@MarkoJS Form Handler

Form Component Handler Library for MarkoJS. This library simplify how to handle the flow within a MarkoJS form component by handling all input fields events, auto-fill, auto-saving, auto-completition, validation and the form submission by binding to the this of the component. Enough talking, let get to the facts.

Installation

Install using npm

$ npm install markojs-form

Install using yarn

$ yarn add markojs-form

Usage

Create new instance of the FormHandler Object Class.

const FormHandler = require('markojs-form');

// or 

import FormHandler from 'markojs-form';

static const options = {
    key: 'form-id',
    autosave: true,
    crosscheck: true
}

static const fhandler = new FormHandler( options );

// or inside a class method

class {
    onCreate(){
        // ...
        this.fhandler = new FormHandler( options )
    }
}

Important: Avoid using form-handler instance globally.

Options

All options are optional

• key: String Same as the component tag key of the form being handled: Eg. <form key="form-id">...</form>
• autosave: Boolean Define whether to auto-save input values when the user is filling the form. Very useful especially in SPA case when the user manually or accidentally refresh the page, the inputs will stay filled with the saved values. Default false
• crosscheck: Boolean When submit form event is detected by FormHandler, it run a final validation cross-check through all inputs that require validation in the form before submitting it. Default: false

Methods

bind(this, [formObject])

Bind the form handler to the component. formObject is a object passed to the handler as the initial form fields & values: It's optional

class {
    onCreate(){
        this.state = {
            // ...
        }

        fhandler.bind(this)
    }
}

When this is done, the handler add form & formError fields to the component state: Eg. this.state.form. Those contain respectively the form data and the error status of the form validation.

Also, couple of methods are automatically bind to the component's class, to listen and handle events that occured when interacting with the form.

• __onInput Method handler for input event
• __onChange Method handler for input change event
• __onSelect Method handler for select input change event
• __onChecked Method handler for checkbox and radio input events

All these methods assigned approprietly to the various form tags, empowers the FormHandler to collect and update the data and errors state of the form component.

Example

When filling the input form below, FormHandler automatically update this.state.form.name at every input & change events, allowing the component state to be updated.

<input type="text"
        name="name"
        value=state.form.name
        on-input("__onInput")
        on-change("__onChange")>

Note: You can still assign your own method listener to handle inputs yourself. All is up to you.

unbind(this)

Unbind the form handler to the component.

set(name, value)

Manually set a value to a form input.

class {
    // ...
    onMount(){
        fhandler.set('fullname', 'John Dupont')
    }
}

fill(values)

Beside Set() method which can only set one field at a time, fill() method get an object of multiple fields & values to add manually to the form.

class {
    // ...
    onInput(){
        fhandler.fill({ status: 'healty', age: 79, gender: 'female' })
    }
}

error(name, [status])

Manually define the status of error of a given input. status can be a simple boolean: true meaning there's an error and false to cancel error. status can also be a string text message describing the error: Very usefull to display dynamic error messages to the user.

class {
    // ...
    onSubmit(){
        fhandler.error('age', 'This field is required')
    }
    onDestry(){
        // Cancel the error
        fhandler.error('age', false)
    }
}

<div>
    <input type="number"
            name="age"
            value=state.form.age
            on-change("__onChange")>
    <!-- Dislay error message -->
    <if( state.formError.age )>
        <p>${state.formError.age || 'Your custom error'}</p>
    </if>
</div>

reset()

Set the form back to its initial state. This method is automatilly call when the form get submited. It's also recommanded to call it when the form component onDestroy event occurs: Proper clean up

class {
    onCreate(){
        const initialForm = { username: 'gremdol', email: '[email protected]' }

        fhandler.bind(this, initialForm)
    }
    onDestroy(){
        // Reset the form.
        fhandler.reset()
    }
}

alert(message, status)

Display general alert of the form component

class {
    onSubmit(){
        fhandler.alert('Unexpected Error Occured! Try again', 'warning')
    }
}

<FormAlert alert=state.alert/>

Form Validation

FormHandler has couple of in-build validation rules that you can use.

• required: Specify that the input field is required
• url: Check whether the input value is a valid URL
• domain: Check whether the input value is a valid Domain/Hostname
• email: Check whether the input value is a valid email address
• phone: Check whether the input value is a valid phone number
• fullname: Check whether the input value is a valid user fullname
• password: check and return password by strengh
• number: Input value must be a valid number
• boolean: Input value must be True or False
• array: Check whether the input value is an Array: Usually set manually
• object: Check whether the input value is an Object: Usually set manually
• lowercase: Input value must be only a lowercase string
• uppercase: Input value must be onlye an uppercase string
• length: Specify the required length of the input value
• minLength: Specify the minimun length of the input value
• maxLength: Specify the maximum length of the input value

define(rule)

Define your own custom validation rules or overwrite in-build rules. There are 2 ways to define a validation rules: statically using static or $ or inside the component's class methods or right into the template:

Examples

class {
    onCreate(){
        fhandler.define([{ name: 'custom1', regexp: '/\.+/' }, { name: 'custom2', regexp: '/\w+/' }])
    }
}

<div>
    <!-- Use inbuild rules -->
    <input type="email"
            name="email"
            value=state.form.email
            validate="email"
            on-change("__onChange")>
            
    <!-- Use an already defined custom rules -->
    <input type="text"
            name="name"
            value=state.form.name
            validate="custom1"
            on-change("__onChange")>
            
    <!-- Define and assign custom rules right way -->
    <input type="text"
            name="orderId"
            value=state.form.orderId
            validate=fhandler.define([{ name: 'orderId', regexp: '/PT-(\b+{4,})-00/' }])
            on-change("__onChange")>
</div>

validate(rule, value)

Manually validate a form field.

class {
    // ... 

    onCustomHandler( value ){
        const isValid = fhandler.validate( 'email', value )

        // ...
    }
}

Events

FormHandler instanciate EventEmitter Object. Here a couple of events triggered by the form handler:

• bind: When FormHandler get bind to the component
• unbind: When FormHandler get unbind to the component
• input: New form input
• error: When an error occured
• fill: When fill() method get called
• autosave: When new auto-save record occured
• reset: When form get reset

on(event, fn)

Register an event listener

off(event, fn)

Remove an event listener

removeListeners()

Remove all event listeners

Voilà!

Feedback & Contribution

You know the say: No one is whole alone! So, feedbacks and the smallest contributions you can think of are all welcome. Kindly report any encounted Issues here and I'll be glad to work on it right away. Thank you.

License

This software is free to use under the MIT license. See the LICENSE file for license text and copyright information.