Shortcode API: How to get name that matched shortcode RegEx?

Question

I am looking for a way to reproduce what is described in the documentation: An overloaded shortcode callback.

According to the docs, the $atts array will contain the string that matched the shortcode RegEx. The position inside $atts depends on if the callback name matches the shortcode or not. The following example is taken from the docs:

add_shortcode('foo','foo'); // two shortcodes referencing the same callback
add_shortcode('bar','foo');
  produces this behavior:
[foo a='b'] ==> callback to: foo(array('a'=>'b'),NULL,"foo");
[bar a='c'] ==> callback to: foo(array(0 => 'bar', 'a'=>'c'),NULL,"");

So I registered my shortcodes like this:

add_shortcode('foo', 'foo');
add_shortcode('bar', 'foo');
function foo($attributes, $content = null) {
    echo '<pre>';
    var_dump($attributes);
    echo '</pre>';
}

Unfortunately, $attributes is always empty, it does not contain the name of the shortcode (WP 4.0).

Is this an error in the documentation or am I going wrong somewhere?

Answer 1

I think you just forgot to run the shortcodes [foo a='b'] and [bar a='c'] through the do_shortcode filter:

do_shortcode( '[foo a='b'] [bar a='c']' )

The output of the_content() is filtered through the do_shortcode, so you can just add it into your editor instead.

Running your code I get the following output for the $arguments dump:

array (size=1)
  'a' => string 'b' (length=1)

and

array (size=1)
  'a' => string 'c' (length=1)

so there's no '0' => 'bar' part here.

But you can get the current shortcode tag from the third parameter of the shortcode callback ( I first heard about it in this answer by @toscho )

I just checked the source and if we check out the do_shortcode_tag function we will find:

// self-closing tag
return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, null,  $tag ) . $m[6];

where $tag is the third parameter containing the shortcode tag.

So in your case you can change your callback to:

function foo( $attributes = array(), $content = null, $tag = '' ) {

    echo $tag; // current shortcode tag

    echo '<pre>';
    var_dump($attributes);
    echo '</pre>';
}

to get information about the current shortcode tag.

Answer 2

Shortcode callbacks get a third argument with the shortcode name. there's a note about this in the docs:

Appears to always appear as third argument as of 2.9.2.

add_shortcode('foo', 'wpse173855_shortcode');
add_shortcode('bar', 'wpse173855_shortcode');

function wpse173855_shortcode($atts, $content, $name)
{
    echo '<pre>';
    var_dump($name);
    echo '</pre>';
}

A look at the source reveals that the shortcode that was matched is always passed in.