Changes in / [a2e980b:cfc6f3c7] in sasview

Location:

src/sas/sascalc

Files:

• data_util/registry.py (modified) (7 diffs)
• dataloader/loader.py (modified) (4 diffs)
• dataloader/loader_exceptions.py (added)

src/sas/sascalc/data_util/registry.py

@@ -7 +7 @@
 """
 
-import os.path
+from sas.sascalc.dataloader.loader_exceptions import NoKnownLoaderException
+
 
 class ExtensionRegistry(object):
@@ -61 +62 @@
     def __init__(self, **kw):
         self.loaders = {}
+
     def __setitem__(self, ext, loader):
         if ext not in self.loaders:
             self.loaders[ext] = []
         self.loaders[ext].insert(0,loader)
+
     def __getitem__(self, ext):
         return self.loaders[ext]
+
     def __contains__(self, ext):
         return ext in self.loaders
+
     def formats(self):
         """
@@ -76 +81 @@
         names.sort()
         return names
+
     def extensions(self):
         """
@@ -83 +89 @@
         exts.sort()
         return exts
+
     def lookup(self, path):
         """
@@ -105 +112 @@
         # Raise an error if there are no matching extensions
         if len(loaders) == 0:
-            raise ValueError, "Unknown file type for "+path
+            raise ValueError("Unknown file type for "+path)
         # All done
         return loaders
+
     def load(self, path, format=None):
         """
@@ -117 +125 @@
         """
         if format is None:
-            loaders = self.lookup(path)
+            try:
+                loaders = self.lookup(path)
+            except ValueError as e:
+                pass
         else:
-            loaders = self.loaders[format]
+            try:
+                loaders = self.loaders[format]
+            except KeyError as e:
+                pass
         for fn in loaders:
             try:
                 return fn(path)
-            except:
-                pass # give other loaders a chance to succeed
+            except Exception as e:
+                pass  # give other loaders a chance to succeed
         # If we get here it is because all loaders failed
-        raise # reraises last exception
+        raise NoKnownLoaderException(e.message)  # raise generic exception
 
+
+# TODO: Move this to the unit test folder
 def test():
     reg = ExtensionRegistry()
@@ -163 +179 @@
     try: reg.load('hello.missing')
     except ValueError,msg:
-        assert str(msg)=="Unknown file type for hello.missing",'Message: <%s>'%(msg)
+        assert str(msg)=="Unknown file type for hello.missing",\
+            'Message: <%s>'%(msg)
     else: raise AssertError,"No error raised for missing extension"
     assert reg.formats() == ['new_cx']

src/sas/sascalc/dataloader/loader.py

@@ -1 +1 @@
 """
     File handler to support different file extensions.
-    Uses reflectometry's registry utility.
+    Uses reflectometer registry utility.
 
     The default readers are found in the 'readers' sub-module
@@ -29 +29 @@
 # Default readers are defined in the readers sub-module
 import readers
+from loader_exceptions import NoKnownLoaderException, FileContentsException
 from readers import ascii_reader
 from readers import cansas_reader
+from readers import cansas_reader_HDF5
+
 
 class Registry(ExtensionRegistry):
@@ -37 +40 @@
     Readers and writers are supported.
     """
-
     def __init__(self):
         super(Registry, self).__init__()
 
-        ## Writers
+        # Writers
         self.writers = {}
 
-        ## List of wildcards
+        # List of wildcards
         self.wildcards = ['All (*.*)|*.*']
 
-        ## Creation time, for testing
+        # Creation time, for testing
         self._created = time.time()
 
@@ -61 +63 @@
             of a particular reader
 
-        Defaults to the ascii (multi-column) reader
-        if no reader was registered for the file's
-        extension.
+        Defaults to the ascii (multi-column), cansas XML, and cansas NeXuS
+        readers if no reader was registered for the file's extension.
         """
         try:
             return super(Registry, self).load(path, format=format)
-        except:
-            try:
-                # No reader was found. Default to the ascii reader.
-                ascii_loader = ascii_reader.Reader()
-                return ascii_loader.read(path)
-            except:
-                cansas_loader = cansas_reader.Reader()
-                return cansas_loader.read(path)
+        except NoKnownLoaderException as e:
+            pass  # try the ASCII reader
+        except FileContentsException as e:
+            pass
+        try:
+            ascii_loader = ascii_reader.Reader()
+            return ascii_loader.read(path)
+        except FileContentsException:
+            pass  # try the cansas XML reader
+        try:
+            cansas_loader = cansas_reader.Reader()
+            return cansas_loader.read(path)
+        except FileContentsException:
+            pass  # try the cansas NeXuS reader
+        try:
+            cansas_nexus_loader = cansas_reader_HDF5.Reader()
+            return cansas_nexus_loader.read(path)
+        except FileContentsException:
+            # No known reader available. Give up and throw an error
+            msg = "\n\tUnknown data format: %s.\n\tThe file is not a " % path
+            msg += "known format that can be loaded by SasView."
+            raise NoKnownLoaderException(msg)
 
     def find_plugins(self, dir):