#606 - handle user running invalid Python code (#608)

see #606 for more details. with this commit, when invalid Python code is called by user, TagUI continues operation and the error message is stored in py_result. before this change, TagUI hangs as the Python process does not return response.

src/tagui

@@ -6,7 +6,7 @@ chrome_command="google-chrome"
 
 if [ -z "$1" ]
 then
-echo "tagui v5.9: use following options and this syntax to run - ./tagui flow_filename option(s)"
+echo "tagui v5.10: use following options and this syntax to run - ./tagui flow_filename option(s)"
 echo
 echo "chrome   - run on visible Chrome web browser instead of invisible PhantomJS (first install Chrome)"
 echo "headless - run on invisible Chrome web browser instead of default PhantomJS (first install Chrome)"

src/tagui.cmd

@@ -8,7 +8,7 @@ rem enable windows for loop advanced flow control
 setlocal enableextensions enabledelayedexpansion
 
 if "%~1"=="" (
-echo tagui v5.9: use following options and this syntax to run - tagui flow_filename option^(s^)
+echo tagui v5.10: use following options and this syntax to run - tagui flow_filename option^(s^)
 echo.
 echo chrome   - run on visible Chrome web browser instead of invisible PhantomJS ^(first install Chrome^)
 echo headless - run on invisible Chrome web browser instead of default PhantomJS ^(first install Chrome^)

src/tagui_py/tagui_py.py

@@ -46,10 +46,15 @@ def py_intent ( raw_intent ):
 	except NameError:
 		temp_output = sys.stdout = sys.stderr = io.StringIO()
 
-	exec(params,globals())
+	# try/except for user sending invalid Python code
+	try:
+		exec(params,globals())
+		temp_result = temp_output.getvalue().strip()
+	except Exception as e:
+		temp_result = str(e)
+
 	sys.stdout = old_stdout
 	sys.stderr = old_stderr
-	temp_result = temp_output.getvalue().strip()
 
 	if temp_result != '':
 		print(temp_result)