From 7e4e9f1ce7ef3d29228873b758f37ebdc8a2d735 Mon Sep 17 00:00:00 2001
From: Gary Pendergast <pento@git.wordpress.org>
Date: Tue, 4 Oct 2016 00:38:45 +0000
Subject: [PATCH] Shortcodes: Add a `do_shortcode_tag` filter.

The addition of the `pre_do_shortcode_tag` in [38506] allows plugins to short-circuit the shortcode execution process, which is particularly helpful for caching expensive shortcodes.

The `do_shortcode_tag` is the corresponding part of that system - when a shortcode hasn't been executed previously, there needs to be a clean method of populating the cache.

Props flixos90.
Fixes #32790.



git-svn-id: https://develop.svn.wordpress.org/trunk@38713 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/shortcodes.php    | 22 ++++++----
 tests/phpunit/tests/shortcode.php | 69 ++++++++++++++++++++++++++++++-
 2 files changed, 83 insertions(+), 8 deletions(-)

diff --git a/src/wp-includes/shortcodes.php b/src/wp-includes/shortcodes.php
index b2aad3dc4d..f0523622cc 100644
--- a/src/wp-includes/shortcodes.php
+++ b/src/wp-includes/shortcodes.php
@@ -339,13 +339,21 @@ function do_shortcode_tag( $m ) {
 		return $return;
 	}
 
-	if ( isset( $m[5] ) ) {
-		// enclosing tag - extra parameter
-		return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, $m[5], $tag ) . $m[6];
-	} else {
-		// self-closing tag
-		return $m[1] . call_user_func( $shortcode_tags[$tag], $attr, null,  $tag ) . $m[6];
-	}
+	$content = isset( $m[5] ) ? $m[5] : null;
+
+	$output = $m[1] . call_user_func( $shortcode_tags[ $tag ], $attr, $content, $tag ) . $m[6];
+
+	/**
+	 * Filters the output created by a shortcode callback.
+	 *
+	 * @since 4.7.0
+	 *
+	 * @param string $output Shortcode output.
+	 * @param string $tag    Shortcode name.
+	 * @param array  $attr   Shortcode attributes array,
+	 * @param array  $m      Regular expression match array.
+	 */
+	return apply_filters( 'do_shortcode_tag', $output, $tag, $attr, $m );
 }
 
 /**
diff --git a/tests/phpunit/tests/shortcode.php b/tests/phpunit/tests/shortcode.php
index f5e8ae2d9c..e807f9539e 100644
--- a/tests/phpunit/tests/shortcode.php
+++ b/tests/phpunit/tests/shortcode.php
@@ -719,7 +719,7 @@ EOF;
 		remove_filter( 'pre_do_shortcode_tag', array( $this, '_filter_pre_do_shortcode_tag_attr' ), 12, 4 );
 		remove_filter( 'pre_do_shortcode_tag', array( $this, '_filter_pre_do_shortcode_tag_p11' ), 11 );
 		remove_filter( 'pre_do_shortcode_tag', array( $this, '_filter_pre_do_shortcode_tag_bar' ) );
-		remove_shortcode( $str, array( $this, '_shortcode_pre_do_shortcode_tag' ) );
+		remove_shortcode( $str );
 	}
 
 	public function _shortcode_pre_do_shortcode_tag( $atts = array(), $content = '' ) {
@@ -743,4 +743,71 @@ EOF;
 		);
 		return wp_json_encode( $arr );
 	}
+
+	/**
+	 * @ticket 32790
+	 */
+	public function test_do_shortcode_tag_filter() {
+		// does nothing if no filters are set up
+		$str = 'do_shortcode_tag';
+		add_shortcode( $str, array( $this, '_shortcode_do_shortcode_tag' ) );
+		$result_nofilter = do_shortcode( "[{$str}]" );
+		$this->assertSame( 'foo', $result_nofilter );
+
+		// modify output with filter
+		add_filter( 'do_shortcode_tag', array( $this, '_filter_do_shortcode_tag_replace' ) );
+		$result_filter = do_shortcode( "[{$str}]" );
+		$this->assertSame( 'fee', $result_filter );
+
+		// respect priority
+		add_filter( 'do_shortcode_tag', array( $this, '_filter_do_shortcode_tag_generate' ), 11 );
+		$result_priority = do_shortcode( "[{$str}]" );
+		$this->assertSame( 'foobar', $result_priority );
+
+		// pass arguments
+		$arr = array(
+			'return' => 'foobar',
+			'key'    => $str,
+			'atts'   => array( 'a' => 'b', 'c' => 'd' ),
+			'm'      => array(
+				"[{$str} a='b' c='d']",
+				"",
+				$str,
+				" a='b' c='d'",
+				"",
+				"",
+				"",
+			),
+		);
+		add_filter( 'do_shortcode_tag', array( $this, '_filter_do_shortcode_tag_attr' ), 12, 4 );
+		$result_atts = do_shortcode( "[{$str} a='b' c='d']" );
+		$this->assertSame( wp_json_encode( $arr ), $result_atts );
+
+		remove_filter( 'do_shortcode_tag', array( $this, '_filter_do_shortcode_tag_attr' ), 12 );
+		remove_filter( 'do_shortcode_tag', array( $this, '_filter_do_shortcode_tag_generate' ), 11 );
+		remove_filter( 'do_shortcode_tag', array( $this, '_filter_do_shortcode_tag_replace' ) );
+		remove_shortcode( $str );
+	}
+
+	public function _shortcode_do_shortcode_tag( $atts = array(), $content = '' ) {
+		return 'foo';
+	}
+
+	public function _filter_do_shortcode_tag_replace( $return ) {
+		return str_replace( 'oo', 'ee', $return );
+	}
+
+	public function _filter_do_shortcode_tag_generate( $return ) {
+		return 'foobar';
+	}
+
+	public function _filter_do_shortcode_tag_attr( $return, $key, $atts, $m ){
+		$arr = array(
+			'return' => $return,
+			'key'    => $key,
+			'atts'   => $atts,
+			'm'      => $m,
+		);
+		return wp_json_encode( $arr );
+	}
 }