From 7d94679ff104d7a0d0bb00e4118617d3104e8ff9 Mon Sep 17 00:00:00 2001
From: Tim Hunt <T.J.Hunt@open.ac.uk>
Date: Fri, 5 Jun 2015 15:58:18 +0100
Subject: [PATCH] MDL-50491 filters: option to disable some filters in
 filter_text.

This lets you programmatically prevent certain filters running on
certain content.

Also, I created some unit tests for the basic format_text functionality
since there did not seem to be any yet.
---
 filter/upgrade.txt                    |  2 +
 lib/filterlib.php                     | 33 ++++++----
 lib/tests/filter_manager_test.php     | 82 ++++++++++++++++++++++++
 lib/tests/weblib_format_text_test.php | 90 +++++++++++++++++++++++++++
 lib/weblib.php                        | 20 +++---
 5 files changed, 203 insertions(+), 24 deletions(-)
 create mode 100644 lib/tests/filter_manager_test.php
 create mode 100644 lib/tests/weblib_format_text_test.php

diff --git a/filter/upgrade.txt b/filter/upgrade.txt
index 2570898291a..ddfbd82c4bc 100644
--- a/filter/upgrade.txt
+++ b/filter/upgrade.txt
@@ -3,6 +3,8 @@ information provided here is intended especially for developers.
 
 === 3.0 ===
 
+* New argument $skipfilters to filter_manager::filter_text to allow applying
+  the filters with a given one omitted.
 
 * New admin setting class admin_setting_filter_types which can be used if you
   want to make the disablefilters value in your code configurable.
diff --git a/lib/filterlib.php b/lib/filterlib.php
index 3a3ce1d957a..ba447f53705 100644
--- a/lib/filterlib.php
+++ b/lib/filterlib.php
@@ -54,13 +54,13 @@ define('TEXTFILTER_EXCL_SEPARATOR', '-%-');
 class filter_manager {
     /**
      * @var moodle_text_filter[][] This list of active filters, by context, for filtering content.
-     * An array contextid => array of filter objects.
+     * An array contextid => ordered array of filter name => filter objects.
      */
     protected $textfilters = array();
 
     /**
      * @var moodle_text_filter[][] This list of active filters, by context, for filtering strings.
-     * An array contextid => array of filter objects.
+     * An array contextid => ordered array of filter name => filter objects.
      */
     protected $stringfilters = array();
 
@@ -127,9 +127,9 @@ class filter_manager {
             if (is_null($filter)) {
                 continue;
             }
-            $this->textfilters[$context->id][] = $filter;
+            $this->textfilters[$context->id][$filtername] = $filter;
             if (in_array($filtername, $this->stringfilternames)) {
-                $this->stringfilters[$context->id][] = $filter;
+                $this->stringfilters[$context->id][$filtername] = $filter;
             }
         }
     }
@@ -162,12 +162,17 @@ class filter_manager {
     /**
      * Apply a list of filters to some content.
      * @param string $text
-     * @param moodle_text_filter[] $filterchain
+     * @param moodle_text_filter[] $filterchain array filter name => filter object.
      * @param array $options options passed to the filters.
+     * @param array $skipfilters of filter names. Any filters that should not be applied to this text.
      * @return string $text
      */
-    protected function apply_filter_chain($text, $filterchain, array $options = array()) {
-        foreach ($filterchain as $filter) {
+    protected function apply_filter_chain($text, $filterchain, array $options = array(),
+            array $skipfilters = null) {
+        foreach ($filterchain as $filtername => $filter) {
+            if ($skipfilters !== null && in_array($filtername, $skipfilters)) {
+                continue;
+            }
             $text = $filter->filter($text, $options);
         }
         return $text;
@@ -205,10 +210,12 @@ class filter_manager {
      * @param string $text The text to filter
      * @param context $context the context.
      * @param array $options options passed to the filters
+     * @param array $skipfilters of filter names. Any filters that should not be applied to this text.
      * @return string resulting text
      */
-    public function filter_text($text, $context, array $options = array()) {
-        $text = $this->apply_filter_chain($text, $this->get_text_filters($context), $options);
+    public function filter_text($text, $context, array $options = array(),
+            array $skipfilters = null) {
+        $text = $this->apply_filter_chain($text, $this->get_text_filters($context), $options, $skipfilters);
         // <nolink> tags removed for XHTML compatibility
         $text = str_replace(array('<nolink>', '</nolink>'), '', $text);
         return $text;
@@ -275,7 +282,8 @@ class filter_manager {
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class null_filter_manager {
-    public function filter_text($text, $context, $options) {
+    public function filter_text($text, $context, array $options = array(),
+            array $skipfilters = null) {
         return $text;
     }
 
@@ -320,9 +328,10 @@ class performance_measuring_filter_manager extends filter_manager {
         return parent::make_filter_object($filtername, $context, $localconfig);
     }
 
-    public function filter_text($text, $context, array $options = array()) {
+    public function filter_text($text, $context, array $options = array(),
+            array $skipfilters = null) {
         $this->textsfiltered++;
-        return parent::filter_text($text, $context, $options);
+        return parent::filter_text($text, $context, $options, $skipfilters);
     }
 
     public function filter_string($string, $context) {
diff --git a/lib/tests/filter_manager_test.php b/lib/tests/filter_manager_test.php
new file mode 100644
index 00000000000..85b7632e4d3
--- /dev/null
+++ b/lib/tests/filter_manager_test.php
@@ -0,0 +1,82 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Unit tests for the {@link filter_manager} class.
+ *
+ * @package   core
+ * @category  test
+ * @copyright 2015 The Open University
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU Public License
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+
+/**
+ * Unit tests for the {@link filter_manager} class.
+ *
+ * @copyright 2015 The Open University
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU Public License
+ */
+class core_filter_manager_testcase extends advanced_testcase {
+
+    /**
+     * Helper method to apply filters to some text and return the result.
+     * @param string $text the text to filter.
+     * @param array $skipfilters any filters not to apply, even if they are configured.
+     * @return string the filtered text.
+     */
+    protected function filter_text($text, $skipfilters) {
+        global $PAGE;
+        $filtermanager = filter_manager::instance();
+        $filtermanager->setup_page_for_filters($PAGE, $PAGE->context);
+        $filteroptions = array(
+                'originalformat' => FORMAT_HTML,
+                'noclean' => false,
+        );
+        return $filtermanager->filter_text($text, $PAGE->context, $filteroptions, $skipfilters);
+    }
+
+    public function test_filter_normal() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertRegExp('~^<p><img class="emoticon" alt="smile" ([^>]+)></p>$~',
+                $this->filter_text('<p>:-)</p>', array()));
+    }
+
+    public function test_one_filter_disabled() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertEquals('<p>:-)</p>',
+                $this->filter_text('<p>:-)</p>', array('emoticon')));
+    }
+
+    public function test_disabling_other_filter_does_not_break_it() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertRegExp('~^<p><img class="emoticon" alt="smile" ([^>]+)></p>$~',
+                $this->filter_text('<p>:-)</p>', array('urltolink')));
+    }
+
+    public function test_one_filter_of_two_disabled() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        filter_set_global_state('urltolink', TEXTFILTER_ON);
+        $this->assertRegExp('~^<p><img class="emoticon" alt="smile" ([^>]+)> http://google.com/</p>$~',
+                $this->filter_text('<p>:-) http://google.com/</p>', array('glossary', 'urltolink')));
+    }
+}
diff --git a/lib/tests/weblib_format_text_test.php b/lib/tests/weblib_format_text_test.php
new file mode 100644
index 00000000000..dce2330a22b
--- /dev/null
+++ b/lib/tests/weblib_format_text_test.php
@@ -0,0 +1,90 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Unit tests for format_text defined in weblib.php.
+ *
+ * @package   core
+ * @category  test
+ * @copyright 2015 The Open University
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU Public License
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+
+/**
+ * Unit tests for format_text defined in weblib.php.
+ *
+ * @copyright 2015 The Open University
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU Public License
+ */
+class core_weblib_format_text_testcase extends advanced_testcase {
+
+    public function test_format_text_format_html() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertRegExp('~^<p><img class="emoticon" alt="smile" ([^>]+)></p>$~',
+                format_text('<p>:-)</p>', FORMAT_HTML));
+    }
+
+    public function test_format_text_format_html_no_filters() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertEquals('<p>:-)</p>',
+                format_text('<p>:-)</p>', FORMAT_HTML, array('filter' => false)));
+    }
+
+    public function test_format_text_format_plain() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertEquals(':-)',
+                format_text(':-)', FORMAT_PLAIN, array('filter' => false)));
+    }
+
+    public function test_format_text_format_markdown() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertRegExp('~^<p><em><img class="emoticon" alt="smile" ([^>]+)></em></p>\n$~',
+                format_text('*:-)*', FORMAT_MARKDOWN));
+    }
+
+    public function test_format_text_format_markdown_nofilter() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertEquals("<p><em>:-)</em></p>\n",
+                format_text('*:-)*', FORMAT_MARKDOWN, array('filter' => false)));
+    }
+
+    public function test_format_text_format_moodle() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertRegExp('~^<div class="text_to_html"><p><img class="emoticon" alt="smile" ([^>]+)></p></div>$~',
+                format_text('<p>:-)</p>', FORMAT_MOODLE));
+    }
+
+    public function test_format_text_format_moodle_no_filters() {
+        $this->resetAfterTest();
+        filter_set_global_state('emoticon', TEXTFILTER_ON);
+        $this->assertEquals('<div class="text_to_html"><p>:-)</p></div>',
+                format_text('<p>:-)</p>', FORMAT_MOODLE, array('filter' => false)));
+    }
+
+    public function test_format_text_overflowdiv() {
+        $this->assertEquals('<div class="no-overflow"><p>:-)</p></div>',
+                format_text('<p>:-)</p>', FORMAT_HTML, array('overflowdiv' => true)));
+    }
+}
diff --git a/lib/weblib.php b/lib/weblib.php
index 8f060a06552..696caa53e0c 100644
--- a/lib/weblib.php
+++ b/lib/weblib.php
@@ -1204,8 +1204,13 @@ function format_text($text, $format = FORMAT_MOODLE, $options = null, $courseidd
     if ($options['filter']) {
         $filtermanager = filter_manager::instance();
         $filtermanager->setup_page_for_filters($PAGE, $context); // Setup global stuff filters may have.
+        $filteroptions = array(
+            'originalformat' => $format,
+            'noclean' => $options['noclean'],
+        );
     } else {
         $filtermanager = new null_filter_manager();
+        $filteroptions = array();
     }
 
     switch ($format) {
@@ -1213,10 +1218,7 @@ function format_text($text, $format = FORMAT_MOODLE, $options = null, $courseidd
             if (!$options['noclean']) {
                 $text = clean_text($text, FORMAT_HTML, $options);
             }
-            $text = $filtermanager->filter_text($text, $context, array(
-                'originalformat' => FORMAT_HTML,
-                'noclean' => $options['noclean']
-            ));
+            $text = $filtermanager->filter_text($text, $context, $filteroptions);
             break;
 
         case FORMAT_PLAIN:
@@ -1239,10 +1241,7 @@ function format_text($text, $format = FORMAT_MOODLE, $options = null, $courseidd
             if (!$options['noclean']) {
                 $text = clean_text($text, FORMAT_HTML, $options);
             }
-            $text = $filtermanager->filter_text($text, $context, array(
-                'originalformat' => FORMAT_MARKDOWN,
-                'noclean' => $options['noclean']
-            ));
+            $text = $filtermanager->filter_text($text, $context, $filteroptions);
             break;
 
         default:  // FORMAT_MOODLE or anything else.
@@ -1250,10 +1249,7 @@ function format_text($text, $format = FORMAT_MOODLE, $options = null, $courseidd
             if (!$options['noclean']) {
                 $text = clean_text($text, FORMAT_HTML, $options);
             }
-            $text = $filtermanager->filter_text($text, $context, array(
-                'originalformat' => $format,
-                'noclean' => $options['noclean']
-            ));
+            $text = $filtermanager->filter_text($text, $context, $filteroptions);
             break;
     }
     if ($options['filter']) {