MDL-65492 cache admin: make it easier to purge a cache repeatedly

This can be a big time-saver, e.g. during development.

cache/admin.php

@@ -208,8 +208,8 @@ if (!empty($action) && confirm_sesskey()) {
             break;
 
         case 'purgedefinition': // Purge a specific definition.
-            $definition = required_param('definition', PARAM_SAFEPATH);
-            list($component, $area) = explode('/', $definition, 2);
+            $id = required_param('definition', PARAM_SAFEPATH);
+            list($component, $area) = explode('/', $id, 2);
             $factory = cache_factory::instance();
             $definition = $factory->create_definition($component, $area);
             if ($definition->has_required_identifiers()) {
@@ -219,14 +219,27 @@ if (!empty($action) && confirm_sesskey()) {
                 // Alrighty we can purge just the data belonging to this definition.
                 cache_helper::purge_by_definition($component, $area);
             }
-            redirect($PAGE->url, get_string('purgedefinitionsuccess', 'cache'), 5);
+
+            $message = get_string('purgexdefinitionsuccess', 'cache', [
+                        'name' => $definition->get_name(),
+                        'component' => $component,
+                        'area' => $area,
+                    ]);
+            $purgeagainlink = html_writer::link(new moodle_url('/cache/admin.php', [
+                    'action' => 'purgedefinition', 'sesskey' => sesskey(), 'definition' => $id]),
+                    get_string('purgeagain', 'cache'));
+            redirect($PAGE->url, $message . ' ' . $purgeagainlink, 5);
             break;
 
         case 'purgestore':
         case 'purge': // Purge a store cache.
             $store = required_param('store', PARAM_TEXT);
             cache_helper::purge_store($store);
-            redirect($PAGE->url, get_string('purgestoresuccess', 'cache'), 5);
+            $message = get_string('purgexstoresuccess', 'cache', ['store' => $store]);
+            $purgeagainlink = html_writer::link(new moodle_url('/cache/admin.php', [
+                    'action' => 'purgestore', 'sesskey' => sesskey(), 'store' => $store]),
+                    get_string('purgeagain', 'cache'));
+            redirect($PAGE->url, $message . ' ' . $purgeagainlink, 5);
             break;
 
         case 'newlockinstance':

lang/en/cache.php

@@ -141,8 +141,9 @@ $string['plugin'] = 'Plugin';
 $string['pluginsummaries'] = 'Installed cache stores';
 $string['privacy:metadata:cachestore'] = 'The Cache subsystem stores data temporarily on behalf of other parts of Moodle. This data is not easily identifiable, and is very short lived. It serves as a cache of data stored elsewhere in Moodle, and should therefore already be handled by those Moodle components.';
 $string['purge'] = 'Purge';
-$string['purgedefinitionsuccess'] = 'Successfully purged the requested definition.';
-$string['purgestoresuccess'] = 'Successfully purged the requested store.';
+$string['purgeagain'] = 'Purge again';
+$string['purgexdefinitionsuccess'] = 'Successfully purged the "{$a->name}" cache ({$a->component}/{$a->area}).';
+$string['purgexstoresuccess'] = 'Successfully purged the "{$a->store}" store.';
 $string['requestcount'] = 'Test with {$a} requests';
 $string['rescandefinitions'] = 'Rescan definitions';
 $string['result'] = 'Result';
@@ -190,3 +191,7 @@ $string['unsupportedmode'] = 'Unsupported mode';
 $string['untestable'] = 'Untestable';
 $string['userinputsharingkey'] = 'Custom key for sharing';
 $string['userinputsharingkey_help'] = 'Enter your own private key here. When you set up other stores on other sites you wish to share data with make sure you set the exact same key there.';
+
+// Deprecated since Moodle 3.8.
+$string['purgedefinitionsuccess'] = 'Successfully purged the requested definition.';
+$string['purgestoresuccess'] = 'Successfully purged the requested store.';

lang/en/deprecated.txt

@@ -158,3 +158,5 @@ backpackbadges,core_badges
 nobackpackbadges,core_badges
 nobackpackcollections,core_badges
 error:nogroups,core_badges
+purgedefinitionsuccess,core_cache
+purgestoresuccess,core_cache