use of do_action() without any functions attached

Question

According to docs:

do_action( string $tag, $arg = '' )

Execute functions hooked on a specific action hook.

I have already written plugins. and they have many do_action() function without any functions hooked to that specific hook.

What is the use of do_action( 'wpdocs_i_am_hook'); with wpdocs_i_am_hook used nowhere else?

Answer 1

If you are seeing this in plugins (or leaving them in your own) then you are making your plugins more developer friendly.

For example, we can use do_action('stv_plugin_on_form_submit', $entry, $form, $user); inside a custom plugin that tracks form submissions. After all of your code and before the function completes, adding the do_action would enable another developer to extend the functionality of your plugin.

Here's my "extension" to your plugin via the action defined:

add_action('stv_plugin_on_form_submit', 'tom_custom_stv_plugin_on_form_submit');
function tom_custom_stv_plugin_on_form_submit($entry, $form, $user){
    //send HTTP POST to API
}

If you're using this technique, you are ensuring that your plugin (or theme) is more flexible for other to use in the future.

Further reading:

• https://developer.wordpress.org/reference/functions/do_action/
• https://wpshout.com/apply_filters-do_action/
• https://zellwk.com/blog/wordpress-actions-and-filters/