如何根据数据挂钩显示内容？

Question

I do not understand why my code does not display the entry I want in my form. I want to display an invalid entry with a danger message when my user enters a phone number already in use.

I check the user input and check the Boolean display cases.

This is my booleans when I enter a phone number already used:

phoneAlreadyUsed: true
phoneCharged: false
phoneTouched: true
phoneValid: true

My code has detected that it phone number is already in use, so the boolean "phoneAlreadyUsed" is true.

This the code of my content:

    <FormGroup className="form-group">
      <Label>Phone *</Label>
      {userVerification.phoneTouched === false && userVerification.phoneAlreadyUsed === false && (
        <Input
          type="text"
          name="phone"
          className="form-control"
          value={user ? user.phone : ''}
          placeholder={'Enter your phone number'}
          onChange={handleChange}
        />
      )}
      {userVerification.phoneValid === true && userVerification.phoneAlreadyUsed === false && (
        <Input
          type="text"
          name="phone"
          className="form-control is-valid"
          value={user ? user.phone : ''}
          placeholder={'Enter your phone number'}
          onChange={handleChange}
        />
      )}
      {((userVerification.phoneValid === false && userVerification.phoneTouched === true) ||
        userVerification.phoneAlreadyUsed === true) && (
        <Input
          type="text"
          name="phone"
          className="form-control is-invalid"
          value={user ? user.phone : ''}
          placeholder={'Enter your phone number'}
          onChange={handleChange}
        />
      )}
      {userVerification.phoneAlreadyUsed === true && (
        <div class="invalid-feedback">Sorry, this phone number's taken. Try another?</div>
      )}
    </FormGroup>

My code display the second input (valid) without the message in "invalid-feedback". I don't understand why... Could you help me please?

Answer 1

You are unnecessarily duplicating a lot of code. All that is different in your cases is the className prop of the Input component. You can easily construct it:

//in render

const {phoneTouched, phoneValid, phoneAlreadyUsed} = userVerification;
let className = 'form-control';

if (phoneTouched) {
    const valid = phoneValid && !phoneAlreadyUsed;
    className += valid ? 'is-valid' : 'is-invalid';
}

return (
    <FormGroup className="form-group">
        <Label>Phone *</Label>
        <Input
          type="text"
          name="phone"
          className={className}
          value={user ? user.phone : ''}
          placeholder={'Enter your phone number'}
          onChange={handleChange}
        />
        {phoneAlreadyUsed && (
            <div class="invalid-feedback">
                Sorry, this phone number's taken. Try another?
            </div>
        )}
    </FormGroup>
);