Function and usage of preview_theme_ob_filter_callback() in wordpress


Answers ( 1 )


    The preview_theme_ob_filter_callback() function in WordPress is a callback function designed to manipulate preview theme links. This function is typically used in conjunction with preg_replace_callback() to ensure the proper handling and maintenance of locations when working with theme previews. Here's a detailed explanation:

    Function Signature:

    preview_theme_ob_filter_callback( array $matches ): string

    Function Description:

    • Purpose: This function is used to manipulate the links associated with the theme preview feature in WordPress. It primarily ensures that the theme preview is displayed correctly, maintaining the right location and context.
    • Use Case: The function is commonly used in scenarios where theme previews need to be dynamically adjusted, such as modifying URLs to suit the preview environment.


    • $matches:
      • Type: array
      • Required: Yes
      • Description: This parameter is an array of matches found by the preg_replace_callback() function. It typically contains the portions of the URL or other text that need to be filtered or altered for the theme preview.

    Return Value:

    • Type: string
    • Description: The function returns a string. This string is the modified version of the input matches, adjusted to ensure the correct theme preview functionality.

    Sample Usage:

    Here's an example of how preview_theme_ob_filter_callback() might be used in a WordPress theme or plugin:

    // Sample code to demonstrate the use of preview_theme_ob_filter_callback()
    // Assume we have a function that needs to modify theme preview links
    function modify_theme_preview_links($content) {
        // Use preg_replace_callback to find and modify specific links
        return preg_replace_callback(
            '/pattern_to_match_links/', // pattern to match the links needing modification
            'preview_theme_ob_filter_callback', // callback function to modify the matches
            $content // the content in which links are to be modified
    // Example content with links to be modified
    $content = "Some content with theme preview links...";
    // Modify the content
    $modified_content = modify_theme_preview_links($content);
    // Output or further process $modified_content as needed

    In this example, modify_theme_preview_links() is a custom function that uses preg_replace_callback() to modify certain links within a content string. The preview_theme_ob_filter_callback() function is passed as a callback to preg_replace_callback(), ensuring that each link match is processed and altered according to the requirements of the theme preview functionality in WordPress.

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