More robust module loading

hyde/loader.py

@@ -0,0 +1,42 @@
+"""
+Generic loader of extensions (plugins & templates)
+"""
+import sys
+
+from hyde.exceptions import HydeException
+
+plugins = {}
+templates = {}
+
+
+def load_python_object(name):
+    """
+    Loads a python module from string
+    """
+    (module_name, _, object_name) = name.rpartition(".")
+    if module_name == '':
+        (module_name, object_name) = (object_name, module_name)
+    try:
+        module = __import__(module_name)
+    except ImportError:
+        raise HydeException("The given module name [%s] is invalid." %
+                            module_name)
+
+    if object_name == '':
+        return module
+
+    try:
+        module = sys.modules[module_name]
+    except KeyError:
+        raise HydeException("Error occured when loading module [%s]" %
+                            module_name)
+
+    try:
+        return getattr(module, object_name)
+    except AttributeError:
+        raise HydeException("Cannot load the specified plugin [%s]. "
+                            "The given module [%s] does not contain the "
+                            "desired object [%s]. Please fix the"
+                            "configuration or ensure that the module is "
+                            "installed properly" %
+                            (name, module_name, object_name))

hyde/tests/test_loader.py

@@ -0,0 +1,54 @@
+# -*- coding: utf-8 -*-
+"""
+Use nose
+`$ pip install nose`
+`$ nosetests`
+"""
+
+from hyde.loader import load_python_object
+from nose.tools import raises
+import os
+
+from hyde.exceptions import HydeException
+
+
+def test_can_load_locals():
+
+    file_class = load_python_object('hyde.fs.File')
+    assert file_class
+
+    f = file_class(__file__)
+    assert f
+
+    assert f.name == os.path.basename(__file__)
+
+
+def test_can_load_from_python_path():
+
+    markdown = load_python_object('markdown.markdown')
+    assert markdown
+
+    assert "<h3>h3</h3>" == markdown("### h3")
+
+def test_can_load_module_without_dot():
+
+    yaml = load_python_object('yaml')
+
+    abc = yaml.load("""
+        d: efg
+        l: mno
+    """)
+
+    assert abc['d'] == 'efg'
+    assert abc['l'] == 'mno'
+
+
+@raises(HydeException)
+def test_exception_raised_for_invalid_module():
+    load_python_object("junk.junk.junk")
+    assert False
+
+@raises(HydeException)
+def test_exception_raised_for_invalid_object():
+    load_python_object("markdown.junk")
+    assert False

hyde/tests/test_util.py

@@ -1,19 +0,0 @@
-# -*- coding: utf-8 -*-
-"""
-Use nose
-`$ pip install nose`
-`$ nosetests`
-"""
-
-from hyde.util import load_python_object
-import os
-
-def test_can_load_locals():
-
-    file_class = load_python_object('hyde.fs.File')
-    assert file_class
-
-    f = file_class(__file__)
-    assert f
-
-    assert f.name == os.path.basename(__file__)

hyde/util.py

@@ -1,14 +0,0 @@
-"""
-Hyde utilities
-"""
-import sys
-
-
-def load_python_object(name):
-    """
-    Loads a python module from string
-    """
-    (module_name, _ , object_name) = name.rpartition(".")
-    __import__(module_name)
-    module = sys.modules[module_name]
-    return getattr(module, object_name)