Drupal user login form customization

Customizing the user login page is very simple, and uses the following concepts:

Use preprocess to set variables
register you template file in hook_theme
create templates and render your variables

Step 1:
/**
 * Implements hook_theme().
 */
function hook_theme() {
  $items = array();
  $items['user_login'] = array(
      'render element' => 'form',
      'path' => PATH . '/templates',
      'template' => 'user-login',
      'preprocess functions' => array(
          'hook_preprocess_user_login'
      ),
  );
  return $items;
}

Step 2:
function hook_preprocess_user_login(&$variables) { 
  $variables['render_text'] = 'You can add extra text and message';
}

Step 3:
Create you template file in  your template folder
user-login.tpl.php

<div class="login-wrapper">

      <h2><?php print t('SIGN IN'); ?></h2>

      <?php
      // split the username and password from the submit button so we can put in links above
      print drupal_render($form['name']);
      print drupal_render($form['pass']);
      ?>

      <div class="login-links">
        <?php print l(t('FORGOT YOUR PASSWORD?'), 'user/password', array('attributes' => array('class' => 'login-link'))); ?>
      </div>

      <?php
      print drupal_render($form['form_build_id']);
      print drupal_render($form['form_id']);
      print drupal_render($form['actions']);
      ?>

    </div><!--//login-wrapper-->


Step 4:
Clear drupal cache

Add custom file extension in PHP application

We can add custom file extension in Apache PHP application. We can add our custom file extension instead of .php

For example, index.xyz instead of index.php

Open httpd.conf located in apache/conf folder
Find " <IfModule mime_module> "
Add " AddType application/x-httpd-php .xyz "
Restart your apache server

Status messages not removing with Commerce Ajax Cart

Use ajax_command_remove() command to remove the existing error messages while submit ajax add to cart button

$commands[] = ajax_command_remove('div.messages');
$commands[] = ajax_command_after('#main-content', theme('status_messages'));

Create an commerce order programmatically

The following steps to describe about to create an commerce order programmatically in Drupal

global $user;
$product_id = 100;
$quantity = 1;

$order = commerce_order_new($user->uid, 'cart');
commerce_order_save($order);
$line_item = commerce_product_line_item_new($product, $quantity, $order->order_id);
commerce_line_item_save($line_item);
$order_wrapper = entity_metadata_wrapper('commerce_order', $order);
$order_wrapper->commerce_line_items[] = $line_item;
commerce_order_save($order);

Implement Jquery infinite scroll plugin

Plugin Source: https://github.com/paulirish/infinite-scroll/

Automatic Scroll:
$('selector').infinitescroll(options);

 Manual Scroll:
$('#scroll-container').infinitescroll(options);
$('#scroll-container').infinitescroll('unbind');

$('.view_more').click(function() {
    $('#scroll-container').infinitescroll('retrieve');
    return false;
});

Note:
You may have to add the manual trigger behavior if you are working with masonry or isotope in order to make it work. Just include manual-trigger.js after infinitescroll and pass the behavior by passing behavior: 'twitter' when calling the plugin.