Avoid checking for plugin updates in each page refresh

qa-content/qa-admin.js

@@ -148,6 +148,13 @@ function qa_version_check(uri, version, elem, isCore)
 	);
 }
 
+function qa_version_check_array(versionChecks)
+{
+	for (var i = 0; i < versionChecks.length; i++) {
+		qa_version_check(versionChecks[i].uri, versionChecks[i].version, versionChecks[i].elem, false)
+	}
+}
+
 function qa_get_enabled_plugins_hashes()
 {
 	var hashes = [];

qa-include/Q2A/Plugin/PluginManager.php

@@ -25,6 +25,8 @@ class Q2A_Plugin_PluginManager
 {
 	const PLUGIN_DELIMITER = ';';
 	const OPT_ENABLED_PLUGINS = 'enabled_plugins';
+	const OPT_LAST_UPDATE_CHECK = 'last_plugin_update_check';
+	const NUMBER_OF_DAYS_TO_CHECK_FOR_UPDATE = 14;
 
 	private $loadBeforeDbInit = array();
 	private $loadAfterDbInit = array();
@@ -180,4 +182,27 @@ class Q2A_Plugin_PluginManager
 
 		$this->setEnabledPluginsOption($finalEnabledPlugins);
 	}
+
+	/**
+	 * @return bool
+	 */
+	public function shouldCheckForUpdate()
+	{
+		$lastUpdateCheck = (int)qa_opt(self::OPT_LAST_UPDATE_CHECK);
+		$currentTime = (int)qa_opt('db_time');
+
+		return $currentTime - $lastUpdateCheck > self::NUMBER_OF_DAYS_TO_CHECK_FOR_UPDATE * 24 * 60 * 60;
+	}
+
+	/**
+	 * @param int|null $time
+	 */
+	public function performUpdateCheck($time = null)
+	{
+		if ($time === null) {
+			$time = time();
+		}
+
+		qa_opt(self::OPT_LAST_UPDATE_CHECK, $time);
+	}
 }

qa-include/lang/qa-lang-admin.php

@@ -273,6 +273,7 @@ return array(
 	'users_registered' => 'Registered users:',
 	'users_title' => 'Users',
 	'users_voted' => 'Users who voted:',
+	'version_check' => 'Check for updates',
 	'version_get_x' => 'get ^',
 	'version_latest' => 'latest',
 	'version_latest_unknown' => 'latest unknown',

qa-include/pages/admin/admin-plugins.php

@@ -62,7 +62,9 @@ if (qa_is_http_post()) {
 			$enabledPluginHashesArray = explode(';', $enabledPluginHashes);
 			$pluginDirectories = array_keys(array_intersect($pluginHashes, $enabledPluginHashesArray));
 			$pluginManager->setEnabledPlugins($pluginDirectories);
-
+			qa_redirect('admin/plugins');
+		} else if (qa_clicked('doversioncheck')) {
+			$pluginManager->performUpdateCheck(0);
 			qa_redirect('admin/plugins');
 		}
 	}
@@ -138,6 +140,9 @@ if (!empty($fileSystemPlugins)) {
 
 	qa_sort_by($sortedPluginFiles, 'name');
 
+	$versionChecks = array();
+	$shouldCheckForUpdate = $pluginManager->shouldCheckForUpdate();
+
 	$pluginIndex = -1;
 	foreach ($sortedPluginFiles as $pluginDirectory => $metadata) {
 		$pluginIndex++;
@@ -168,14 +173,16 @@ if (!empty($fileSystemPlugins)) {
 		} else
 			$authorhtml = '';
 
-		if ($metaver && isset($metadata['update_uri']) && strlen($metadata['update_uri'])) {
+		if ($shouldCheckForUpdate && $metaver && isset($metadata['update_uri']) && strlen($metadata['update_uri'])) {
 			$elementid = 'version_check_' . md5($pluginDirectory);
 
-			$updatehtml = '(<span id="' . $elementid . '">...</span>)';
-
-			$qa_content['script_onloads'][] = array(
-				"qa_version_check(" . qa_js($metadata['update_uri']) . ", " . qa_js($metadata['version'], true) . ", " . qa_js($elementid) . ", false);"
+			$versionChecks[] = array(
+				'uri' => $metadata['update_uri'],
+				'version' => $metadata['version'],
+				'elem' => $elementid,
 			);
+
+			$updatehtml = '(<span id="' . $elementid . '">...</span>)';
 		}
 		else
 			$updatehtml = '';
@@ -246,6 +253,14 @@ if (!empty($fileSystemPlugins)) {
 			}
 		}
 	}
+
+	if ($shouldCheckForUpdate) {
+		$pluginManager->performUpdateCheck();
+
+		$qa_content['script_onloads'][] = array(
+			sprintf('qa_version_check_array(%s);', json_encode($versionChecks)),
+		);
+	}
 }
 
 $qa_content['navigation']['sub'] = qa_admin_sub_navigation();
@@ -260,6 +275,10 @@ $qa_content['form'] = array(
 			'tags' => 'name="dosave"',
 			'label' => qa_lang_html('admin/save_options_button'),
 		),
+		'doversioncheck' => array(
+			'tags' => 'name="doversioncheck"',
+			'label' => qa_lang_html('admin/version_check'),
+		),
 	),
 
 	'hidden' => array(