WordPress developers may be tempted to alter this popular website builder directly, but that method poses continuous maintenance issues. Fortunately, WordPress hooks, actions, and filters provide an easy method to add new functionality.
WordPress is the best CMS, which may not always suit all of your needs out of the box. If you want to customize it for your company, you may utilize WordPress hooks, which are open-source, rather than hacking it. It’s a successful technique for WordPress developers to use hooks, which allows them to design whatever feature they can imagine for their site.
Actions and Filters for WordPress Hooks
It is via WordPress hooks that various WordPress components communicate with one another, making them more than simply useful tools for theme developers. We consider adding styles or scripts to a page or enclosing footer material with HTML elements to be routine chores that are handled by hooked functions. Hundreds of thousands of hooks may be found in WordPress Core’s source. Additional hooks may be found in WordPress themes and plugins.
First, let’s take a look at the structure of WordPress before diving into the specifics of action and filter hooks.
WordPress Setup and Maintenance
WordPress Core: WordPress’ modular features are easy to mix and match since they all work together seamlessly. In order for WordPress to function, you’ll need to have these files. The WP Admin panel, database queries, security, and more are all provided by WordPress Core. A MySQL database is used to store the content of WordPress’s core software.
Child Theme: To fine-tune the fundamental layout and design provided by parent themes, we construct our own child themes. Modifying inherited functionality, as well as adding or removing post kinds, may be accomplished using stylesheets and scripts defined by child themes. The instructions for the child theme always take precedence over those for the parent theme.
Plugins: There are hundreds of third-party plugins available for WordPress that allow us to increase the back-end capabilities. It is possible that plugin hooks may send us emails when a post is published, or they may choose to suppress comments that include offensive language posted by users.
Custom Plugin: When a third-party plugin doesn’t suit the demands of a WordPress development company, we may write a custom PHP plugin in order to get the most out of it. A new plugin may also be written from scratch. In both scenarios, we would add hooks to expand the functionality of the system.
In WordPress, why do we need hooks if we have access to all five layers?
The Code’s Security
New features and bug fixes are constantly released to WordPress Core, parent themes, and plugins by developers in order to stay up with the rapidly changing technological landscape. The code’s security falls in the list of 7 top WordPress security to be considered. The inability to maintain WordPress components up to date might put a site at risk or even cause it to go down. If we make changes to upstream WordPress components locally, we run into trouble since updates invalidate our changes. When modifying WordPress, how can we avoid this? For example, in the child theme or a bespoke plug-in (s).
Coding in the Theme of Our Child
Creating a child theme is a way for us to tweak the appearance and feel of our installed theme in a secure environment. Any code placed here will overwrite equivalent code in the parent without the danger of being overridden by an update. When a child theme is active, it connects to a deactivated parent, inheriting and showing the parent’s attributes while staying unimpacted by the parent’s modifications. Best practices recommend activating a child theme as part of our setup to avoid the temptation to change the theme.
Creating a Custom Plug-In (s)
Each time a request is sent to the server, the plugin’s functions.php file is executed. As a result, WordPress loads all plugin hooks in order of importance and executes them one at a time. We can develop our own WordPress custom plugin to expand the capabilities of a third-party plugin.
Preparation for the Dive: Defined
We’ll stick to the following language to prevent confusion, In WordPress, a hook is a convenient place to register functions for automatic execution. Hooks in WordPress and its components allow us to link our functions to one another, or we may design our own. An action hook executes commands.
Running filters via a filter hook
Custom PHP callback functions that have been “hooked” into a WordPress hook location are known as “hooked functions.” For example, if the hook is supposed to enable external modifications, such as changing a database or sending an email, then the sort of hook to employ is dependent on whether or not the function itself may be manipulated. As a result, they are referred to as adverse consequences.
In order to prevent unwanted side effects, filters should only act on and then return a changed copy of the data it receives from its input. In contrast, the purpose of an action (or action function) is to have a negative impact on the environment. It returns nothing. Hooks may now be studied in more depth with these differences in mind.
Code Clarity and Abstraction
We meet our goals of developing just one function for each activity and avoiding code duplication when an action or filter is put into a hook. Let’s imagine we want to use the same stylesheet for our theme’s archive, single page, and custom post page templates, respectively. The wp_head hook allows us to build a single function and connect it to the wp head section rather than overriding each template in the parent and re-creating each in our child theme.
By giving a child theme or custom plugin hooks a distinct name, conflicts can be avoided in advance. A single site with multiple hooks with the same name is a recipe for unexpected code behavior. According to best standards, we should start the name of our hook with a special, brief prefix (such as the author’s, project’s, or company’s initials), followed by a name that is descriptive. For the project Tahir’s Fabulous Plugin, we might name our hooks tfp-upload-document or tfp-create-post-news using the pattern “project initials plus hook name.”
Concurrent Development and Debugging
A single hook may trigger more than just one action or filter. For example, we could write a web page that contains multiple scripts, all of which use the wp_head action hook to print HTML (e.g., a <style> or <script> section) within the <head> section on the page’s front end. Thus, by wordpress plugin development several developers can advance multiple goals in parallel on a single plugin, or divide the plugin into multiple, simpler individual plugins. If a feature does not work properly, we can directly investigate and debug its hooked function without having to search the entire project. An action can interact with an API to transmit data (e.g., a link to a post on social media), but it will not return data to the calling hook.
Let’s say we would like to automate the sharing of all new posts on our site via social media. Begin by looking through WordPress documentation for a hook that can be triggered whenever a post is published. There are no shortcuts to finding our hook: We would learn through experience or pore through the listed actions to find likely candidates. We might consider save_post a candidate, but quickly rule it out since it would trigger multiple times during a single editing session. A better choice is transition_post_status, which triggers only when a post status is changed (e.g., from draft to publish, from publish to trash).
We will go with transition_post_status but will also refine our action to run only when the status of our post transitions to publish. Further, by following the official documentation and APIs of the various social media platforms, we can integrate and publish our post’s content, along with a featured image:
A filter allows us to modify data before it is processed for display in a browser. To this end, a filter accepts variable(s), modifies the passed value(s), and returns data for further processing. WordPress checks for and executes all registered filters before preparing content for browsers. This way, we can manipulate data before sending it to the browser or database, as appropriate. One of my clients personalizes the products he sells by imprinting them with images that customers provide. This client uses the WooCommerce plugin to manage e-commerce. WooCommerce does not support this functionality out of the box. Therefore, I added two bits of code to my client’s functions.php: