React-forms-handler NPM

Getting Started with React forms handler

This library provides form object that can be used by React's hooks and class components

Lightweight library.
Zero dependencies.
Inspired from angular reactive form.

npm i react-forms-handler

React form handler's form was designed to work with both forms of react's components, it can be Initialized by 2 ways:

For class component use class form.
```
new Form({login: ''})
```

For function component use hooks.

import {useForm} from 'react-forms-handler';

let loginForm = useForm({login: ''});

react-forms-handler has three entities that can be initialized separately

import {
    Form
    Field,
    Fields,
} from 'react-forms-handler';

// be aware! validation package should be installed . 
// it isn't one of current package dependencies.
import validator from 'validator';

let field = new Field('', validator.isEmail);

let fields = new Fields('value_1', 'value_2');

let form = new Form({
    'email': ['',validator.isEmail],
    'password': ['', validator.isStrongPassword]
})

Each field has field.valid property

 const form = new Form({username: ''})
 
 <button  type="submit"  disabled={!form.fields.username.valid}>Submit</button>

Hooks usage

    import {useForm} from 'react-forms-handler'
    import validator from 'validator';
    import React, { useState, useEffect } from 'react';

    function LoginComponent() {

        /*
        *  We can destruct from . 
        *  In addition to form.valid and form.value you can get all the field by their name
        *  Be aware! validator isn't part of our package . you can use your favorite
        *  validation package 
        */

        const {valid, value, username, password} = useForm({
                username: ['', validator.isEmail],
                password: ['', validator.isStrongPassword]
            });
        
        return (
            
            /*
            *  field.inputProps contain onChange function and defaultValue props that 
            *  bound to the form . onBlur also bound to detect filed.touched  
            */
            
            <form >
                <label htmlFor="email" >Email</label>
                <input type="text"  id="email" {...username.inputProps} />
                {!username.valid && <div id="email-error">
                    Should be valid email!
                </div>}
                <label htmlFor="inputPassword" >Password</label>
                <input type="password" id="password" {...password.inputProps}/>
                {!password.valid && <div id="password-error" >
                    Length should be 8, password should contain at least Letters, Capital, symbol and number!
                </div>}
                <button  type="submit"  disabled={!valid}>Submit</button>
            </form>
        
        )
    }

    export default LoginComponent;

useField

Sometimes you have just one field . in such cases you don't need to use entire form Object.

import {useField} from 'react-forms-handler'
import validator from 'validator';

function NameComponent () {
    let email = useField(['', validator.isEmail])  
    return (
        <div>
            <input {...email.inputProps} />
            {email && email.valid && email.touched && <p>
                {email.value}
            </p>}
        </div>
    ) 
}

export default NameComponent;

Class usage

    import {Form} from 'react-forms-handler'
    import validator from 'validator';
    import React from 'react';

    Class LoginComponent extends React.Component {{

        constructor(){
            this.form = new Form({
                username: ['', validator.isEmail],
                password: ['', validator.isStrongPassword]
            });

            this.state = {
                formValid = this.form.valid
            }
        }

        componentDidMount() {
            this.form.stateChange.subscribe(()=>{
                this.setState({
                    formValid = this.form.valid
                })
            })
        }



        
        render() {

            return (
                <form >
                    <label htmlFor="email" >Email</label>
                    <input type="text"  id="email" {...this.form.fields.username.inputProps} />
                    {!this.form.fields.username.valid && <div id="email-error">
                        Should be valid email!
                    </div>}
                    <label htmlFor="inputPassword" >Password</label>
                    <input type="password" id="password" {...this.form.fields.password.inputProps}/>
                    {!this.form.fields.password.valid && <div id="password-error" >
                        Length should be 8, password should contain at least Letters, Capital, symbol and number!
                    </div>}
                    <button  type="submit"  disabled={!this.state.formValid}>Submit</button>
                </form>
            
            )
        }
    }
        

    export default LoginComponent;

clearAllFields

you can call clearAllFields in this way this function will clear all form's fields value to empty string

form.clearAllFields()

stateChange

you can subscribe to changes in the values of single Field Array of Fields or to Entire form

form.stateChange.subscribe((currentValue, prevValue) => {
    //do something with form value
})

fields.stateChange.subscribe((currentValue, prevValue) => {
    //do something with array of values
})

field.stateChange.subscribe((currentValue, prevValue) => {
    //do with single value
})

NOTE: Inside Function component you should wrap the subscriber by useEffect!