function definition()
{
global $CFG;
$mform =& $this->_form;
$category = $this->_customdata;
ensure_context_subobj_present($category, CONTEXT_COURSECAT);
$this->_category = $category;
/// Check permissions, to see if it OK to give the option to delete
/// the contents, rather than move elsewhere.
/// Are there any subcategories of this one, can they be deleted?
$candeletecontent = true;
$tocheck = get_child_categories($category->id);
$containscategories = !empty($tocheck);
$categoryids = array($category->id);
while (!empty($tocheck)) {
$checkcat = array_pop($tocheck);
$childcategoryids[] = $checkcat->id;
$tocheck = $tocheck + get_child_categories($checkcat->id);
if ($candeletecontent && !has_capability('moodle/category:manage', $checkcat->context)) {
$candeletecontent = false;
}
}
/// Are there any courses in here, can they be deleted?
$containedcourses = get_records_sql("\n SELECT id,1 FROM {$CFG->prefix}course c\n WHERE c.category IN (" . implode(',', $categoryids) . ")");
$containscourses = false;
if ($containedcourses) {
$containscourses = true;
foreach ($containedcourses as $courseid => $notused) {
if ($candeletecontent && !can_delete_course($courseid)) {
$candeletecontent = false;
break;
}
}
}
/// Are there any questions in the question bank here?
$containsquestions = question_context_has_any_questions($category->context);
/// Get the list of categories we might be able to move to.
$testcaps = array();
if ($containscourses) {
$testcaps[] = 'moodle/course:create';
}
if ($containscategories || $containsquestions) {
$testcaps[] = 'moodle/category:manage';
}
$displaylist = array();
$notused = array();
if (!empty($testcaps)) {
make_categories_list($displaylist, $notused, $testcaps, $category->id);
}
/// Now build the options.
$options = array();
if ($displaylist) {
$options[0] = get_string('movecontentstoanothercategory');
}
if ($candeletecontent) {
$options[1] = get_string('deleteallcannotundo');
}
/// Now build the form.
$mform->addElement('header', 'general', get_string('categorycurrentcontents', '', format_string($category->name)));
if ($containscourses || $containscategories || $containsquestions) {
if (empty($options)) {
print_error('youcannotdeletecategory', 'error', 'index.php', format_string($category->name));
}
/// Describe the contents of this category.
$contents = '<ul>';
if ($containscategories) {
$contents .= '<li>' . get_string('subcategories') . '</li>';
}
if ($containscourses) {
$contents .= '<li>' . get_string('courses') . '</li>';
}
if ($containsquestions) {
$contents .= '<li>' . get_string('questionsinthequestionbank') . '</li>';
}
$contents .= '</ul>';
$mform->addElement('static', 'emptymessage', get_string('thiscategorycontains'), $contents);
/// Give the options for what to do.
$mform->addElement('select', 'fulldelete', get_string('whattodo'), $options);
if (count($options) == 1) {
$mform->hardFreeze('fulldelete');
$mform->setConstant('fulldelete', reset(array_keys($options)));
}
if ($displaylist) {
$mform->addElement('select', 'newparent', get_string('movecategorycontentto'), $displaylist);
if (in_array($category->parent, $displaylist)) {
$mform->setDefault('newparent', $category->parent);
}
$mform->disabledIf('newparent', 'fulldelete', 'eq', '1');
}
} else {
$mform->addElement('hidden', 'fulldelete', 1);
$mform->setType('fulldelete', PARAM_INT);
$mform->addElement('static', 'emptymessage', '', get_string('deletecategoryempty'));
}
$mform->addElement('hidden', 'delete');
$mform->setType('delete', PARAM_ALPHANUM);
$mform->addElement('hidden', 'sure');
$mform->setType('sure', PARAM_ALPHANUM);
$mform->setDefault('sure', md5(serialize($category)));
//--------------------------------------------------------------------------------
$this->add_action_buttons(true, get_string('delete'));
}
/**
* This function recursively travels the categories, building up a nice list
* for display. It also makes an array that list all the parents for each
* category.
*
* For example, if you have a tree of categories like:
* Miscellaneous (id = 1)
* Subcategory (id = 2)
* Sub-subcategory (id = 4)
* Other category (id = 3)
* Then after calling this function you will have
* $list = array(1 => 'Miscellaneous', 2 => 'Miscellaneous / Subcategory',
* 4 => 'Miscellaneous / Subcategory / Sub-subcategory',
* 3 => 'Other category');
* $parents = array(2 => array(1), 4 => array(1, 2));
*
* If you specify $requiredcapability, then only categories where the current
* user has that capability will be added to $list, although all categories
* will still be added to $parents, and if you only have $requiredcapability
* in a child category, not the parent, then the child catgegory will still be
* included.
*
* If you specify the option $excluded, then that category, and all its children,
* are omitted from the tree. This is useful when you are doing something like
* moving categories, where you do not want to allow people to move a category
* to be the child of itself.
*
* @param array $list For output, accumulates an array categoryid => full category path name
* @param array $parents For output, accumulates an array categoryid => list of parent category ids.
* @param string/array $requiredcapability if given, only categories where the current
* user has this capability will be added to $list. Can also be an array of capabilities,
* in which case they are all required.
* @param integer $excludeid Omit this category and its children from the lists built.
* @param object $category Build the tree starting at this category - otherwise starts at the top level.
* @param string $path For internal use, as part of recursive calls.
*/
function make_categories_list(&$list, &$parents, $requiredcapability = '', $excludeid = 0, $category = NULL, $path = "")
{
// initialize the arrays if needed
if (!is_array($list)) {
$list = array();
}
if (!is_array($parents)) {
$parents = array();
}
if (empty($category)) {
// Start at the top level.
$category = new stdClass();
$category->id = 0;
} else {
// This is the excluded category, don't include it.
if ($excludeid > 0 && $excludeid == $category->id) {
return;
}
// Update $path.
if ($path) {
$path = $path . ' / ' . format_string($category->name);
} else {
$path = format_string($category->name);
}
// Add this category to $list, if the permissions check out.
if (empty($requiredcapability)) {
$list[$category->id] = $path;
} else {
ensure_context_subobj_present($category, CONTEXT_COURSECAT);
$requiredcapability = (array) $requiredcapability;
if (has_all_capabilities($requiredcapability, $category->context)) {
$list[$category->id] = $path;
}
}
}
// Add all the children recursively, while updating the parents array.
if ($categories = get_child_categories($category->id)) {
foreach ($categories as $cat) {
if (!empty($category->id)) {
if (isset($parents[$category->id])) {
$parents[$cat->id] = $parents[$category->id];
}
$parents[$cat->id][] = $category->id;
}
make_categories_list($list, $parents, $requiredcapability, $excludeid, $cat, $path);
}
}
}
