All the Functions for use with Drupal's Ajax framework are situated at /includes/ajax.in

Drupal's Ajax framework is used to dynamically update parts of a page's HTML based on data from the server.

Upon a specified event, such as a button click, a callback function is triggered which performs server-side logic and may return updated markup, which is then replaced on-the-fly with no page refresh necessary.

Before you can get the LDAP module for Drupal up and functioning, you have to have certain prerequisites already installed and setup on the server.

Deprecated Calls :

• watchdog

Instead use

\Drupal::logger('devel')->notice($message); // to log notice

\Drupal::logger('devel')->error($message); // to log error

• checkPlain

Will be removed from Drupal 9 onwards so suggested not to use in Drupal 8 as well.

Rely on Twig's auto-escaping feature, or use the #plain_text key when constructing
a render array that contains plain text in order to use the renderer's auto-escaping feature.

Basics of Drupal Behaviours

1. https://benmarshall.me/drupal-behaviors/

Drupal-8 Architecture Explained Nicely

1. https://cipix.nl/understanding-drupal-8-part-1-general-structure-framework

Drupal Contributors Helpful Tool (Works on Chrome and Safari)

Obtain or update a copy of the project

1. Clone the project to obtain a copy of it that you can work with locally. You only need to do this once per project.

git clone --branch [branchname] http://git.drupal.org/project/[project_name].git

2. If you have already cloned, pull the latest changes down to ensure you're working on the latest code.

git checkout [branchname]
[branchname] might be 7.x-2.x for example. Refer : https://drupal.org/node/1054616

In order to use Coder module, you would need to Install Coder Sniffer on your machine.  

A detailed steps can be found at  https://www.drupal.org/node/1419988 for Installing Coder Sniffer.   Please follow the steps and you will have it ready to use.

A detailed information about Command Line Usage can be found at https://www.drupal.org/node/1587138

Commands For checking Coding Standards in Drupal 8

  define( 'ABSPATH', true );
  include 'inc/simplexlsx.class.php';
  require_once 'inc/excel_reader2.php';

  $file = $form_state['storage']['file'];
  $file->status = FILE_STATUS_PERMANENT;
  $filepath = drupal_realpath($form_state['storage']['file']->uri);

  ################### mapping of excel readers ###################
    $ext = pathinfo($filepath, PATHINFO_EXTENSION);
  ################################################################

  $output = array();
  //extension logic starts here
  $xlsx_rw = NULL;

To write a cron you need to implement hook_cron() in your module. Then, drupal will automatically execute these tasks during the default cron handling.

Note that, using drupal_set_message() function in a hook_cron() implementation makes no sense because there is no user to read these messages. As an alternative, you could log messages with watchdog().

In Drupal 7 you can enable cron via the Administration > Configuration > System > Cron (admin/config/system/cron)

Simplenews Change Un-subscribe URL to Shorten bitly URL

I know, most of times (or should I say always ?) you feel need of installing JAVA from your Ubuntu Machine.  But how about, I installed Java and for some reasons, I don't want it on my machine anymore ?  
Well, here are few direct steps to achieve so.

• Remove all the Java related packages (Sun, Oracle, OpenJDK, IcedTea plugins, GIJ):

dpkg-query -W -f='${binary:Package}\n' | grep -E -e '^(ia32-)?(sun|oracle)-java' -e '^openjdk-' -e '^icedtea' -e '^(default|gcj)-j(re|dk)' -e '^gcj-(.*)-j(re|dk)' -e '^java-common' | xargs sudo apt-get -y remove