Kontact NPM | npm.io

kontact

An extensible contact form in PHP and vanilla JavaScript/AJAX.

Quick start

Clone this repo into a location accessible via localhost. For example:
```
$ cd ~/Sites
$ git clone https://github.com/yuanqing/kontact
$ cd kontact/example
```
Or simply upload this repo onto a web server that can execute PHP.
Open example/index.php on a web browser, and have a go at submitting the contact form.

Usage

Our contact form is composed of the following:

• example/index.php

This is the HTML for the contact form itself.

<body>
  <form action="mail.php" method="post" class="kontact">
    <div><label for="name">Name</label><input type="text" name="name" id="name" value="<?php echo @$_GET['data']['name']; ?>" /></div>
    <div><label for="email">Email</label><input type="text" name="email" id="email" value="<?php echo @$_GET['data']['email']; ?>" /></div>
    <div><label for="message">Message</label><textarea name="message" id="message"><?php echo @$_GET['data']['message']; ?></textarea></div>
    <div><input type="submit" value="Send" /></div>
  </form>
  <script src="../js/src/kontact.min.js"></script>
  <script src="script.js"></script>
</body>

The js/src/kontact.min.js and script.js JavaScript files are to be placed just before the closing body tag.
The action attribute of the form is mail.php.

• example/script.js

This is the JavaScript that sends the user input via AJAX to mail.php.

var form = document.querySelectorAll('.kontact')[0];
kontact(form, function(err, data) {
  if (err) {
    // do stuff with `err`, eg. manipulate the DOM to show error messages
    return;
  }
});

kontact(form, cb)

Listens to the submit event on the given form, and sends the user input for validation.

form is a DOM element. User input is sent to the URL specified in its action attribute. (In our example, action is mail.php.)
Form validation results are returned via the cb(err, data) callback. The value of err may be one of:

0 — No error in user input.
array — There was an error in the user input. Each element in the array corresponds to a form field where there had been an error.
data is an array containing the user input.

• example/mail.php

This is the PHP script that processes the submitted form, and returns a response. It requires the file php/src/Kontact.php.

require_once dirname(__DIR__) . '/php/src/Kontact.php';

use yuanqing\Kontact\Kontact;

$schema = array(
  'name' => array(
    'optional' => true,
    'err' => 'Please enter your name'
  ),
  'email' => array(
    'validate' => function($input) {
      return filter_var($input, FILTER_VALIDATE_EMAIL);
    },
    'err' => 'Please enter a valid email'
  ),
  'message' => array()
);
$cb = function($err, $data) {
  if (!$err) {
    // do stuff with `$data`, eg. send mail($to, $subject, $message)
    return;
  }
};

$kontact = new Kontact($schema, $cb);

$kontact->process($_POST, 'example.php');

Kontact::__construct($schema, $cb)

Constructs a new Kontact instance.

$schema is an array, with each element corresponding to a form field. The key is the name of the form field. The value is an array containing the following:

optional — Set to true if the form field can be empty. Defaults to false.
validate — A callable for validating user input. It must return false if the user input is invalid.
err — The error message (a string) that is returned if optional is false but the field was empty, or if the validate callaback returned false for the given user input.

$cb is a callable that is passed the results of the form validation (namely, the $err messages and the user input $data). Do server-side stuff in $cb, eg. send email, or add $data to a database.