Developing WordPress plugins has become one of the most successful software businesses, due to the strong spread of the WordPress system, as almost half of the websites published on the Internet run this system, which is developing day after day to provide unlimited solutions to website owners and managers all over the world.
We talked before about developing WordPress templates and explained how to build a template from scratch, and now we are talking about developing WordPress plugins, which are considered one of the basic elements that almost any website running WordPress is devoid of in order to provide suitable options and features for its visitors.
The importance of developing WordPress plugins
A WordPress website can work using only a template without other additions, but in this case the options will be limited for the site manager, as a single template is not enough to launch a professional website that provides many elements and options.
The tasks performed by WordPress plugins vary , starting from very simple tasks such as printing texts on the site in different parts, to complex tasks such as creating a professional online store to display and sell products and receive payments, and other tasks that you get when you install WordPress plugins on your site.
You can get hundreds of ready-made WordPress plugins for free from the official WordPress plugin store , or other paid or free sources.
But learning how to develop WordPress plugins yourself opens up all the options for you, and gives you unlimited control over your site and applying any changes you want to it.
When you know how to develop WordPress plugins, you will not only be able to add features to your site, but you will be able to develop custom plugins that cancel some options from other plugins already installed on your site. This helps you cancel unused features that are available by default with WordPress plugins that have been installed. Install it on the site for required purposes.
Even if you do not want to develop WordPress plugins yourself, learning to develop WordPress plugins helps you understand how all the plugins that work on your site work, as well as how to modify and customize them as required.
Skills required to develop WordPress plugins
Developing WordPress plugins is something that requires basic programming experience, so it is not suitable for ordinary users of WordPress who do not have experience in programming languages. We do not recommend developing plugins if the site is published online, and you should always try the plugin on the offline version of WordPress to avoid any malfunctions. On site.
You must also have a good knowledge of the HTML language, which is used to build the visual composition of the site and print texts and various visual elements. Also, having experience in the CSS language will greatly benefit you in developing add-ons capable of aesthetically controlling the look and feel of the site and its various parts.
Your knowledge of HTML and CSS will not be sufficient to fully develop a WordPress plugin, but you must also have good knowledge of the PHP programming language through which the WordPress system was developed.
Stages of developing WordPress plugins
In order to develop WordPress plugins, you must first know what are the stages that plugin developers take to develop the plugin so that it works properly on the WordPress website.
When you enter the hosting control panel, then go to the wp-content folder within the WordPress installation path, then enter the plugins folder , you will find all the plugins installed on your site located within this directory, and each plugin has a folder with its name:
When you enter the folder for an add-on, such as the Akismet add-on, you will find that the folder contains two types of files:
- Folders containing additional options to add
- Program files contain functions that perform the various functions provided by the add-on.
We can summarize the stages of developing WordPress plugins in the following points:
- Create a folder inside the plugins directory located inside the wp-content directory in the WordPress installation directory on the hosting file manager.
- Create program files and folders belonging to the add-on.
- Writing code and functions that perform the required functions within the add-on.
- Activate the plugin from within the WordPress control panel.
Start creating a WordPress plugin
After we have indicated the skills required to be able to develop WordPress plugins, as well as the basic stages of developing the WordPress Snfoam plugin in this paragraph with the practical application of the previous steps.
We now begin to choose an expressive name for the add-on that we want to develop. For example, we will create an add-on that prints today’s date at the top of the site’s header.
We will name this add-on, for example (wpar_date). In this case, we will go to the plugin folder located inside the wp-content folder mentioned previously, then we will create a folder with the name of the plugin that we chose:
Of course, this folder is empty so far, and the add-on will not work until we enter it and start creating the necessary software files to run the add-on and have them appear in the list of WordPress add-ons in the control panel.
The first step is to create the first programming file for the add-on, where you can go into the add-on folder that you created and create a new file titled wp_date.php. For example, you can change the name however you want, but the file must have the php extension (it is better to name this file with the name of a folder addition itself)
After creating the file, write the opening code for the php language, which is as follows: <?php?>. After that, at least make a comment inside the code containing metadata for the plugin, at least the name of the plugin, so that it appears within the WordPress control panel (more metadata can be added, as we will see later).
<?php
/*
Plugin Name: Wpar_Date
*/
?>The previous code only contains a code comment in which the name of the plugin is written using the plugin name statement, which we have given the name wpar_date.
In this case, when you save this simple software file, then go to the WordPress control panel > Add-ons tab , you will find that the add-on has appeared with the name that we wrote inside the software file:
As you noticed, the plugin has appeared inside the WordPress plugins control panel and has become activated, but when activated, it will not perform any function, of course, because we have not yet written any codes inside the file.
Note : In the previous code, we wrote only the name of our add-on inside the program file. We can also write other details in addition to the add-on name, such as the description, developer link, version, and other details, which when you fill them out, appear on the add-on details page on WordPress.
<?php
/*
Plugin Name: Wpar_Date
Plugin URI:
description:
Version:
Author:
Author URI:
License:
*/
?>Only one file in the add-on folder must contain this metadata within a comment at the beginning of the file. If the add-on includes several php files, only one of these files must contain this comment.
Writing code that performs the required function of the add-on
Now we want the plugin to write today’s date at the top of the site when it is visited from the user interface, and therefore we must write the code that performs this function.
In order to be able to write code for the plugin and call it correctly within a WordPress site, you must know how WordPress hooks work, which is considered one of the important features that enables you to benefit from executing code at specific points to change the behavior of the WordPress system without the need to edit any basic files in the system itself.
Read more: Explanation of WordPress Hooks and their importance for theme and plugin developers
Now we will write the code that we want the add-on to execute within a software function, which we call the callback function, to write the programming commands within it, and this function will be able to be activated anywhere we want within the site files.
Therefore, we will now write a callback function whose only function is to write today’s date, which is recognized using the ready-made date function in PHP. Now take a look at the following code:
<?php
/*
Plugin Name: Wpar_Date
Plugin URI:
description:
Version:
Author:
Author URI:
License:
*/
function wpardate(){
echo "5/5/2023 :". date("D/Y/M");
}
?>In the previous code, we created a function called wpardate, and inside this function we used the echo command to print a fixed sentence, which is (today’s date is: ) and then we printed the date() function, which is a default function in the PHP language, as we mentioned, its function is to automatically recognize today’s date.
The code that we wrote is completely correct, but it will not work and will not print the date within the site. This is because we did not specify the point or place where the programming command should be executed to print today’s date, and here comes the role of linking this function to a suitable hook that will run it.
In order to run the function that we wrote inside the program file, we must use one of the default programming hooks in WordPress core, and here we will use the wp_head hook , which executes the associated code when displaying the site header. To connect the wpardate callback function to the hook, we will use a fixed function add_action so that the code written inside wpardate for the addition is executed when the hook occurs.
Notice that the program file, after adding the add_action definition that runs the previously written function, looks like this:
<?php
/*
Plugin Name: Wpar_Date
Plugin URI:
description:
Version:
Author:
Author URI:
License:
*/
function wpardate(){
echo "5/5/2024 :". date("D/Y/M");
}
add_action("wp_head","wpardate");
?>The add_action function in WordPress is to run the code that was written inside any callback function in the add-on code file. As you can see in the code above, it takes at least two values inside it.
The first value represents the hook to be used, and it differs depending on the place in which you want to execute the function. For example, we used the hook (wp_head) that specializes in running codes within the upper part of the Hedaer site, and the second value represents writing the name of the callback function that includes the codes to be run, which is the wpardate function in This is our situation.
You can have more control over the situation or place in which you want to run the function instead of the upper part of the header, as you can access the official Actions hooks reference for WordPress to learn about all the functions that help you professionally control the operating points of the functions that you write.
Activate the plugin on WordPress to try it
We certainly do not advise you to try new additions if the site is published directly on the Internet, and if you are forced to do so, you must make a backup copy to avoid losing any data or causing any damage to the site.
Now, after writing the function that prints today’s date, and connecting it to the appropriate hook wp_head through the add_action function in order to run it inside the header of the site, we have finished developing our simple add-on, and all we have to do now is try it on the site.
We can now go to the WordPress control panel and activate the plugin:
After activating the add-on, we can visit any page of our website, and we will notice that text showing today’s date appears on the screen:
In the same way, you can replace the function that prints the date or time on the screen with other functions that are more complex and more capable of implementing advanced programming ideas. This is the idea of famous add-ons, such as WooCommerce add-ons, for example, in which you find many multiple and expandable software files due to the many options that the add-on makes.
But in the end, the idea of a plugin can be summarized in that we determine the required function of the plugin, then we write code to implement this function, then we ask WordPress to run it by linking it to one of the appropriate hooks through the add_action function or something else.
Conclusion
After you have learned about the idea of developing WordPress plugins, you can start from this point towards writing programming codes that implement the tasks or options for which you want to develop a plugin, but we advise you not to do this except when you have completely good experience in using the PHP language and dealing with files. WordPress.
We also advise you to always make a backup copy of the site when making any modifications to the site’s code files, because this matter is completely sensitive and may cause a major malfunction in your site that you do not need.
