textDirection: TextDirection.rtl,
          text: TextSpan(children: getTextSpan(entity,themeData))),

 List<InlineSpan> getTextSpan(FlightEntity entity, ThemeData themeData) {
List<InlineSpan> list = [];
if (entity.aircraft != null && entity.aircraft!.isNotEmpty) {
  list.add(TextSpan(text: "نوع هواپیما: ", style: themeData.textTheme.bodyText2!.apply(fontSizeFactor: 0.7)));
  list.add(TextSpan(
    text: (entity.aircraft.toString()) + "     ",
    style: themeData.textTheme.bodyText2,
  ));
}
if (entity.flightNumber != null && entity.flightNumber!.isNotEmpty) {
  TextSpan(text: "شماره هواپیما: ", style: themeData.textTheme.bodyText2!.apply(fontSizeFactor: 0.7));
  TextSpan(
    text: (entity.flightNumber.toString()) + "  ",
    style: themeData.textTheme.bodyText2,
  );
}
return list;

}

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