The TouchableOpacity function is triggered every time I press on the Textinput

Question

The TouchableOpacity function is triggered every time I press on the Textinput

Every time I press on a text input field, the login function is called

This is the touchable statement:

<TouchableOpacity
     style={InputFieldStyle.submitButton}
     onPress={this.login(this.state.email, this.state.password)}>
          <Text style={InputFieldStyle.submitButtonText}>Submit Me</Text>
</TouchableOpacity>

The login function definition:

login = (email, pass) => {
     alert(`Email: ${email} Password: ${pass}`);
};

I am currently working on Textinput in my expo project

Is there a way to prevent the login function from being called every time, or am I doing something wrong here?

javascript ajax react-native input

Answer 1

Answer №1

In the code snippet provided, the login() function is implemented as an arrow function and does not require binding using bind(). The issue lies with the onPress prop of the TouchableOpacity component. This prop should be assigned a function that will be executed when the button is pressed.

The current problem arises from directly invoking the login() function within the render() method and passing its return value (undefined) to the button. Consequently, the login() function gets called every time the render() method is triggered.

To rectify this issue, modify the code from:

<TouchableOpacity onPress={this.login(this.state.email, this.state.password)} {...otherProps}>

to

<TouchableOpacity onPress={() => {this.login(this.state.email, this.state.password)}} {...otherProps}>

Answer 2

In the code snippet provided, the login() function is implemented as an arrow function and does not require binding using bind(). The issue lies with the onPress prop of the TouchableOpacity component. This prop should be assigned a function that will be executed when the button is pressed.

The current problem arises from directly invoking the login() function within the render() method and passing its return value (undefined) to the button. Consequently, the login() function gets called every time the render() method is triggered.

To rectify this issue, modify the code from:

<TouchableOpacity onPress={this.login(this.state.email, this.state.password)} {...otherProps}>

to

<TouchableOpacity onPress={() => {this.login(this.state.email, this.state.password)}} {...otherProps}>

Answer 3

Answer №2

While the accepted answer may currently work, it is not considered a best practice. Embedding bindings in your render function can complicate code readability in the future.

Additionally, passing the email and password as parameters when they are already stored in the state is unnecessary and leads to data duplication which can cause confusion in more complex code scenarios.

A cleaner solution to address this issue would be:

login = () => {
  const { email, password } = this.state
  alert(`Email: ${email} Password: ${password}`);
}

//render
<TouchableOpacity onPress={this.login}>

Answer 4

While the accepted answer may currently work, it is not considered a best practice. Embedding bindings in your render function can complicate code readability in the future.

Additionally, passing the email and password as parameters when they are already stored in the state is unnecessary and leads to data duplication which can cause confusion in more complex code scenarios.

A cleaner solution to address this issue would be:

login = () => {
  const { email, password } = this.state
  alert(`Email: ${email} Password: ${password}`);
}

//render
<TouchableOpacity onPress={this.login}>

Answer 5

Answer №3

Utilize the TextInput component from 'react-native' in place of InputField and ensure that only one submission is made for both email and password by employing setState. For a demonstration, refer to this . Implementing this approach will assist in resolving your current issue.

Answer 6

Utilize the TextInput component from 'react-native' in place of InputField and ensure that only one submission is made for both email and password by employing setState. For a demonstration, refer to this . Implementing this approach will assist in resolving your current issue.

Answer 7

Answer №4

Transform it into an arrow function as shown below. . onPress={()=>this.login()} . That way, the function will only be triggered when a button is pressed.

Answer 8

Transform it into an arrow function as shown below. . onPress={()=>this.login()} . That way, the function will only be triggered when a button is pressed.

Answer 9

Answer №5

If you're encountering an issue with the code snippet

onPress={this.login(this.state.email, this.state.password)

To resolve this problem, you need to utilize the bind() method and include this keyword as the first parameter like so:

onPress={this.login.bind(this, this.state.email, this.state.password)}

For further information on the bind() method, check out this link: Read more about bind() method

However, there is no need to pass the email and password as parameters; you can directly access them from the state

Modify your method to appear as follows:

login = () => {
  const { email, password } = this.state;
  alert(`Email: ${email} Password: ${password}`);
}

Update your touchable component to look like:

<TouchableOpacity onPress={this.login}>

Answer 10

If you're encountering an issue with the code snippet

onPress={this.login(this.state.email, this.state.password)

To resolve this problem, you need to utilize the bind() method and include this keyword as the first parameter like so:

onPress={this.login.bind(this, this.state.email, this.state.password)}

For further information on the bind() method, check out this link: Read more about bind() method

However, there is no need to pass the email and password as parameters; you can directly access them from the state

Modify your method to appear as follows:

login = () => {
  const { email, password } = this.state;
  alert(`Email: ${email} Password: ${password}`);
}

Update your touchable component to look like:

<TouchableOpacity onPress={this.login}>

The TouchableOpacity function is triggered every time I press on the Textinput

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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