Login Form with ReactJS

import React, { Component } from 'react';
import { Button, Form, FormGroup, Label, Input, Fade  } from 'reactstrap';
import _ from 'lodash';

const validationMethods =  {
    required : (field, value) => {
        if (!value.toString().trim().length) {
            return  `This ${field} field is required.`
        }
    },
    isEmail: (field,value) => {
        var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
        if (reg.test(value) === false) {
            return  `Invalid Email Address.`
        }        
    }
} 

const validateForm = (form) => {
    const loginForm = document.getElementById(form)
     return loginForm.querySelectorAll('[validations]');
}

const runValidationRules  = (element, errors) => {
    const target = element;
    const field =  target.name;
    const value = target.value
    let validations =  element.getAttribute('validations');
    validations =  validations.split(',')

    for (let validation of validations) {
        validation = validation.split(':');
        const rule = validation[0];
        const error = validationMethods[rule](field, value);
        errors[field] = errors[field] || {};
        if(error) {
            errors[field][rule] = error;
        } else {
            if(_.isEmpty(errors[field])) {
                delete errors[field];
            } else {
                delete errors[field][rule];
            }
        }
    }

    return errors;
}


export default class Login extends Component {

    constructor(props) {
        super(props);
        this.state = {
            email: '',
            password: '',
            errors: []
        }
    }



    login = (event) => {

        event.preventDefault();

        const formElements = validateForm("loginForm");
 
        formElements.forEach(element=> {
           const errors = runValidationRules(element, this.state.errors);
            this.setState({
                errors: errors
            });
        })

        const email = this.state.email;
        const password = this.state.password;
        const errors =  this.state.errors;
        console.log(email, password, errors);
    }

    handleChange = (event) => {
        const target = event.target;
        const field =  target.name;
        const value = target.value

        const errors = runValidationRules(target, this.state.errors);

        this.setState({
            errors: errors
        });

        this.setState({
            [field]:  value
        });
    }

    render() {
        return (
            <div className="container">
                <Form id="loginForm" method="post" onSubmit={this.login}>
                    <FormGroup>
                        <Label for="email">Email</Label>
                        <Input
                            type="text"
                            validations={['required','isEmail']}
                            name="email"
                            value={this.state.email}
                            onChange={this.handleChange}
                            id="email"
                            placeholder="Enter your email address."
                        />
                      <FromValidationError field={this.state.errors.email} />
                    </FormGroup>
                    <FormGroup>
                        <Label for="password">Password</Label>
                        <Input
                            type="password"
                            validations={['required']}
                            name="password"
                            value={this.state.password}
                            onChange={this.handleChange}
                            id="password"
                            placeholder="Enter your password."
                        />
                        <FromValidationError field={this.state.errors.password} />
                    </FormGroup>
                    <Button>login</Button>
                </Form>
            </div>
        );
    }
}

const FromValidationError = props => (
    <Fade in={Boolean(props.field)}  tag="p" className="error">
       { props.field ?  Object.values(props.field).shift() : '' } 
  </Fade>
);

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import React, { Component } from 'react';

import { Button, Form, FormGroup, Label, Input, Fade } from 'reactstrap';

import _ from 'lodash';

const validationMethods = {

required : (field, value) => {

if (!value.toString().trim().length) {

return `This ${field} field is required.`

}

isEmail: (field,value) => {

var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

if (reg.test(value) === false) {

return `Invalid Email Address.`

}

const validateForm = (form) => {

const loginForm = document.getElementById(form)

return loginForm.querySelectorAll('[validations]');

}

const runValidationRules = (element, errors) => {

const target = element;

const field = target.name;

const value = target.value

let validations = element.getAttribute('validations');

validations = validations.split(',')

for (let validation of validations) {

validation = validation.split(':');

const rule = validation[0];

const error = validationMethods[rule](field, value);

errors[field] = errors[field] || {};

if(error) {

errors[field][rule] = error;

} else {

if(_.isEmpty(errors[field])) {

delete errors[field];

} else {

delete errors[field][rule];

}

return errors;

}

export default class Login extends Component {

constructor(props) {

super(props);

this.state = {

email: '',

password: '',

errors: []

}

event.preventDefault();

const formElements = validateForm("loginForm");

formElements.forEach(element=> {

const errors = runValidationRules(element, this.state.errors);

this.setState({

errors: errors

});

})

const email = this.state.email;

const password = this.state.password;

const errors = this.state.errors;

console.log(email, password, errors);

}

handleChange = (event) => {

const target = event.target;

const field = target.name;

const value = target.value

const errors = runValidationRules(target, this.state.errors);

this.setState({

errors: errors

});

this.setState({

[field]: value

});

}

render() {

return (

<Label for="email">Email</Label>

<Input

type="text"

validations={['required','isEmail']}

name="email"

value={this.state.email}

onChange={this.handleChange}

id="email"

placeholder="Enter your email address."

</FormGroup>

<Label for="password">Password</Label>

<Input

type="password"

validations={['required']}

name="password"

value={this.state.password}

onChange={this.handleChange}

id="password"

placeholder="Enter your password."

</FormGroup>

<Button>login</Button>

</Form>

</div>

);

}

const FromValidationError = props => (

{ props.field ? Object.values(props.field).shift() : '' }

</Fade>

);

I hope you like this Post, Please feel free to comment below, your suggestion and problems if you face - we are here to solve your problems.

Arjun

I am Arjun from Hyderabad (India). I have been working as a software engineer from last 7+ years, and its my passion to learn new things and implement them as a practice. Aside from work, I likes gardening and spending time with pets.