allow user plugins to expose public methods out in a limited fashion

classes/handler/public.php

@@ -1086,5 +1086,37 @@ class Handler_Public extends Handler {
 
 		return "tag:" . parse_url(get_self_url_prefix(), PHP_URL_HOST) . ",$timestamp:/$id";
 	}
+
+	// this should be used very carefully because this endpoint is exposed to unauthenticated users
+	// plugin data is not loaded because there's no user context and owner_uid/session may or may not be available
+	// in general, don't do anything user-related in here and do not modify $_SESSION
+	public function pluginhandler() {
+		$host = new PluginHost();
+
+		$plugin = basename($_REQUEST["plugin"]);
+		$method = $_REQUEST["pmethod"];
+
+		$host->load($plugin, PluginHost::KIND_USER, 0);
+		$host->load_data();
+
+		$pclass = $host->get_plugin($plugin);
+
+		if ($pclass) {
+			if (method_exists($pclass, $method)) {
+				if ($pclass->is_public_method($method)) {
+					$pclass->$method();
+				} else {
+					header("Content-Type: text/json");
+					print error_json(6);
+				}
+			} else {
+				header("Content-Type: text/json");
+				print error_json(13);
+			}
+		} else {
+			header("Content-Type: text/json");
+			print error_json(14);
+		}
+	}
 }
-?>
+?>

classes/plugin.php

@@ -22,6 +22,10 @@ class Plugin {
 		return array();
 	}
 
+	function is_public_method($method) {
+		return false;
+	}
+
 	function get_js() {
 		return "";
 	}

plugins/af_zz_imgproxy/init.php

@@ -8,6 +8,10 @@ class Af_Zz_ImgProxy extends Plugin {
 			"fox");
 	}
 
+	function is_public_method($method) {
+		return $method === "imgproxy";
+	}
+
 	function init($host) {
 		$this->host = $host;
 
@@ -27,6 +31,7 @@ class Af_Zz_ImgProxy extends Plugin {
 	}
 
 	public function imgproxy() {
+
 		$url = rewrite_relative_url(SELF_URL_PATH, $_REQUEST["url"]);
 		$kind = (int) $_REQUEST["kind"]; // 1 = video
 
@@ -48,9 +53,6 @@ class Af_Zz_ImgProxy extends Plugin {
 		} else {
 			$data = fetch_file_contents(array("url" => $url));
 
-			global $fetch_last_error;
-			print $fetch_last_error;
-
 			if ($data) {
 				if (file_put_contents($local_filename, $data)) {
 					$mimetype = mime_content_type($local_filename);
@@ -76,7 +78,7 @@ class Af_Zz_ImgProxy extends Plugin {
 
 		if (($scheme != 'https' && $scheme != "") || $is_remote) {
 			if (strpos($url, "data:") !== 0) {
-				$url = "backend.php?op=pluginhandler&plugin=af_zz_imgproxy&method=imgproxy&kind=$kind&url=" .
+				$url = "public.php?op=pluginhandler&plugin=af_zz_imgproxy&pmethod=imgproxy&kind=$kind&url=" .
 					urlencode($url);
 			}
 		}