Enclosing Shortcodes

The are two scenarios for using shortcodes:

  • The shortcode is a self-closing tag like we seen in the Basic Shortcodes section.
  • The shortcode is enclosing content.

Enclosing Content

Enclosing content with a shortcode allows manipulations on the enclosed content.

[wporg]content to manipulate[/wporg]

As seen above, all you need to do in order to enclose a section of content is add a beginning [$tag] and an end [/$tag], similar to HTML.

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Processing Enclosed Content

Lets get back to our original [[wporg]] shortcode code:

function wporg_shortcode( $atts = array(), $content = null ) {
    // do something to $content

    // always return
    return $content;
}
add_shortcode( 'wporg', 'wporg_shortcode' );

Looking at the callback function we see that we chose to accept two parameters, $atts and $content. The $content parameter is going to hold our enclosed content. We will talk about $atts later.

The default value of $content is set to null so we can differentiate between a self-closing tag and enclosing tags by using PHP function is_null().

The shortcode [$tag], including its content and the end [/$tag] will be replaced with the return value of the handler function.

Alert:
It is the responsibility of the handler function to secure the output.

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Shortcode-ception

The shortcode parser performs a single pass on the content of the post.

This means that if the $content parameter of a shortcode handler contains another shortcode, it won’t be parsed. In this example, [[shortcode]] will not be processed:

[wporg]another [shortcode] is included[/wporg]

Using shortcodes inside other shortcodes is possible by calling do_shortcode() on the final return value of the handler function.

5function wporg_shortcode( $atts = array(), $content = null ) {
	// do something to $content

	// run shortcode parser recursively
	$content = do_shortcode( $content );

	// always return
	return $content;
}
add_shortcode( 'wporg', 'wporg_shortcode' );

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Limitations

The shortcode parser is unable to handle mixing of enclosing and non-enclosing forms of the same [$tag].

[wporg] non-enclosed content [wporg]enclosed content[/wporg]

Instead of being treated as two shortcodes separated by the text “ non-enclosed content “, the parser treats this as a single shortcode enclosing “ non-enclosed content [wporg]enclosed content“.