Implement InstallationFailed exception

application/MantisBT/Exception/Plugin/InstallationFailed.php

@@ -0,0 +1,18 @@
+<?php
+namespace MantisBT\Exception\Plugin;
+use MantisBT\Exception\ExceptionAbstract;
+
+require_api('lang_api.php');
+
+/* TODO: This class is currently too vague. Plugins should throw more detailed
+ * exceptions. Perhaps this class can be abstracted so that it can be extended
+ * by plugins, but handled by MantisBT core in consistent ways.
+ */
+class InstallationFailed extends ExceptionAbstract {
+	public function __construct($pluginName, $failureReason) {
+		$errorMessage = lang_get(ERROR_PLUGIN_INSTALL_FAILED, null, false);
+		$errorMessage = sprintf($errorMessage, $pluginName, $failureReason);
+		parent::__construct(ERROR_PLUGIN_INSTALL_FAILED, $errorMessage, null);
+		$this->responseCode = 500;
+	}
+}

public/plugins/XmlImportExport/XmlImportExport.php

@@ -23,6 +23,8 @@
  * @link http://www.mantisbt.org
  */
 
+use MantisBT\Exception\Plugin\InstallationFailed;
+
 /**
  * XmlImportExportPlugin Class
  */
@@ -68,9 +70,7 @@ function export_issues_menu( ) {
 	function install() {
 		$result = extension_loaded("xmlreader") && extension_loaded("xmlwriter");
 		if ( ! $result ) {
-			#\todo returning false should trigger some error reporting, needs rethinking error_api
-			error_parameters( plugin_lang_get( 'error_no_xml' ) );
-			trigger_error( ERROR_PLUGIN_INSTALL_FAILED, ERROR );
+			throw new InstallationFailed( plugin_lang_get( 'title' ), plugin_lang_get( 'error_no_xml' ) );
 		}
 		return $result;
 	}