Made assertion messages visible in error messages and added example

Author: SengerM

OMPython/ModelicaSystem.py

@@ -250,7 +250,7 @@ def run(self) -> int:
         except subprocess.TimeoutExpired as ex:
             raise ModelicaSystemError(f"Timeout running command {repr(cmdl)}") from ex
         except subprocess.CalledProcessError as ex:
-            raise ModelicaSystemError(f"Error running command {repr(cmdl)}") from ex
+            raise ModelicaSystemError(f"Error running command {repr(cmdl)}\n{ex.stdout}") from ex
 
         return returncode
 

examples/parameters_validation/main.py

@@ -0,0 +1,42 @@
+from OMPython import ModelicaSystem
+from pathlib import Path
+
+def main(file=None):
+	"""Run a simple parameters validation model."""
+	model = ModelicaSystem(
+		str(Path(__file__).parent/'model.mo'), # Path to file where modelica code is.
+		'ParametersValidation', # Name of model from that file.
+	)
+	# Run the model with different parameters values and print the results:
+	for positive_number in [-1,1,.1]:
+		for negative_number in [-1,1,-.1]:
+			model.setParameters(
+				[
+					f'positive_number={positive_number}',
+					f'negative_number={negative_number}',
+				],
+			)
+			print('--------------------------------------', file=file)
+			print('Simulating with:', file=file)
+			print(f'\tpositive_number = {positive_number}', file=file)
+			print(f'\tnegative_number = {negative_number}', file=file)
+			try:
+				model.simulate() # Parameters values are validated here.
+			except Exception as e:
+				print(e, file=file)
+
+def test_passing()->bool:
+	"""Function to use for automatic testing. If returns `True` it means this example is working."""
+	class PrintSilencer:
+		def write(s:str):
+			pass
+	test_passing = False
+	try:
+		main(file=PrintSilencer())
+		test_passing = True
+	except Exception as e:
+		test_passing = False
+	return test_passing
+
+if __name__ == '__main__':
+	main()

examples/parameters_validation/model.mo

@@ -0,0 +1,10 @@
+model ParametersValidation "A dummy model to show how to validate parameters"
+	parameter Real positive_number = 1;
+	parameter Real negative_number = -1;
+
+	initial algorithm
+		assert(positive_number>0, "`positive_number` must be > 0");
+		assert(negative_number<0, "`negative_number` must be < 0");
+		assert(positive_number-negative_number > 1, "`positive_number - negative_number` must be > 1");
+
+end ParametersValidation;