WordPress Zip Generator Class


This is day 24 of my WordPress Developer Advent Calendar.

In yesterday’s post, WordPress Admin Color Scheme Generator, I mentioned that I borrowed some ideas and code from the theme generator plugin. That plugin processes a source directory (the underscore theme files) and does text replacements in each file, and then adds them to a zip, which can then be downloaded. It works great, but it’s very specific to the underscore theme situation. I figured that the code and resulting logic could be extracted and made into a reusable PHP class, which can be used in different situations.

Why Code A Reusable Class?

Well, the only reason to do this would be if it can be reused in different projects. The Underscore theme generator plugin creates a zip. So does my Admin Color Scheme Generator, and I am soon going to be working on a generator for the WordPress Plugin Boilerplate, so it makes sense to create a class that all these projects can use and hopefully improve…

WP_Zip_Generator Class

So when I wrote the Admin Color Scheme Generator, I took a little bit of extra time on writing the WP_Zip_Generator class. It turned into quite a useful little class, and I am hoping others will adopt it and use it within their projects or plugins.

A description from the Github repo:

The WP Zip Generator automates a bunch of tasks related to creating a zip file that a user can download. The “source” directory is recursively iterated through and each file is processed. You can specify which files and directories to exclude from the final zip. When each file is processed, a regex replace is performed on the file contents using variables that you can specify.

Example Usage

I made this class a little differently to other classes I have done in the past. I pass in an array or arguments that the class will use, similar to how the WP_Query class works. Here is an example instantiation:

$zip_generator = new WP_Zip_Generator(array(
    'name'                 => 'admin-color-scheme-generator',
    'process_extensions'   => array('php', 'css', 'js', 'txt', 'md'),   
    'source_directory'     => dirname( __FILE__ ) . '/source/',
    'zip_root_directory'   => "color-scheme",
    'download_filename'    => "",
    'filename_filter'      => array($this, 'process_zip_filename'),
    'file_contents_filter' => array($this, 'process_zip_file_contents'),
    'post_process_action'  => array($this, 'process_zip'),
    'variables'            => $variables

As you can see, there are lots of things you can change including the files to exclude, the name of the zip file, where the source directory is, and there are also a bunch of hooks where you can customize it for your unique situation.

Filters And Hooks

Based on the name you pass into the class, you can hook into filters and actions like you would normally in WordPress. (using the name ‘doublerainbow’)

add_filter( 'zip_generator_process_filename-doublerainbow', 'process_my_file_name', 10, 2 );
add_filter( 'zip_generator_process_file_contents-doublerainbow', 'process_file_contents', 10, 2 );
add_action( 'zip_generator_post_process-doublerainbow', 'add_stuff_to_my_zip', 10, 2 );

Or you can pass in your functions, and the class will hook up everything for you:

$zip_generator = new WP_Zip_Generator(array(
    'name'                 => 'doublerainbow',
    'filename_filter'      => array($this, 'process_zip_filename'),
    'file_contents_filter' => array($this, 'process_zip_file_contents'),
    'post_process_action'  => array($this, 'process_zip'),
    'variables'            => $variables

The 2 filters and 1 action are:

  • filename_filter - use this filter to change the filename of a file in the zip.
  • file_contents_filter - use this filter to change the contents of a file in the zip.
  • post_process_action - this action fires after all files in the source directory have been processed, so you can add extra files to the zip or remove existing files etc.

If you generate zip files in WordPress, then give the class a spin, and contribute to make it better.