MDL-44357 theme: Allow core to compile LESS in PHP

lib/classes/lessc.php

@@ -0,0 +1,99 @@
+<?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/>.
+
+/**
+ * Moodle implementation of LESS.
+ *
+ * @package    core
+ * @copyright  2014 Frédéric Massart
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+require_once($CFG->libdir . '/lessphp/Autoloader.php');
+Less_Autoloader::register();
+
+/**
+ * Moodle LESS compiler class.
+ *
+ * @package    core
+ * @copyright  2014 Frédéric Massart
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class core_lessc extends Less_Parser {
+
+    /**
+     * Add a rule to import a file.
+     *
+     * This is useful when you want to import the content of a LESS files but
+     * you are not sure if it contains @imports or not. This method will
+     * import the file using @import with a relative path from your
+     * main file to compile. Less does not support absolute paths.
+     *
+     * @param string $filepath The path to the LESS file to import.
+     * @param string $relativeto The path from which the relative path should be built.
+     *                           Typically this would be the path to a file passed
+     *                           to {@link self::parseFile()}.
+     * @return void
+     */
+    public function import_file($filepath, $relativeto) {
+        global $CFG;
+
+        if (!is_readable($filepath) || !is_readable($relativeto)) {
+            throw new coding_exception('Could not read the files');
+        }
+
+        $filepath = realpath($filepath);
+        $relativeto = realpath($relativeto);
+
+        if (strtolower(substr($filepath, -5)) != '.less') {
+            throw new coding_exception('Imports only work with LESS files.');
+        } else if (strpos(realpath($filepath), $CFG->dirroot) !== 0 ||
+                strpos(realpath($relativeto), $CFG->dirroot) !== 0) {
+            throw new coding_exception('Files must be in CFG->dirroot.');
+        }
+
+        // Simplify the file path the start of dirroot.
+        $filepath = trim(substr($filepath, strlen($CFG->dirroot)), '/');
+        $relativeto = trim(substr($relativeto, strlen($CFG->dirroot)), '/');
+
+        // Split the file path and remove the file name.
+        $dirs = explode('/', $relativeto);
+        array_pop($dirs);
+
+        // Generate the relative path.
+        $relativepath = str_repeat('../', count($dirs)) . $filepath;
+
+        $this->parse('@import "' . $relativepath . '";');
+    }
+
+    /**
+     * Parse the content of a file.
+     *
+     * The purpose of this method is to provide a way to import the
+     * content of a file without messing with the import directories
+     * as {@link self::parseFile()} would do. But of course you should
+     * have manually set your import directories previously.
+     *
+     * @see self::SetImportDirs()
+     * @param string $filepath The path to the file.
+     * @return void
+     */
+    public function parse_file_content($filepath) {
+        $this->parse(file_get_contents($filepath));
+    }
+
+}