MDL-70815 core_completion: Activity custom completion details base class

* Base class for defining an activity module's custom completion details

completion/classes/activity_custom_completion.php

@@ -0,0 +1,175 @@
+<?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/>.
+
+declare(strict_types = 1);
+
+namespace core_completion;
+
+use cm_info;
+use coding_exception;
+use moodle_exception;
+
+/**
+ * Base class for defining an activity module's custom completion rules.
+ *
+ * Class for defining an activity module's custom completion rules and fetching the completion statuses
+ * of the custom completion rules for a given module instance and a user.
+ *
+ * @package   core_completion
+ * @copyright 2021 Jun Pataleta <jun@moodle.com>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+abstract class activity_custom_completion {
+
+    /** @var cm_info The course module information object. */
+    protected $cm;
+
+    /** @var int The user's ID. */
+    protected $userid;
+
+    /**
+     * activity_custom_completion constructor.
+     *
+     * @param cm_info $cm
+     * @param int $userid
+     */
+    public function __construct(cm_info $cm, int $userid) {
+        $this->cm = $cm;
+        $this->userid = $userid;
+    }
+
+    /**
+     * Validates that the custom rule is defined by this plugin and is enabled for this activity instance.
+     *
+     * @param string $rule The custom completion rule.
+     */
+    public function validate_rule(string $rule): void {
+        // Check that this custom completion rule is defined.
+        if (!$this->is_defined($rule)) {
+            throw new coding_exception("Undefined custom completion rule '$rule'");
+        }
+
+        // Check that this custom rule is included in the course module's custom completion rules.
+        if (!$this->is_available($rule)) {
+            throw new moodle_exception("Custom completion rule '$rule' is not used by this activity.");
+        }
+    }
+
+    /**
+     * Whether this module defines this custom rule.
+     *
+     * @param string $rule The custom completion rule.
+     * @return bool
+     */
+    public function is_defined(string $rule): bool {
+        return in_array($rule, static::get_defined_custom_rules());
+    }
+
+    /**
+     * Checks whether the custom completion rule is being used by the activity module instance.
+     *
+     * @param string $rule The custom completion rule.
+     * @return bool
+     */
+    public function is_available(string $rule): bool {
+        return in_array($rule, $this->get_available_custom_rules());
+    }
+
+    /**
+     * Fetches the list of custom completion rules that are being used by this activity module instance.
+     *
+     * @return array
+     */
+    public function get_available_custom_rules(): array {
+        $rules = static::get_defined_custom_rules();
+        $availablerules = [];
+        foreach ($rules as $rule) {
+            $customrule = $this->cm->customdata['customcompletionrules'][$rule] ?? false;
+            if (!empty($customrule)) {
+                $availablerules[] = $rule;
+            }
+        }
+        return $availablerules;
+    }
+
+    /**
+     * Fetches the overall completion status of this activity instance for a user based on its available custom completion rules.
+     *
+     * @return int The completion state (e.g. COMPLETION_COMPLETE, COMPLETION_INCOMPLETE).
+     */
+    public function get_overall_completion_state(): int {
+        foreach ($this->get_available_custom_rules() as $rule) {
+            $state = $this->get_state($rule);
+            // Return early if one of the custom completion rules is not yet complete.
+            if ($state == COMPLETION_INCOMPLETE) {
+                return $state;
+            }
+        }
+        // If this was reached, then all custom rules have been marked complete.
+        return COMPLETION_COMPLETE;
+    }
+
+    /**
+     * Fetches the description for a given custom completion rule.
+     *
+     * @param string $rule The custom completion rule.
+     * @return string
+     */
+    public function get_custom_rule_description(string $rule): string {
+        $descriptions = $this->get_custom_rule_descriptions();
+        if (!isset($descriptions[$rule])) {
+            // Lang string not found for this custom completion rule. Just return it.
+            return $rule;
+        }
+        return $descriptions[$rule];
+    }
+
+    /**
+     * Fetches the module's custom completion class implementation if it's available.
+     *
+     * @param string $modname The activity module name. Usually from cm_info::modname.
+     * @return string|null
+     */
+    public static function get_cm_completion_class(string $modname): ?string {
+        $cmcompletionclass = "mod_{$modname}\\completion\\custom_completion";
+        if (class_exists($cmcompletionclass) && is_subclass_of($cmcompletionclass, self::class)) {
+            return $cmcompletionclass;
+        }
+        return null;
+    }
+
+    /**
+     * Fetches the completion state for a given completion rule.
+     *
+     * @param string $rule The completion rule.
+     * @return int The completion state.
+     */
+    public abstract function get_state(string $rule): int;
+
+    /**
+     * Fetch the list of custom completion rules that this module defines.
+     *
+     * @return array
+     */
+    public abstract static function get_defined_custom_rules(): array;
+
+    /**
+     * Returns an associative array of the descriptions of custom completion rules.
+     *
+     * @return array
+     */
+    public abstract function get_custom_rule_descriptions(): array;
+}

lib/upgrade.txt

@@ -33,6 +33,15 @@ information provided here is intended especially for developers.
 * New DML driver method `$DB->sql_group_concat` for performing group concatenation of a field within a SQL query
 * Added new class, AMD modules and WS that allow displaying forms in modal popups or load and submit in AJAX requests.
   See https://docs.moodle.org/dev/Modal_and_AJAX_forms for more details.
+* New base class for defining an activity's custom completion requirements: \core_completion\activity_custom_completion.
+  Activity module plugins that define custom completion conditions should implement a mod_[modname]\completion\custom_completion
+  subclass and the following methods:
+  - get_state(): Provides the completion state for a given custom completion rule.
+  - get_defined_custom_rules(): Returns an array of the activity module's custom completion rules.
+    e.g. ['completionsubmit']
+  - get_custom_rule_descriptions(): Returns an associative array with values containing the user-facing textual description
+    of the custom completion rules (which serve as the keys to these values).
+    e.g. ['completionsubmit' => 'Must submit']
 
 === 3.10 ===
 * PHPUnit has been upgraded to 8.5. That comes with a few changes: