Call Shortcode inside another Shortcodes callback

Question

I'm using a plugin that shows content only to specific user roles. This content is surrounded by a shortcode tag to make it invisible to other other user roles. Now I'd like to call other shortcodes inside that restricted content.

I understand that I need to set the plugins shortcodes up so that they use do_shortcode(), but there are so many files that I'm not sure exactly where to do this. All of the places I've tried have not made any change. Any tips on what to look for?

Here's the code block I found. I think this is what I need to edit. What do you think? Change this:

return stripslashes($message);

Change to:

return stripslashes(do_shortcode($message));

// Show the level based protected shortcode message
    function do_levelprotected_shortcode($atts, $content = null, $code = "") {

        global $M_options;

        // Set up the level shortcodes here
        $shortcodes = apply_filters('membership_level_shortcodes', array() );
        $notshortcodes = apply_filters('membership_not_level_shortcodes', array() );

        $code = strtolower( $code );

        if( substr( $code, 0, 4 ) !== "not-" ) {
            if(!empty($shortcodes)) {
                // search positive shortcodes first
                $id = array_search( $code, $shortcodes );
                if($id !== false) {
                    // we have found a level so we need to check if it has a custom protected message, otherwise we'll just output the default main on
                    $level = new M_Level( $id );
                    $message = $level->get_meta( 'level_protectedcontent' );
                    if(!empty($message)) {
                        return stripslashes($message);
                    }
                }
            }
        } else {
            if(!empty($notshortcodes)) {
                // search positive shortcodes first
                $id = array_search( $code, $notshortcodes );
                if($id !== false) {
                    // we have found a level so we need to check if it has a custom protected message, otherwise we'll just output the default main on
                    $level = new M_Level( $id );
                    $message = $level->get_meta( 'level_protectedcontent' );
                    if(!empty($message)) {
                        return stripslashes($message);
                    }
                }
            }
        }

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EDITORS NOTE: I removed all the links to the (closed source) plugins as they're as relevant for the actual question as the plugins source code is accessible: zero.

Answer 1

tl;dr

1. Find where the shortcode is registered.
2. Find the shortcode output function.
3. Pray for a filter.
4. Report as a bug.

Remember: All of the functions below are made up. The point of the first two steps is finding the right values to plug into the snippets.

---

Find where the shortcode is registered

Use a program like Notepad++ or Sublime Text 2 (my personal favorite) that can search multiple files at once. Then search for some variation of the following, where "member" is the shortcode you're using:

• add_shortcode( 'member'
• add_shortcode('member'
• add_shortcode( "member"
• add_shortcode("member"

Find the shortcode output function

One of those will likely lead you to a line of code that looks like this:

add_shortcode( 'member', 'member_shortcode' );

Then you'll need to find the "member_shortcode" function. Look near the add_shortcode function to see if you see it. If not, do a search for:

function member_shorcode(

Pray for a filter

And then this is the moment of truth. You're praying this whole time that the shortcode provides a filter for the shortcode output. That would let you do something like this:

function recursive_member_shortcode( $content ) {
    return do_shortcode( $content );
}
add_filter( 'member_shortcode_filter', 'recursive_member_shortcode', 9999 );

If there is no filter, your only option is to hack the plugin file itself which is bad news.

Report as a bug

To be honest, having said all of the above, this seems to be a bug to me, and I'd report it to WPMU. But given my experience with their support and code-quality, I wouldn't get my hopes up.

Answer 2

Whatever you need to do with shortcodes: You can always filter them.

Core uses the following filter.

apply_filters( "shortcode_atts_{$shortcode}", $out, $pairs, $atts );

So, as long as the third argument is used when calling shortcode_atts(), it's easy as your filter callback can simply hook into

"shortcode_atts_{$third_Argument}"

If that's not the case (and as it's optional, most developers forget about it), you'll have to search for unique (as much as this is possible) identifiers in the callback arguments.

Then you can filter the output. Attaching other shortcodes and every other funk is no problem from there.

Note: I'm not sure how much this answer is on topic with the question.