PHP4WP4 – Working in WordPress

The function file

Editing function.php file inside the active theme folder on wordpress is the easiest way to make changes on the site.

Downside of using functions.php

• Your changes could get overwritten on update.
• Copying the theme and modifying it is easiest, but comes with security risks. As it won’t update.

The solution is using the child theme.

Course on Linkedin Learning: WordPress: Building Child Themes.

Copying Hello Dolly

Follow the video.

WP_Query

• Class
  • A code definition or template for creating objects.
• Objects
  • A group of variables and functions marked by a single identifier

Simple personal class

Class Person { ... }

$joe = new Person( 'Joe Casabona', '34' );
$phil = new Person( 'Phil Casabona', '33');
$joe->print_name();
$joe->pring_age();

Person class replace arrays.

WP_Query use to get information from the database.

$the_query = new WP_Query( $args );

$args above is an array.

Hooks: Actions and filters

• Hooks
  • Allow us to insert our own code with WordPress without modifying “core”
  • Types of hooks
    • Actions
      • Changes how WordPress does something.
      • Imagine adding air conditioning to your house.
    • Filters
      • Modifies the information WordPress retrieves
      • Imagine painnnnnting your house.

To add action we have to use the add_action function. The example below will rung wporg_callback() when the init hook is executed.

function wporg_callback() {
  //do something
}
add_action('init', 'wporg_callback');

Actions says, whenever WordPress does this specific thing, run my function.

To add filters, use add_filter function.

function wporg_filter_title($title) {
  return 'The' . $title. 'was filtered';
}
add_filter('the_title', 'wporg_filter_title');

Filter is some piece of content that you want to change.

Filter says, take this infromation you have and change it in some way.

Let’s add a filter, to add a text, Captain’s log before the title of the blog.

function cap_log( $title ){
  return 'Captain\'s Log: ' . $title;
}

add_filter( 'the_title', 'cap_log');

Add the above code into functions.php

Conclusion of the course and Next step.