Understanding TextField in Flutter: Uses, Validations, and Functions

A TextField is a basic user input widget in Flutter that allows users to enter and edit text. It is widely used in various applications for accepting inputs from the users. In this blog, we will take a detailed look at the TextField in Flutter, its uses, validations, and functions.

Uses of TextField:

·         Accepting User Input: The primary use of the TextField is to accept user inputs. It can be used to receive text inputs from the user, such as names, addresses, phone numbers, and more.

·         Data Entry Forms: TextFields can also be used in data entry forms, where users are required to enter multiple pieces of information.

·         Search Bars: TextFields can be used in search bars, where users can enter keywords to search for specific information.

Validations:

1.        Required Field Validation: To validate whether the TextField is filled or not, we can use the validator property of the TextField widget. If the text entered by the user is empty, it will return an error message. Here is an example:

TextFormField(

  validator: (value) {

    if (value.isEmpty) {

      return 'This field is required';

    }

    return null;

  },

)

2.      Maximum Length Validation: To validate the maximum length of the text entered by the user, we can use the maxLength property of the TextField widget. If the text entered by the user is greater than the maximum length, it will return an error message. Here is an example:

TextFormField(

  maxLength: 10,

  validator: (value) {

    if (value.length > 10) {

      return 'Text length should be less than 10';

    }

    return null;

  },

)

3.      Functions:

1.        onChanged: This function is triggered every time the text in the TextField is changed. It returns the new text value as a parameter. Here is an example:

TextField(

  onChanged: (value) {

    print(value);

  },

)

2.      onSubmitted: This function is triggered when the user submits the text in the TextField by tapping the submit button or by pressing the enter key. It returns the text value as a parameter. Here is an example:

TextField(

  onSubmitted: (value) {

    print(value);

  },

)

3.      obscureText: This function is used to obscure the text entered in the TextField. It is often used for password fields to hide the password characters. By default, the value of obscureText is set to false. Here is an example:

TextField(

  obscureText: true,

)

In conclusion, the TextField in Flutter is a useful and versatile widget that is used for accepting user inputs. By using validations and functions, we can make sure that the inputs entered by the user are correct and secure. With the help of code examples, we have shown how to use the validations and functions of the TextField widget in Flutter.