CODEWITHSUNDEEP
flutter
Nithyashree B L
Nithyashree B L

Reputation: 267

How to restrict the user from entering space at the beginning in a textfield in flutter?

inputFormatters: [
                FilteringTextInputFormatter.allow(RegExp(r'^[^\s][a-zA-Z ]')),
              ],

I tried this regex expression in the TextFormField but it is not taking alphabets also. I want the text field to restrict the space at the beginning but allow in the middle. How to achieve it?

Upvotes: 0

Views: 1068

Answers (5)

rasityilmaz
rasityilmaz

Reputation: 1389

class CustomFormatter extends TextInputFormatter {
  CustomFormatter();

  @override
  TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
    if (newValue.text.isNotEmpty) {
      if (newValue.text.length > oldValue.text.length) {
        return TextEditingValue(text: newValue.text.trimLeft(), selection: TextSelection.collapsed(offset: newValue.text.trim().isNotEmpty ? newValue.selection.end : 0));
      } else {
        return newValue;
      }
    }
    return newValue;
  }
}


TextField(
     inputFormatters: [CustomFormatter()],
            ),

Upvotes: 1

TripleNine
TripleNine

Reputation: 1932

Your regex only allows one symbol in range of [a-zA-Z]. To allow multiple symbols you should try this:

RegExp(r'^[^\s][a-zA-Z ]*$')

or shorter:

RegExp(r'^\S[a-zA-Z ]*$')

Upvotes: 0

Franz
Franz

Reputation: 786

I would use the controller like MyCar said and additionaly put a logic in the onChanged() method of the text field. Then just check if the first character is space and if yes, remove it.

TextFormField(
  controller: controller,
  onChanged: (value) {
    if (value.isNotEmpty) {
      if (value[0] == " ") {
        controller.text = value.trimLeft();
      }
    }
  },
),

Upvotes: 1

mohamad kanina
mohamad kanina

Reputation: 31

just use function trimLeft() with your TextEditingController Like this

yourController.text.trimLeft()

Upvotes: 1

My Car
My Car

Reputation: 4556

You should use TextEditingController:

final TextEditingController controller = TextEditingController();

TextFormField(
  controller: controller,
),

controller.text.trimLeft()

Upvotes: 2

Related Questions