/**
* Preloads the list of active filters for all activities (modules) on the course
* using two database queries.
*
* @param course_modinfo $modinfo Course object from get_fast_modinfo
*/
function filter_preload_activities(course_modinfo $modinfo)
{
global $DB, $FILTERLIB_PRIVATE;
if (!isset($FILTERLIB_PRIVATE)) {
$FILTERLIB_PRIVATE = new stdClass();
}
// Don't repeat preload
if (!isset($FILTERLIB_PRIVATE->preloaded)) {
$FILTERLIB_PRIVATE->preloaded = array();
}
if (!empty($FILTERLIB_PRIVATE->preloaded[$modinfo->get_course_id()])) {
return;
}
$FILTERLIB_PRIVATE->preloaded[$modinfo->get_course_id()] = true;
// Get contexts for all CMs
$cmcontexts = array();
$cmcontextids = array();
foreach ($modinfo->get_cms() as $cm) {
$modulecontext = context_module::instance($cm->id);
$cmcontextids[] = $modulecontext->id;
$cmcontexts[] = $modulecontext;
}
// Get course context and all other parents...
$coursecontext = context_course::instance($modinfo->get_course_id());
$parentcontextids = explode('/', substr($coursecontext->path, 1));
$allcontextids = array_merge($cmcontextids, $parentcontextids);
// Get all filter_active rows relating to all these contexts
list($sql, $params) = $DB->get_in_or_equal($allcontextids);
$filteractives = $DB->get_records_select('filter_active', "contextid {$sql}", $params);
// Get all filter_config only for the cm contexts
list($sql, $params) = $DB->get_in_or_equal($cmcontextids);
$filterconfigs = $DB->get_records_select('filter_config', "contextid {$sql}", $params);
// Note: I was a bit surprised that filter_config only works for the
// most specific context (i.e. it does not need to be checked for course
// context if we only care about CMs) however basede on code in
// filter_get_active_in_context, this does seem to be correct.
// Build course default active list. Initially this will be an array of
// filter name => active score (where an active score >0 means it's active)
$courseactive = array();
// Also build list of filter_active rows below course level, by contextid
$remainingactives = array();
// Array lists filters that are banned at top level
$banned = array();
// Add any active filters in parent contexts to the array
foreach ($filteractives as $row) {
$depth = array_search($row->contextid, $parentcontextids);
if ($depth !== false) {
// Find entry
if (!array_key_exists($row->filter, $courseactive)) {
$courseactive[$row->filter] = 0;
}
// This maths copes with reading rows in any order. Turning on/off
// at site level counts 1, at next level down 4, at next level 9,
// then 16, etc. This means the deepest level always wins, except
// against the -9999 at top level.
$courseactive[$row->filter] += ($depth + 1) * ($depth + 1) * $row->active;
if ($row->active == TEXTFILTER_DISABLED) {
$banned[$row->filter] = true;
}
} else {
// Build list of other rows indexed by contextid
if (!array_key_exists($row->contextid, $remainingactives)) {
$remainingactives[$row->contextid] = array();
}
$remainingactives[$row->contextid][] = $row;
}
}
// Chuck away the ones that aren't active.
foreach ($courseactive as $filter => $score) {
if ($score <= 0) {
unset($courseactive[$filter]);
} else {
$courseactive[$filter] = array();
}
}
// Loop through the contexts to reconstruct filter_active lists for each
// cm on the course.
if (!isset($FILTERLIB_PRIVATE->active)) {
$FILTERLIB_PRIVATE->active = array();
}
foreach ($cmcontextids as $contextid) {
// Copy course list
$FILTERLIB_PRIVATE->active[$contextid] = $courseactive;
// Are there any changes to the active list?
if (array_key_exists($contextid, $remainingactives)) {
foreach ($remainingactives[$contextid] as $row) {
if ($row->active > 0 && empty($banned[$row->filter])) {
// If it's marked active for specific context, add entry
// (doesn't matter if one exists already).
$FILTERLIB_PRIVATE->active[$contextid][$row->filter] = array();
} else {
// If it's marked inactive, remove entry (doesn't matter
// if it doesn't exist).
unset($FILTERLIB_PRIVATE->active[$contextid][$row->filter]);
}
}
}
}
// Process all config rows to add config data to these entries.
foreach ($filterconfigs as $row) {
if (isset($FILTERLIB_PRIVATE->active[$row->contextid][$row->filter])) {
$FILTERLIB_PRIVATE->active[$row->contextid][$row->filter][$row->name] = $row->value;
}
}
}
/**
* Returns course ID - from course_sections table
*
* @return int
*/
private function get_course() {
return $this->modinfo->get_course_id();
}
