Merge pull request #4 from ataitler/StructureBranch

handling missing pyRDDLGym dependency for viz import

rddl-repository/Main.py

@@ -6,9 +6,10 @@
 
 def main():
     manager = RDDLRepoManager(rebuild=True)
-    manager.ListProblems()
-    envInfo = manager.GetProblem('CooperativeRecon_ippc2018')
-    envInfo.list_instances()
+    # manager.ListProblems()
+    # envInfo = manager.GetProblem('CooperativeRecon_ippc2018')
+    envInfo = manager.GetProblem('RaceCar')
+    # envInfo.list_instances()
     envInfo.get_domain()
     envInfo.get_instance(0)
     envInfo.get_visualizer()

rddl-repository/Manager/ErrorHandling.py

@@ -8,4 +8,7 @@ class RDDLRepoDomainNotExist(ValueError):
     pass
 
 class RDDLRepoProblemDuplication(ValueError):
-    pass
+    pass
+
+class RDDLRepoUnresolvedDependency(ValueError):
+    pass

rddl-repository/Manager/ProblemInfo.py

@@ -1,8 +1,12 @@
 import os.path
 import sys
+import importlib.util
+
+from .ErrorHandling import RDDLRepoInstanceNotExist, RDDLRepoUnresolvedDependency
 
-from .ErrorHandling import RDDLRepoInstanceNotExist
 sys.path.append('../rddl-repository')
+viz_backend_package_name = 'pyRDDLGym'
+
 
 class ProblemInfo:
     def __init__(self, problem_data):
@@ -30,6 +34,11 @@ def get_visualizer(self):
         if self.viz == 'None':
             return None
 
+        viz_backend_package_name = 'pyRDDLGym'
+        spec = importlib.util.find_spec(viz_backend_package_name)
+        if spec is None:
+            raise RDDLRepoUnresolvedDependency(viz_backend_package_name + " is not installed")
+
         path_to_viz = self.loc.split('/')
         repo_root = path_to_viz.index('Archive')
         path_to_viz = '.'.join(path_to_viz[repo_root:])