GSoC’ 16: Port Search Configuration module; coding week #3

Google Summer of Code (GSoC’ 16) is entering into the mid-Term evaluation stage. I have been working on the porting search configuration module for Drupal for the past three weeks.

Search configuration module helps to configure the search functionality in Drupal. This is really an important feature when it comes to a content management system like Drupal. I am almost mid-way in the port process as indicated in the timeline of Google Summer of Code.

It is really a great feeling to learn the Drupal concepts this summer. I would like to take this opportunity to share with you some key aspects I had to deal with in the past week.

Once a module is installed and later on if some changes are amended, we need not rewrite the Drupal code. Instead, Drupal gives up the option to make use of a hook, function hook_update_N which helps us to write the update needed and the database schema gets updated accordingly. Currently, since my module is just going into its first release after this port process, I need not write an update function. I just have to make this update in connection with the earlier code. The same hook works for both Drupal 7 and 8.

Another feature is the hook_node_insert, this hook is invoked to insert a new node into the database. So, here we are writing into the database a drupal record. In Drupal 7, this insertion was done by the drupal_write_record(). But,in D8, it has been replaced by the merge query and the entity API. The merge queries support the insert and update options to the database.

In connection with the nodes, another hook function is the hook_node_update. This functionality updates the node contents which has been inserted into the Drupal record (database). This takes in an argument, obviously,  the node has to be passed, for which the updating is intended.

The hook_uninstall gets invoked as the name suggests, in the uninstall process of the modules. The hook removes the variable used by the module so as to free the memory. It also modifies the existing tables if required. The D7 version of Drupal used the  variable_del for removing the variables.

For instance,

variable_del($nameOfVariable);

// Drupal 7 code

This has been replaced by the delete() of the configuration API.

i.e,

\Drupal::service('config.factory')->getEditable('search_config.settings')->delete();

search_config.settings is the default configuration file.

I will post the updates on this port process regularly. Please wait for the future posts.