MDL-62309 tool_policy: Add api::get_agreement_optional() method

This method allows to quickly check if the given policy version is
marked as optional or compulsory. This will be needed in other places
such as permissions check.

admin/tool/policy/classes/api.php

@@ -131,6 +131,8 @@ class api {
 
         $policies = [];
         $versions = [];
+        $optcache = \cache::make('tool_policy', 'policy_optional');
+
         $rs = $DB->get_recordset_sql($sql, $params);
 
         foreach ($rs as $r) {
@@ -149,6 +151,8 @@ class api {
             }
 
             $versions[$r->id][$versiondata->id] = $versiondata;
+
+            $optcache->set($versiondata->id, $versiondata->optional);
         }
 
         $rs->close();
@@ -1040,4 +1044,29 @@ class api {
             $DB->insert_records('tool_policy_acceptances', $acceptances);
         }
     }
+
+    /**
+     * Returns the value of the optional flag for the given policy version.
+     *
+     * Optimised for being called multiple times by making use of a request cache. The cache is normally populated as a
+     * side effect of calling {@link self::list_policies()} and in most cases should be warm enough for hits.
+     *
+     * @param int $versionid
+     * @return int policy_version::AGREEMENT_COMPULSORY | policy_version::AGREEMENT_OPTIONAL
+     */
+    public static function get_agreement_optional($versionid) {
+        global $DB;
+
+        $optcache = \cache::make('tool_policy', 'policy_optional');
+
+        $hit = $optcache->get($versionid);
+
+        if ($hit === false) {
+            $flags = $DB->get_records_menu('tool_policy_versions', null, '', 'id, optional');
+            $optcache->set_many($flags);
+            $hit = $flags[$versionid];
+        }
+
+        return $hit;
+    }
 }

admin/tool/policy/classes/policy_version.php

@@ -168,4 +168,26 @@ class policy_version extends persistent {
             ],
         ];
     }
+
+    /**
+     * Hook to execute after an update.
+     *
+     * @param bool $result Whether or not the update was successful (but it always is)
+     */
+    protected function after_update($result) {
+
+        $optcache = \cache::make('tool_policy', 'policy_optional');
+        $optcache->delete($this->raw_get('id'));
+    }
+
+    /**
+     * Hook to execute after an update.
+     *
+     * @param bool $result Whether or not the update was successful (but it always is)
+     */
+    protected function after_delete($result) {
+
+        $optcache = \cache::make('tool_policy', 'policy_optional');
+        $optcache->delete($this->raw_get('id'));
+    }
 }

admin/tool/policy/db/caches.php

@@ -0,0 +1,32 @@
+<?php
+// This file is part of Moodle - https://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/>.
+
+/**
+ * Defined caches used internally by the plugin.
+ *
+ * @package     tool_policy
+ * @category    cache
+ * @copyright   2018 David Mudrák <david@moodle.com>
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+$definitions = [
+    'policy_optional' => [
+        'mode' => cache_store::MODE_REQUEST,
+    ],
+];

admin/tool/policy/lang/en/tool_policy.php

@@ -52,6 +52,7 @@ $string['agreedyeswithlinkall'] = 'Consent given; click to withdraw user consent
 $string['agreepolicies'] = 'Please agree to the following policies';
 $string['backtoprevious'] = 'Go back to previous page';
 $string['backtotop'] = 'Back to top';
+$string['cachedef_policy_optional'] = 'Cache of the optional/compulsory flag for policy versions';
 $string['consentbulk'] = 'Consent';
 $string['consentdetails'] = 'Give consent on behalf of user(s)';
 $string['consentpagetitle'] = 'Consent';

admin/tool/policy/tests/api_test.php

@@ -668,4 +668,21 @@ class tool_policy_api_testcase extends advanced_testcase {
         $this->assertFalse(api::is_user_version_accepted(13, 6, $preloadedacceptances));
         $this->assertNull(api::is_user_version_accepted(13, 5, $preloadedacceptances));
     }
+
+    /**
+     * Test the functionality of {@link api::get_agreement_optional()}.
+     */
+    public function test_get_agreement_optional() {
+        global $DB;
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        $policy1 = $this->add_policy(['optional' => policy_version::AGREEMENT_OPTIONAL])->to_record();
+        api::make_current($policy1->id);
+        $policy2 = $this->add_policy(['optional' => policy_version::AGREEMENT_COMPULSORY])->to_record();
+        api::make_current($policy2->id);
+
+        $this->assertEquals(api::get_agreement_optional($policy1->id), policy_version::AGREEMENT_OPTIONAL);
+        $this->assertEquals(api::get_agreement_optional($policy2->id), policy_version::AGREEMENT_COMPULSORY);
+    }
 }

admin/tool/policy/version.php

@@ -24,6 +24,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2018091800;         // The current plugin version (Date: YYYYMMDDXX).
+$plugin->version   = 2018100100;         // The current plugin version (Date: YYYYMMDDXX).
 $plugin->requires  = 2018050800;         // Requires this Moodle version.
 $plugin->component = 'tool_policy';      // Full name of the plugin (used for diagnostics).