Undefined is not a function (evaluating 'this.validate')

[ridhofh]

I got error in _onPressButton, it refers to :
_onPressButton() {
// Call ValidationComponent validate method
this.validate({
userEmail: {email: true, minlength:6, required: true},
userPassword: {minlength:6, required: true}
}).then(Actions.index());
}

[perscrew]

Hi @ridhofh ! The validate methods doesn't return a promise. This is synchronous operation.

[ridhofh]

so, what must i do, to run validate function from ValidationComponent?

[perscrew]

Sorry for the delay, you just have to extend ValidationComponent to your custom React Component and call : this.validate() in your click handler.

The validate methods will populate some validation informations in the root of your component.

[stephenfromrobin]

I'm having this issue too. Could you provide some sample code?

[thg303]

see the documentation:

import ValidationComponent from 'react-native-form-validator';
 
export default class MyForm extends ValidationComponent {
  ...
}

[ArsooCh]

getting the same error
Undefined is not a function (evaluating 'this.validate')

[ghost]

import React, { Component } from 'react';
import { View, Text, TextInput, TouchableHighlight } from 'react-native';
import ValidationComponent from '../../validator/index';

export default class App extends ValidationComponent {

constructor(props) {
super(props);
// this.state = {name : "My name", email: "tibtib@gmail.com", number:"56", date: "2017-03-01"};
this.state = { name: "", email: "", number: "", date: "" };
}

_onPressButton = () => {
this._validateForm();
};
onChangeTextName = (text) => {
this.setState({ name: text });
this.validate({
name: { minlength: 3, maxlength: 7, required: true }
});

}
onChangeTextEmail = (text) => {
this.setState({ email: text });
this.validate({
email: { email: true }
});

}
onChangeTextDigit = (text) => {
this.setState({ number: text });
this.validate({
number: { numbers: true }
});

}
onChangeTextDate = (text) => {
this.setState({ date: text });
this.validate({
date: { date: 'YYYY-MM-DD' }
});

}

_validateForm() {
this.validate({
name: { minlength: 3, maxlength: 7, required: true },
email: { email: true },
number: { numbers: true },
date: { date: 'YYYY-MM-DD' }
});
}

render() {

return (
  <View style={{ paddingVertical: 30 }}>
    <Text>Name</Text>
    <TextInput ref="name" onChangeText={(name) => this.onChangeTextName(name)} value={this.state.name} />
    <Text>{(this.isFieldInError('name') && this.getErrorsInField('name'))?this.getErrorsInField('name'):''}</Text>

    <Text>Email</Text>
    <TextInput ref="email" onChangeText={(email) => this.onChangeTextEmail(email)} value={this.state.email} />
    <Text>{(this.isFieldInError('email') && this.getErrorsInField('email'))?this.getErrorsInField('email'):''}</Text>
    <Text>Number</Text>
    <TextInput ref="number" onChangeText={(number) => this.onChangeTextDigit(number)} value={this.state.number} />
    <Text>{(this.isFieldInError('number') && this.getErrorsInField('number'))?this.getErrorsInField('number'):''}</Text>
    <Text>DoB</Text>
    <TextInput ref="date" onChangeText={(date) => this.onChangeTextDate(date)} value={this.state.date} />
    <Text>{(this.isFieldInError('date') && this.getErrorsInField('date'))?this.getErrorsInField('date'):''}</Text>
   
    <TouchableHighlight onPress={this._onPressButton}>
      <Text>Submit</Text>
    </TouchableHighlight>

    
  </View>
);

}

}

[ghost]

Use this
_onPressButton = () => {
this.validate({
name: { minlength: 3, maxlength: 7, required: true },
email: { email: true },
number: { numbers: true },
date: { date: 'YYYY-MM-DD' }
});
}

Instead of
_onPressButton(){
this.validate({
name: { minlength: 3, maxlength: 7, required: true },
email: { email: true },
number: { numbers: true },
date: { date: 'YYYY-MM-DD' }
});
}

[DheereshSinghKarki]

after using arrow function too it gives same error

[callyrajiv]

@DheereshSinghKarki

You have to use 'bind' :

<TouchableHighlight onPress={this._onPressButton.bind(this)}> <Text>Submit</Text> </TouchableHighlight>

[naveenjothi]

thank you@DheereshSinghKarki its working for me