In comparison to other open source content management systems, WordPress provides a higher number of prebuilt themes, plug-ins, and extensions to web application developers. The pre-built plug-ins make it easier for developers to add features and functionality to the WordPress applications without writing additional code. The developers have option to choose from many paid and free plug-ins according to their needs. At the same time, they can easily enhance and extend the WordPress applications by creating and uploading a variety of custom plug-ins.

As a PHP script, a custom WordPress plug-in can be used for adding specific features or services to a WordPress website. But the developers must meet certain requirements to create plug-ins that can be integrated seamlessly into the WordPress application. For instance, they need to write the plug-in only in PHP. Likewise, they need to use specific access points and methods to add the custom plug-ins to the application effectively. That is why; it becomes essential for beginners to understand all aspects of WordPress plug-in development.

Understanding Important Aspects of WordPress Plug-in Development

Placing Plug-ins in the Right Folder
Based on their requirements, developers can create both large and small plug-ins. But they need to place all individual plug-ins in the plugins directory residing inside the wp-content. Normally, the small plug-ins require a single .php file. The single .php file can be stored directly in the plug-ins/ directory. On the other hand, the developers have to combine PHP functions with HTML, CSS and JavaScript while creating complex plug-ins. So they need to create separate sub-directory to create different resources used by a complex plug-in more efficiently. Also, they must name the sub-directory after the name of the plug-in.

Conveying Information to the Parsing Engine
While creating a custom plug-in, the programmers can start by creating a simple.php file, and naming the file after the name of the plug-in. But they need to ensure that the first line of the .php line must include all information required by the parsing engine. When the parsing engine failed to gather the required data, WordPress will not be able to process the plug-in. The developers must start the .php with a code snippet that includes the descriptor which is placed in the comments of a PHP file, and contain key information like plug-in name, URI, version, description, author, author URI and license.

Following WordPress Naming Conventions and Best Practices
The developers can structure the WordPress plug-in in a number of ways. But it is always important for them to keep in mind the naming conventions and best practices. The programmers familiar with the object oriented programming (OOP) feature of PHP prefer writing a single PHP file to avoid collision of function and variable names. On the other hand, the beginners prefer developing plug-ins with multiple functions and files. However, the developers must follow the naming conventions recommended by WordPress while declaring variables and naming functions. Also, they need to maintain the naming conventions consistently throughout the program.

Manipulating Plug-in Data with Actions and Filters
The developers can manipulate the plug-in data using two distinct concepts – filters and actions. These concepts enable programmers to make changes to the source code of the WordPress plug-in through WordPress admin panel. They can use filters to pass bits of data or text to WordPress. The programmers can even use custom functions make scan or filter content through filters. On the other hand, actions, unlike filters, can be used for manipulating specific areas in the templates and admin panel. The programmers can use actions for accomplishing a variety of tasks like updating content, publishing a post, saving a post, and tracking changes made to a post.

Making the WordPress Plug-in Secure
While developing a new WordPress plug-in, the developers need to ensure that it does not impact the safety and security of the website adversely. To boost the security of the plug-in the programmers must focus on two distinct aspects. On one hand, they need to ensure that the plug-is not facilitating distribution of malicious data. On the other hand, they need to ensure that the plug-in allows only authorized users to perform specific and predefined actions. Hence, the developers must scan the user input and take precautions to prevent SQL injection, while implementing robust authentication and authorization mechanisms.

Reducing Overall Overheads
While creating custom plug-ins, developers often forget to check its impact on the WordPress application’s performance and speed. Often plug-ins impacts the application’s performance by accessing a variety of unnecessary data. Likewise, most plug-ins leave a huge amount of unused data after being installed by the users. Hence, the developers need to check the resources consumed and left behind by the WordPress plug-in at the time of development. They can always consider executing specific hooks like register_activation_hook(), register_deactivation_hook() and register_uninstall_hook() each time the website administrator deactivates or uninstalls the custom plug-ins. These hooks will make it easier for administrators to use the custom plug-in without affecting the performance and functionality of the website adversely.

Making the Plug-in Available for Download
It is a common practice among developers to share the new WordPress plug-ins with other developers. When a developer wants to make the plug-ins available for download, he needs to create a readme.txt file additionally. The readme.txt file must be prepared in a standard format, and include key information like name of the developer and the functionality of the plug-in and it also help to understand Interesting Figures and Statistics about WordPress Usage. The developer has to keep the update the readme.txt file regularly by including details of the revisions made to the plug-in and updates. Also, he needs to create a web page that will act as the home page for the plug-in and help users to obtain information like functionality, usage, compatibility and installation process.

WordPress, like other open source CMS, is supported by a large and active community. The members of the robust community frequently launch new plug-ins according to the latest trends in web application development. A developer can always consider availing the assistance of the active members of the WordPress community to create custom plug-ins without putting extra time and effort.