conversion_rules.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/>.

namespace qtype_formulas;

/* Each entry of $basicunitconversionrule is a pair:
 *  - The first string is the name of the rule, which is used when editing the form
 *  - The second string is the actual rule that will be parsed and used as unit conversion
 *  - The array index is the unique id for the rule, which will be stored in the database
 * Note: the id from 0 to 99 are reserved, please do not use to create you own rules
 */
class unit_conversion_rules {
    private $basicunitconversionrule = array();

    // Initialize the internal conversion rule.
    public function __construct() {
        $this->basicunitconversionrule[0] = array(get_string('none', 'qtype_formulas'), '');
        $this->basicunitconversionrule[1] = array(get_string('commonsiunit', 'qtype_formulas'), '
m: k c d m u n p f;
s: m u n p f;
g: k m u n p f;
mol: m u n p;
N: M k m u n p f;
A: m u n p f;
J: k M G T P m u n p f;
J = 6.24150947e+18 eV;
eV: k M G T P m u;
W: k M G T P m u n p f;
Pa: k M G T P;
Hz: k M G T P E;
C: k m u n p f;
V: k M G m u n p f;
ohm: m k M G T P;
F: m u n p f;
T: k m u n p;
H: k m u n p;
');

        /* You can define your own rules here, for instance:
         * $this->basicunitconversionrule[100] = array(
         * $this->basicunitconversionrule[1][0] + ' and your own conversion rules',
         * $this->basicunitconversionrule[1][1] + '');
         */

    }

    public function entry($n) {
        return $this->basicunitconversionrule[$n];
    }

    public function allrules() {
        return $this->basicunitconversionrule;
    }
}