test if directory exist before trying to delete its content to avoid

errors

ui/nG6/lib/class.tx_nG6_utils.php

@@ -137,7 +137,6 @@ class tx_nG6_utils {
     static function purge_directory($user_login, $user_pwd, $directory) {
         if ($directory != 'undefined' && $directory != '') {
     		// And process the directories structure, remove all files except .html ans .png
-
      		$connection = ssh2_connect('127.0.0.1', 22);
     		if (!$connection) {
     			return 3;
@@ -146,6 +145,20 @@ class tx_nG6_utils {
     		if (!ssh2_auth_password($connection, $user_login,$user_pwd )){
     			return 2;
     		}
+    		$stream = ssh2_exec($connection, 'ls '.$directory.'/*' );
+    		$errorStream = ssh2_fetch_stream($stream, SSH2_STREAM_STDERR);
+    		// Enable blocking for both streams
+    		stream_set_blocking($errorStream, true);
+    		stream_set_blocking($stream, true);
+    			
+    		//if error is raised, $directory does not exist>no problem (in case of an analysis which do not have associated files 
+    		
+    		if(stream_get_contents($errorStream)) {
+    			// Close the streams
+    			fclose($errorStream);
+    			fclose($stream);
+    			return 0;
+    		}
     		
     		$stream = ssh2_exec($connection, 'ls '.$directory.'/*  | grep -v -e ".html$" -e ".png$" | xargs rm -f' );
     		$errorStream = ssh2_fetch_stream($stream, SSH2_STREAM_STDERR);
@@ -153,8 +166,7 @@ class tx_nG6_utils {
     		stream_set_blocking($errorStream, true);
     		stream_set_blocking($stream, true);
     				 
-    		// Whichever of the two below commands is listed first will receive its appropriate output.  The second command receives nothing
-  				    
+    		//if error is raised, connected user does not have the right to delete the files
     		if(stream_get_contents($errorStream)) {
     			// Close the streams
     			fclose($errorStream);