How to use image_save_pre filter in WordPress

image_save_pre filter

Filters the GD image resource to be streamed to the browser.

To use the image_save_pre filter, you first need to register it using add_filter. You can write this code into the functions.php of your activated theme or in a custom WordPress Plugin.

We at WePlugins always prefer to create a custom WordPress Plugin while using hooks so nothing breaks when you update your WordPress Theme in the future.

In the live examples below, we have defined a function modify_image_save_pre_defaults which takes 2 parameters and we registered it using add_filter. The first parameter image_save_pre is the name of the hook, the second parameter modify_image_save_pre_defaults is the name of the function which needs to be called, the third parameter is the priority of calling the hook if the same hook is used multiple times, and the last parameter is the number of arguments (if any) to be passed in the registered function.

Sometimes, you have to remove a registered hook so you can use remove_filter to remove the image_save_pre filter.

Parameters

Below are the 2 parameters required to use this hook.

• $image: (resource|GdImage) Image resource to be streamed.
• $attachment_id: (int) The attachment post ID.

Live Examples

Example 1: Basic Usage

Here’s a basic example of how you can use this hook.

    function weplugins_modify_image_save_pre_defaults($image, $attachment_id) { 
        // Update the $image variable according to your website requirements and return this variable. 
        // You can modify the $image variable conditionally too if you want.
        return $image; 
    }
    // Add the filter
    add_filter("image_save_pre", "weplugins_modify_image_save_pre_defaults", 10, 2);
    

Example 2: Removing the Hook

To remove a hook callback, use the example below.

    remove_filter("image_save_pre", "weplugins_modify_image_save_pre_defaults", 10, 2);
    

Make sure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

Example 3: Conditional Modification

This example shows how to modify the image resource based on certain conditions.

    function weplugins_modify_image_save_pre_conditional($image, $attachment_id) { 
        if ($attachment_id % 2 == 0) {
            // Perform some modifications for even attachment IDs
        } else {
            // Perform some different modifications for odd attachment IDs
        }
        return $image; 
    }
    // Add the filter
    add_filter("image_save_pre", "weplugins_modify_image_save_pre_conditional", 10, 2);
    

Contact Us

If you need customization or are having any trouble using this hook, please contact us. We’re always happy to assist you!