MDL-66667 course: add course image cache

course/classes/cache/course_image.php

@@ -0,0 +1,102 @@
+<?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/>.
+
+namespace core_course\cache;
+
+use cache_data_source;
+use cache_definition;
+use moodle_url;
+use core_course_list_element;
+
+/**
+ * Class to describe cache data source for course image.
+ *
+ * @package    core
+ * @subpackage course
+ * @author     Dmitrii Metelkin <dmitriim@catalyst-au.net>
+ * @copyright  2021 Catalyst IT
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class course_image implements cache_data_source {
+
+    /** @var course_image */
+    protected static $instance = null;
+
+    /**
+     * Returns an instance of the data source class that the cache can use for loading data using the other methods
+     * specified by this interface.
+     *
+     * @param cache_definition $definition
+     * @return \core_course\cache\course_image
+     */
+    public static function get_instance_for_cache(cache_definition $definition): course_image {
+        if (is_null(self::$instance)) {
+            self::$instance = new course_image();
+        }
+        return self::$instance;
+    }
+
+    /**
+     * Loads the data for the key provided ready formatted for caching.
+     *
+     * @param string|int $key The key to load.
+     * @return string|bool Returns course image url as a string or false if the image is not exist
+     */
+    public function load_for_cache($key) {
+        $course = get_fast_modinfo($key)->get_course();
+        return $this->get_image_url_from_overview_files($course);
+    }
+
+    /**
+     * Returns image URL from course overview files.
+     *
+     * @param \stdClass $course Course object.
+     * @return null|string Image URL or null if it's not exists.
+     */
+    protected function get_image_url_from_overview_files(\stdClass $course): ?string {
+        $courseinlist = new core_course_list_element($course);
+        foreach ($courseinlist->get_course_overviewfiles() as $file) {
+            if ($file->is_valid_image()) {
+                return moodle_url::make_pluginfile_url(
+                    $file->get_contextid(),
+                    $file->get_component(),
+                    $file->get_filearea(),
+                    null,
+                    $file->get_filepath(),
+                    $file->get_filename()
+                )->out();
+            }
+        }
+
+        // Returning null if no image found to let it be cached
+        // as false is what cache API returns then a data is not found in cache.
+        return null;
+    }
+
+    /**
+     * Loads several keys for the cache.
+     *
+     * @param array $keys An array of keys each of which will be string|int.
+     * @return array An array of matching data items.
+     */
+    public function load_many_for_cache(array $keys): array {
+        $records = [];
+        foreach ($keys as $key) {
+            $records[$key] = $this->load_for_cache($key);
+        }
+        return $records;
+    }
+}

course/classes/external/course_summary_exporter.php

@@ -165,24 +165,16 @@ public static function define_other_properties() {
      * Get the course image if added to course.
      *
      * @param object $course
-     * @return string url of course image
+     * @return string|false url of course image or false if it's not exist.
      */
     public static function get_course_image($course) {
-        global $CFG;
-        $courseinlist = new \core_course_list_element($course);
-        foreach ($courseinlist->get_course_overviewfiles() as $file) {
-            if ($file->is_valid_image()) {
-                $pathcomponents = [
-                    '/pluginfile.php',
-                    $file->get_contextid(),
-                    $file->get_component(),
-                    $file->get_filearea() . $file->get_filepath() . $file->get_filename()
-                ];
-                $path = implode('/', $pathcomponents);
-                return (new moodle_url($path))->out();
-            }
+        $image = \cache::make('core', 'course_image')->get($course->id);
+
+        if (is_null($image)) {
+            $image = false;
         }
-        return false;
+
+        return $image;
     }
 
     /**

course/lib.php

@@ -2551,6 +2551,9 @@ function update_course($data, $editoroptions = NULL) {
     // make sure the modinfo cache is reset
     rebuild_course_cache($data->id);
 
+    // Purge course image cache in case if course image has been updated.
+    \cache::make('core', 'course_image')->delete($data->id);
+
     // update course format options with full course data
     course_get_format($data->id)->update_course_format_options($data, $oldcourse);
 

course/tests/course_image_cache_test.php

@@ -0,0 +1,176 @@
+<?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/>.
+
+namespace tests\core_course;
+
+use context_user;
+use context_course;
+use ReflectionMethod;
+use cache_definition;
+use core_course\cache\course_image;
+
+/**
+ * Functional test for class course_image
+ *
+ * @package    core
+ * @subpackage course
+ * @author     Dmitrii Metelkin <dmitriim@catalyst-au.net>
+ * @copyright  2021 Catalyst IT
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class course_image_cache_testcase extends \advanced_testcase {
+
+    /**
+     * Initial setup.
+     */
+    protected function setUp(): void {
+        global $CFG;
+
+        parent::setUp();
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        // Allow multiple overview files.
+        $CFG->courseoverviewfileslimit = 3;
+    }
+
+    /**
+     * Helper method to create a draft area for current user and fills it with fake files
+     *
+     * @param array $files array of files that need to be added to filearea, filename => filecontents
+     * @return int draftid for the filearea
+     */
+    protected function fill_draft_area(array $files): int {
+        global $USER;
+
+        $draftid = file_get_unused_draft_itemid();
+        foreach ($files as $filename => $filecontents) {
+            // Add actual file there.
+            $filerecord = [
+                'component' => 'user',
+                'filearea' => 'draft',
+                'contextid' => context_user::instance($USER->id)->id, 'itemid' => $draftid,
+                'filename' => $filename, 'filepath' => '/'
+            ];
+            $fs = get_file_storage();
+            $fs->create_file_from_string($filerecord, $filecontents);
+        }
+        return $draftid;
+    }
+
+    /**
+     * A helper method to generate expected file URL.
+     *
+     * @param \stdClass $course Course object.
+     * @param string $filename File name.
+     * @return string
+     */
+    protected function build_expected_course_image_url(\stdClass $course, string $filename): string {
+        $contextid = context_course::instance($course->id)->id;
+        return 'https://www.example.com/moodle/pluginfile.php/' . $contextid. '/course/overviewfiles/' . $filename;
+    }
+
+    /**
+     * Test exception if try to get an image for non existing course.
+     */
+    public function test_getting_data_if_course_is_not_exist() {
+        $this->expectException('dml_missing_record_exception');
+        $this->expectExceptionMessageMatches("/Can't find data record in database table course./");
+        $this->assertFalse(\cache::make('core', 'course_image')->get(999));
+    }
+
+    /**
+     * Test get_image_url_from_overview_files when no summary files in the course.
+     */
+    public function test_get_image_url_from_overview_files_return_null_if_no_summary_files_in_the_course() {
+        $method = new ReflectionMethod(course_image::class, 'get_image_url_from_overview_files');
+        $cache = course_image::get_instance_for_cache(new cache_definition());
+        $method->setAccessible(true);
+
+        // Create course without files.
+        $course = $this->getDataGenerator()->create_course();
+        $this->assertNull($method->invokeArgs($cache, [$course]));
+    }
+
+    /**
+     * Test get_image_url_from_overview_files when no summary images in the course.
+     */
+    public function test_get_image_url_from_overview_files_returns_null_if_no_summary_images_in_the_course() {
+        $method = new ReflectionMethod(course_image::class, 'get_image_url_from_overview_files');
+        $cache = course_image::get_instance_for_cache(new cache_definition());
+        $method->setAccessible(true);
+
+        // Create course without image files.
+        $draftid2 = $this->fill_draft_area(['filename2.zip' => 'Test file contents2']);
+        $course2 = $this->getDataGenerator()->create_course(['overviewfiles_filemanager' => $draftid2]);
+        $this->assertNull($method->invokeArgs($cache, [$course2]));
+    }
+
+    /**
+     * Test get_image_url_from_overview_files when no summary images in the course.
+     */
+    public function test_get_image_url_from_overview_files_returns_url_if_there_is_a_summary_image() {
+        $method = new ReflectionMethod(course_image::class, 'get_image_url_from_overview_files');
+        $cache = course_image::get_instance_for_cache(new cache_definition());
+        $method->setAccessible(true);
+
+        // Create course without one image.
+        $draftid1 = $this->fill_draft_area(['filename1.jpg' => file_get_contents(__DIR__ . '/fixtures/image.jpg')]);
+        $course1 = $this->getDataGenerator()->create_course(['overviewfiles_filemanager' => $draftid1]);
+        $expected = $this->build_expected_course_image_url($course1, 'filename1.jpg');
+        $this->assertEquals($expected, $method->invokeArgs($cache, [$course1]));
+    }
+
+    /**
+     * Test get_image_url_from_overview_files when several summary images in the course.
+     */
+    public function test_get_image_url_from_overview_files_returns_url_of_the_first_image_if_there_are_many_summary_images() {
+        $method = new ReflectionMethod(course_image::class, 'get_image_url_from_overview_files');
+        $cache = course_image::get_instance_for_cache(new cache_definition());
+        $method->setAccessible(true);
+
+        // Create course with two image files.
+        $draftid1 = $this->fill_draft_area([
+            'filename1.jpg' => file_get_contents(__DIR__ . '/fixtures/image.jpg'),
+            'filename2.jpg' => file_get_contents(__DIR__ . '/fixtures/image.jpg'),
+        ]);
+        $course1 = $this->getDataGenerator()->create_course(['overviewfiles_filemanager' => $draftid1]);
+
+        $expected = $this->build_expected_course_image_url($course1, 'filename1.jpg');
+        $this->assertEquals($expected, $method->invokeArgs($cache, [$course1]));
+    }
+
+    /**
+     * Test get_image_url_from_overview_files when several summary files in the course.
+     */
+    public function test_get_image_url_from_overview_files_returns_url_of_the_first_image_if_there_are_many_summary_files() {
+        $method = new ReflectionMethod(course_image::class, 'get_image_url_from_overview_files');
+        $cache = course_image::get_instance_for_cache(new cache_definition());
+        $method->setAccessible(true);
+
+        // Create course with two image files and one zip file.
+        $draftid1 = $this->fill_draft_area([
+            'filename1.zip' => 'Test file contents2',
+            'filename2.jpg' => file_get_contents(__DIR__ . '/fixtures/image.jpg'),
+            'filename3.jpg' => file_get_contents(__DIR__ . '/fixtures/image.jpg'),
+        ]);
+        $course1 = $this->getDataGenerator()->create_course(['overviewfiles_filemanager' => $draftid1]);
+
+        $expected = $this->build_expected_course_image_url($course1, 'filename2.jpg');
+        $this->assertEquals($expected, $method->invokeArgs($cache, [$course1]));
+    }
+
+}

course/tests/course_summary_exporter_test.php

@@ -0,0 +1,73 @@
+<?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/>.
+
+namespace tests\core_course;
+
+use core_course\external\course_summary_exporter;
+use context_user;
+use context_course;
+
+/**
+ * Functional test for class course_summary_exporter
+ *
+ * @package    core
+ * @subpackage course
+ * @author     Dmitrii Metelkin <dmitriim@catalyst-au.net>
+ * @copyright  2021 Catalyst IT
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class course_summary_exporter_testcase extends \advanced_testcase {
+
+    /**
+     * Test that if no course overview images uploaded get_course_image returns false.
+     */
+    public function test_get_course_image_when_no_overview_images_uploaded() {
+        $this->resetAfterTest(true);
+        $this->setAdminUser();
+        $course = $this->getDataGenerator()->create_course();
+
+        $this->assertFalse(course_summary_exporter::get_course_image($course));
+    }
+
+    /**
+     * Test that if course overview images uploaded get_course_image returns an image URL.
+     */
+    public function test_get_course_image_when_overview_images_are_uploaded() {
+        global $USER;
+
+        $this->resetAfterTest(true);
+        $this->setAdminUser();
+
+        $draftid = file_get_unused_draft_itemid();
+        $filerecord = [
+            'component' => 'user',
+            'filearea' => 'draft',
+            'contextid' => context_user::instance($USER->id)->id,
+            'itemid' => $draftid,
+            'filename' => 'image.jpg',
+            'filepath' => '/',
+        ];
+        $fs = get_file_storage();
+        $fs->create_file_from_string($filerecord, file_get_contents(__DIR__ . '/fixtures/image.jpg'));
+        $course = $this->getDataGenerator()->create_course(['overviewfiles_filemanager' => $draftid]);
+        $coursecontext = context_course::instance($course->id);
+
+        $expected = 'https://www.example.com/moodle/pluginfile.php/' . $coursecontext->id . '/course/overviewfiles/image.jpg';
+        $actual = course_summary_exporter::get_course_image($course);
+        $this->assertSame($expected, $actual);
+    }
+
+}