lib/ajax/getnavbranch.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * This file is used to deliver a branch from the navigation structure
  20  * in XML format back to a page from an AJAX call
  21  *
  22  * @since Moodle 2.0
  23  * @package core
  24  * @copyright 2009 Sam Hemelryk
  25  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 define('AJAX_SCRIPT', true);
  29
  30 /** Include config */
  31 require_once(__DIR__ . '/../../config.php');
  32 /** Include course lib for its functions */
  33 require_once($CFG->dirroot.'/course/lib.php');
  34
  35 if (!empty($CFG->forcelogin)) {
  36     require_login();
  37 }
  38
  39 try {
  40     // Start buffer capture so that we can `remove` any errors
  41     ob_start();
  42     // Require id This is the key for whatever branch we want to get.
  43     // This accepts alphanum because the courses and my courses branches don't have numerical keys.
  44     // For those branches we return the alphanum key, courses and mycourses.
  45     $branchid = required_param('id', PARAM_ALPHANUM);
  46     // This identifies the type of the branch we want to get
  47     $branchtype = required_param('type', PARAM_INT);
  48     // This identifies the block instance requesting AJAX extension
  49     $instanceid = optional_param('instance', null, PARAM_INT);
  50
  51     $PAGE->set_context(context_system::instance());
  52
  53     // Create a global nav object
  54     $navigation = new global_navigation_for_ajax($PAGE, $branchtype, $branchid);
  55
  56     $linkcategories = false;
  57
  58     if ($instanceid!==null) {
  59         // Get the db record for the block instance
  60         $blockrecord = $DB->get_record('block_instances', array('id'=>$instanceid,'blockname'=>'navigation'));
  61         if ($blockrecord!=false) {
  62
  63             // Instantiate a block_instance object so we can access config
  64             $block = block_instance('navigation', $blockrecord);
  65
  66             $trimmode = block_navigation::TRIM_RIGHT;
  67             $trimlength = 50;
  68
  69             // Set the trim mode
  70             if (!empty($block->config->trimmode)) {
  71                 $trimmode = (int)$block->config->trimmode;
  72             }
  73             // Set the trim length
  74             if (!empty($block->config->trimlength)) {
  75                 $trimlength = (int)$block->config->trimlength;
  76             }
  77             if (!empty($block->config->linkcategories) && $block->config->linkcategories == 'yes') {
  78                 $linkcategories = true;
  79             }
  80         }
  81     }
  82
  83     // Create a navigation object to use, we can't guarantee PAGE will be complete
  84     if (!isloggedin()) {
  85         $navigation->set_expansion_limit(navigation_node::TYPE_COURSE);
  86     } else {
  87         if (isset($block) && !empty($block->config->expansionlimit)) {
  88             $navigation->set_expansion_limit($block->config->expansionlimit);
  89         }
  90     }
  91     if (isset($block)) {
  92         $block->trim($navigation, $trimmode, $trimlength, ceil($trimlength/2));
  93     }
  94     $converter = new navigation_json();
  95
  96     // Find the actual branch we are looking for
  97     if ($branchtype != 0) {
  98         $branch = $navigation->find($branchid, $branchtype);
  99     } else if ($branchid === 'mycourses' || $branchid === 'courses') {
 100         $branch = $navigation->find($branchid, navigation_node::TYPE_ROOTNODE);
 101     } else {
 102         throw new coding_exception('Invalid branch type/id passed to AJAX call to load branches.');
 103     }
 104
 105     // Remove links to categories if required.
 106     if (!$linkcategories) {
 107         foreach ($branch->find_all_of_type(navigation_node::TYPE_CATEGORY) as $category) {
 108             $category->action = null;
 109         }
 110         foreach ($branch->find_all_of_type(navigation_node::TYPE_MY_CATEGORY) as $category) {
 111             $category->action = null;
 112         }
 113     }
 114
 115     // Stop buffering errors at this point
 116     $html = ob_get_contents();
 117     ob_end_clean();
 118 } catch (Exception $e) {
 119     throw new coding_exception('Error: '.$e->getMessage());
 120 }
 121
 122 // Check if the buffer contianed anything if it did ERROR!
 123 if (trim($html) !== '') {
 124     throw new coding_exception('Errors were encountered while producing the navigation branch'."\n\n\n".$html);
 125 }
 126 // Check that branch isn't empty... if it is ERROR!
 127 if (empty($branch) || ($branch->nodetype !== navigation_node::NODETYPE_BRANCH && !$branch->isexpandable)) {
 128     throw new coding_exception('No further information available for this branch');
 129 }
 130
 131 // Prepare an XML converter for the branch
 132 $converter->set_expandable($navigation->get_expandable());
 133 // Set XML headers
 134 header('Content-type: text/plain; charset=utf-8');
 135 // Convert and output the branch as XML
 136 echo $converter->convert($branch);