competency_framework.php

<?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/>.

/**
 * Class for loading/storing competency frameworks from the DB.
 *
 * @package    tool_lp
 * @copyright  2015 Damyon Wiese
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
namespace tool_lp;

use context;
use lang_string;
use stdClass;

/**
 * Class for loading/storing competency frameworks from the DB.
 *
 * @copyright  2015 Damyon Wiese
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class competency_framework extends persistent {

    const TABLE = 'tool_lp_competency_framework';

    /** Taxonomy constant. */
    const TAXONOMY_BEHAVIOUR = 'behaviour';
    /** Taxonomy constant. */
    const TAXONOMY_COMPETENCY = 'competency';
    /** Taxonomy constant. */
    const TAXONOMY_CONCEPT = 'concept';
    /** Taxonomy constant. */
    const TAXONOMY_DOMAIN = 'domain';
    /** Taxonomy constant. */
    const TAXONOMY_INDICATOR = 'indicator';
    /** Taxonomy constant. */
    const TAXONOMY_LEVEL = 'level';
    /** Taxonomy constant. */
    const TAXONOMY_OUTCOME = 'outcome';
    /** Taxonomy constant. */
    const TAXONOMY_PRACTICE = 'practice';
    /** Taxonomy constant. */
    const TAXONOMY_PROFICIENCY = 'proficiency';
    /** Taxonomy constant. */
    const TAXONOMY_SKILL = 'skill';
    /** Taxonomy constant. */
    const TAXONOMY_VALUE = 'value';

    /**
     * Get the context.
     *
     * @return context The context
     */
    public function get_context() {
        return context::instance_by_id($this->get_contextid());
    }

    /**
     * Return the definition of the properties of this model.
     *
     * @return array
     */
    protected static function define_properties() {
        return array(
            'shortname' => array(
                'type' => PARAM_TEXT
            ),
            'idnumber' => array(
                'type' => PARAM_TEXT
            ),
            'description' => array(
                'type' => PARAM_TEXT,
                'default' => ''
            ),
            'descriptionformat' => array(
                'choices' => array(FORMAT_HTML, FORMAT_MOODLE, FORMAT_PLAIN, FORMAT_MARKDOWN),
                'type' => PARAM_INT,
                'default' => FORMAT_HTML
            ),
            'visible' => array(
                'type' => PARAM_BOOL,
                'default' => 1
            ),
            // TODO MDL-51442 make this mandatory.
            'scaleid' => array(
                'type' => PARAM_INT,
                'default' => 0
            ),
            // TODO MDL-51442 make this mandatory.
            'scaleconfiguration' => array(
                'type' => PARAM_RAW,
                'default' => ''
            ),
            'contextid' => array(
                'type' => PARAM_INT
            ),
            'taxonomies' => array(
                'type' => PARAM_RAW,
                'default' => ''
            )
        );
    }

    /**
     * Get the translated name for a level.
     *
     * @param  int $level The level of the term.
     * @return lang_string
     */
    public function get_taxonomy($level) {
        $taxonomies = $this->get_taxonomies();

        if (empty($taxonomies[$level])) {
            // If for some reason we cannot find the level, we fallback onto competency.
            $constant = self::TAXONOMY_COMPETENCY;
        } else {
            $constant = $taxonomies[$level];
        }

        return self::get_taxonomy_from_constant($constant);
    }

    /**
     * Return the taxonomy constants indexed by level.
     *
     * @return array Contains the list of taxonomy constants indexed by level.
     */
    public function get_taxonomies() {
        $taxonomies = explode(',', $this->get('taxonomies'));

        // Indexing first level at 1.
        array_unshift($taxonomies, null);
        unset($taxonomies[0]);

        // Ensure that we do not return empty levels.
        for ($i = 1; $i <= self::get_taxonomies_max_level(); $i++) {
            if (empty($taxonomies[$i])) {
                $taxonomies[$i] = self::TAXONOMY_COMPETENCY;
            }
        }

        return $taxonomies;
    }

    /**
     * Convenience method to set taxonomies from an array or string.
     *
     * @param string|array $taxonomies A string, or an array where the values are the term constants.
     */
    public function set_taxonomies($taxonomies) {
        if (is_array($taxonomies)) {
            $taxonomies = implode(',', $taxonomies);
        }
        $this->set('taxonomies', $taxonomies);
    }

    /**
     * Validate the context ID.
     *
     * @param  int $value The context ID.
     * @return bool|lang_string
     */
    public function validate_contextid($value) {
        global $DB;

        $context = context::instance_by_id($value, IGNORE_MISSING);
        if (!$context) {
            return new lang_string('invalidcontext', 'error');
        } else if ($context->contextlevel != CONTEXT_SYSTEM && $context->contextlevel != CONTEXT_COURSECAT) {
            return new lang_string('invalidcontext', 'error');
        }

        // During update.
        if ($this->get_id()) {

            // The context must never change.
            $oldcontextid = $DB->get_field(self::TABLE, 'contextid', array('id' => $this->get_id()), MUST_EXIST);
            if ($this->get_contextid() != $oldcontextid) {
                return new lang_string('invalidcontext', 'error');
            }
        }

        return true;
    }

    /**
     * Validate taxonomies.
     *
     * @param  mixed $value The taxonomies.
     * @return true|lang_string
     */
    protected function validate_taxonomies($value) {
        $terms = explode(',', $value);

        if (count($terms) > self::get_taxonomies_max_level()) {
            return new lang_string('invaliddata', 'error');
        }

        foreach ($terms as $term) {
            if (!empty($term) && !array_key_exists($term, self::get_taxonomies_list())) {
                return new lang_string('invalidtaxonomy', 'tool_lp', $term);
            }
        }

        return true;
    }

    /**
     * Get the string of a taxonomy from a constant
     *
     * @param  string $constant The taxonomy constant.
     * @return lang_string
     */
    public static function get_taxonomy_from_constant($constant) {
        return self::get_taxonomies_list()[$constant];
    }

    /**
     * Return the maximum number of taxonomy levels.
     *
     * This is a method and not a constant because we want to make it easy to adapt
     * to the number of levels desired in the future.
     *
     * @return int
     */
    public static function get_taxonomies_max_level() {
        return 4;
    }

    /**
     * Get the list of all taxonomies.
     *
     * @return array Where the key is the taxonomy constant, and the value its translation.
     */
    public static function get_taxonomies_list() {
        static $list = null;

        // At some point we'll have to switch to not using static cache, mainly for Unit Tests in case we
        // decide to allow more taxonomies to be added dynamically from a CFG variable for instance.
        if ($list === null) {
            $list = array(
                self::TAXONOMY_BEHAVIOUR => new lang_string('taxonomy_' . self::TAXONOMY_BEHAVIOUR, 'tool_lp'),
                self::TAXONOMY_COMPETENCY => new lang_string('taxonomy_' . self::TAXONOMY_COMPETENCY, 'tool_lp'),
                self::TAXONOMY_CONCEPT => new lang_string('taxonomy_' . self::TAXONOMY_CONCEPT, 'tool_lp'),
                self::TAXONOMY_DOMAIN => new lang_string('taxonomy_' . self::TAXONOMY_DOMAIN, 'tool_lp'),
                self::TAXONOMY_INDICATOR => new lang_string('taxonomy_' . self::TAXONOMY_INDICATOR, 'tool_lp'),
                self::TAXONOMY_LEVEL => new lang_string('taxonomy_' . self::TAXONOMY_LEVEL, 'tool_lp'),
                self::TAXONOMY_OUTCOME => new lang_string('taxonomy_' . self::TAXONOMY_OUTCOME, 'tool_lp'),
                self::TAXONOMY_PRACTICE => new lang_string('taxonomy_' . self::TAXONOMY_PRACTICE, 'tool_lp'),
                self::TAXONOMY_PROFICIENCY => new lang_string('taxonomy_' . self::TAXONOMY_PROFICIENCY, 'tool_lp'),
                self::TAXONOMY_SKILL => new lang_string('taxonomy_' . self::TAXONOMY_SKILL, 'tool_lp'),
                self::TAXONOMY_VALUE => new lang_string('taxonomy_' . self::TAXONOMY_VALUE, 'tool_lp'),
            );
        }

        return $list;
    }

}