Added support for loading resources.

4 files changed, 46 insertions, 0 deletions

diff --git a/pluginbase.py b/pluginbase.py
index 426a105..1158ed9 100644
--- a/pluginbase.py
+++ b/pluginbase.py
@@ -9,8 +9,10 @@
     :copyright: (c) Copyright 2014 by Armin Ronacher.
     :license: BSD, see LICENSE for more details.
 """
+import os
 import sys
 import uuid
+import errno
 import pkgutil
 import hashlib
 import threading
@@ -23,9 +25,11 @@ PY2 = sys.version_info[0] == 2
 if PY2:
     text_type = unicode
     string_types = (unicode, str)
+    from cStringIO import StringIO as NativeBytesIO
 else:
     text_type = str
     string_types = (str,)
+    from io import BytesIO as NativeBytesIO
 
 
 _local = threading.local()
@@ -261,10 +265,36 @@ class PluginSource(object):
 
         :param name: the name of the plugin to load.
         """
+        if '.' in name:
+            raise ImportError('Plugin names cannot contain dots.')
         with self:
             return __import__(self.base.package + '.' + name,
                               globals(), {}, ['__name__'])
 
+    def open_resource(self, plugin, filename):
+        """This function locates a resource inside the plugin and returns
+        a byte stream to the contents of it.  If the resource cannot be
+        loaded an :exc:`IOError` will be raised.  Only plugins that are
+        real Python packages can contain resources.  Plain old Python
+        modules do not allow this for obvious reasons.
+
+        .. versionadded:: 0.3
+
+        :param plugin: the name of the plugin to open the resource of.
+        :param filename: the name of the file within the plugin to open.
+        """
+        mod = self.load_plugin(plugin)
+        fn = getattr(mod, '__file__', None)
+        if fn is not None:
+            if fn.endswith(('.pyc', '.pyo')):
+                fn = fn[:-1]
+            if os.path.isfile(fn):
+                return open(os.path.join(os.path.dirname(fn), filename), 'rb')
+        buf = pkgutil.get_data(self.mod.__name__ + '.' + plugin, filename)
+        if buf is None:
+            raise IOError(errno.ENOEXITS, 'Could not find resource')
+        return NativeBytesIO(buf)
+
     def cleanup(self):
         """Cleans up all loaded plugins manually.  This is necessary to
         call only if :attr:`persist` is enabled.  Otherwise this happens
@@ -369,6 +399,7 @@ class _ImportHook(ModuleType):
                 actual_name = space._rewrite_module_path(name)
                 if actual_name is not None:
                     import_name = actual_name
+
         return self._system_import(import_name, globals, locals,
                                    fromlist, level)
 
diff --git a/tests/plugins/withresources/__init__.py b/tests/plugins/withresources/__init__.py
new file mode 100644
index 0000000..9332a27
--- /dev/null
+++ b/tests/plugins/withresources/__init__.py
@@ -0,0 +1,2 @@
+def foo():
+    pass
diff --git a/tests/plugins/withresources/hello.txt b/tests/plugins/withresources/hello.txt
new file mode 100644
index 0000000..a670a4e
--- /dev/null
+++ b/tests/plugins/withresources/hello.txt
@@ -0,0 +1 @@
+I am a textfile.
diff --git a/tests/test_advanced.py b/tests/test_advanced.py
index d6440a5..15f668f 100644
--- a/tests/test_advanced.py
+++ b/tests/test_advanced.py
@@ -1,3 +1,6 @@
+import pytest
+
+
 def test_custom_state(base):
     class App(object):
         name = 'foobar'
@@ -6,3 +9,12 @@ def test_custom_state(base):
 
     plg = source.load_plugin('advanced')
     assert plg.get_app_name() == 'foobar'
+
+
+def test_plugin_resources(source):
+    with source.open_resource('withresources', 'hello.txt') as f:
+        contents = f.read()
+    assert contents == b'I am a textfile.\n'
+
+    with pytest.raises(IOError):
+        source.open_resource('withresources', 'missingfile.txt')