lib/ajax/blocks.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Provide interface for blocks AJAX actions
  19  *
  20  * @copyright  2011 Lancaster University Network Services Limited
  21  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  22  * @package core
  23  */
  24
  25 define('AJAX_SCRIPT', true);
  26 require_once(__DIR__ . '/../../config.php');
  27
  28 // Initialise ALL common incoming parameters here, up front.
  29 $pagehash = required_param('pagehash', PARAM_RAW);
  30 $action = optional_param('action', '', PARAM_ALPHA);
  31 // Params for blocks-move actions.
  32 $buimoveid = optional_param('bui_moveid', 0, PARAM_INT);
  33 $buinewregion = optional_param('bui_newregion', '', PARAM_ALPHAEXT);
  34 $buibeforeid = optional_param('bui_beforeid', 0, PARAM_INT);
  35
  36 $PAGE->set_url('/lib/ajax/blocks.php', ['pagehash' => $pagehash]);
  37
  38 // Retrieve the edited page from the session hash.
  39 $page = moodle_page::retrieve_edited_page($pagehash, MUST_EXIST);
  40
  41 // Verifying login and session.
  42 $cm = null;
  43 if (!is_null($page->cm)) {
  44     $cm = get_coursemodule_from_id(null, $page->cm->id, $page->course->id, false, MUST_EXIST);
  45 }
  46 require_login($page->course, false, $cm);
  47 require_sesskey();
  48 $PAGE->set_context($page->context);
  49
  50 if (!$page->user_can_edit_blocks() || !$page->user_is_editing()) {
  51     throw new moodle_exception('nopermissions', '', $page->url->out(), get_string('editblock'));
  52 }
  53
  54 // Send headers.
  55 echo $OUTPUT->header();
  56
  57 switch ($action) {
  58     case 'move':
  59         // Loading blocks and instances for the region.
  60         $page->blocks->load_blocks();
  61         $instances = $page->blocks->get_blocks_for_region($buinewregion);
  62
  63         $buinewweight = null;
  64         if ($buibeforeid == 0) {
  65             if (count($instances) === 0) {
  66                 // Moving the block into an empty region. Give it the default weight.
  67                 $buinewweight = 0;
  68             } else {
  69                 // Moving to very bottom.
  70                 $last = end($instances);
  71                 $buinewweight = $last->instance->weight + 1;
  72             }
  73         } else {
  74             // Moving somewhere.
  75             $lastweight = 0;
  76             $lastblock = 0;
  77             $first = reset($instances);
  78             if ($first) {
  79                 $lastweight = $first->instance->weight - 2;
  80             }
  81
  82             foreach ($instances as $instance) {
  83                 if ($instance->instance->id == $buibeforeid) {
  84                     // Location found, just calculate weight like in block_manager->create_block_contents() and quit the loop.
  85                     if ($lastblock == $buimoveid) {
  86                         // Same block, same place - nothing to move.
  87                         break;
  88                     }
  89                     $buinewweight = ($lastweight + $instance->instance->weight) / 2;
  90                     break;
  91                 }
  92                 $lastweight = $instance->instance->weight;
  93                 $lastblock = $instance->instance->id;
  94             }
  95         }
  96
  97         // Move block if we need.
  98         if (isset($buinewweight)) {
  99             // Nasty hack.
 100             $_POST['bui_newweight'] = $buinewweight;
 101             $page->blocks->process_url_move();
 102         }
 103         break;
 104 }