In this technical blog post, we'll delve into the world of WordPress filters with a specific focus on the add_filter
function in conjunction with array_map
. These two powerful tools allow developers to modify and manipulate data seamlessly within the WordPress environment.
Our journey begins with a filter named 'list_products_objects'
. This filter is specifically designed to handle an array of product objects, so any callback function must expect an array of objects rather than an array of IDs. This distinction is crucial for successful filter implementation.
Now, let's introduce the array_map()
function, which plays a vital role in this process. This function has the ability to apply a specific function to every element within an array and then store the results back into the original array. In this context, array_map()
takes an ID, retrieves the corresponding product, and then saves it back into the array.
Unfortunately, the filter name, 'list_products_objects'
, doesn't accurately reflect the intended functionality. It would be more appropriate to use a name that explicitly describes the purpose of the filter, such as 'filter_product_objects'
.
add_filter( 'list_products_objects', static function ( $products ) { if ( empty( $products ) || ! is_array( $products ) ) { return $products; } // Remove any empty entries. $products = array_filter( $products ); $filtered_products = array(); foreach ( $products as $product ) { if ( ! has_term( array( 'mugs', 'tshirts' ), 'product_cat', $product->get_id() ) ) { continue; } $filtered_products = $product; } return $filtered_products; } );
In this code snippet, the filter callback function accepts an array of product objects as input. It first checks if the array is empty or not an array. If either condition is met, the function simply returns the original array. Then, it filters out any empty entries using array_filter()
.
The next step is to initialize an empty array called $filtered_products
. This array will store the products that meet the filtering criteria.
The code then iterates through each product in the original array using a foreach
loop. For each product, it checks if it belongs to the 'mugs' or 'tshirts' product category using the has_term()
function. If the product meets this condition, it is added to the $filtered_products
array.
Finally, the $filtered_products
array, which contains only the products from the 'mugs' and 'tshirts' categories, is returned as the output of the filter.
By utilizing the add_filter()
function along with array_map()
, developers can effortlessly modify and manipulate data within WordPress, enhancing the functionality and user experience of their websites.