if is gutenberg page php wp

<?php
if ( function_exists( 'register_block_type' ) ) {
    function my_gutenberg_custom_block() {
        wp_register_script(
            'my-gutenberg-block',
            plugins_url( 'my-block.js', __FILE__ ),
            array( 'wp-blocks', 'wp-editor', 'wp-components' )
        );

        register_block_type( 'my-plugin/my-custom-block', array(
            'editor_script' => 'my-gutenberg-block',
        ) );
    }
    add_action( 'init', 'my_gutenberg_custom_block' );
}

Explanation: This code checks if the Gutenberg editor is available in the WordPress environment by verifying the existence of the register_block_type function. If it's present, it defines a custom block for the Gutenberg editor.

1. if ( function_exists( 'register_block_type' ) ) { ... }: This conditional statement checks if the register_block_type function exists in the current WordPress environment.

2. function my_gutenberg_custom_block() { ... }: Defines a function called my_gutenberg_custom_block() that registers a custom block.

3. wp_register_script( ... ): Registers a JavaScript file (my-block.js) as a script for the custom block. This file contains the necessary functionalities for the custom Gutenberg block.

4. plugins_url( 'my-block.js', __FILE__ ): Retrieves the URL for the JavaScript file my-block.js within the current plugin or theme directory.

5. array( 'wp-blocks', 'wp-editor', 'wp-components' ): Denotes the dependencies for the script. In this case, it requires the wp-blocks, wp-editor, and wp-components scripts to be loaded before.

6. register_block_type( 'my-plugin/my-custom-block', ... ): Registers a new custom block type with the identifier 'my-plugin/my-custom-block'.

7. array( 'editor_script' => 'my-gutenberg-block' ): Associates the previously registered script (my-gutenberg-block) with the custom block type to enable its functionality within the Gutenberg editor.

8. add_action( 'init', 'my_gutenberg_custom_block' );: Hooks the my_gutenberg_custom_block() function to the WordPress init action, ensuring that the custom block is initialized during the WordPress loading process when the init action is triggered.