Starting work on making servers pluggable (have to commit as I rearrange files)

1 files changed, 54 insertions, 0 deletions

diff --git a/paste/util/plugin.py b/paste/util/plugin.py
new file mode 100644
index 0000000..2e61294
--- /dev/null
+++ b/paste/util/plugin.py
@@ -0,0 +1,54 @@
+import os
+import import_string
+
+paste_dir = os.path.dirname(os.path.dirname(__file__))
+
+def find_plugins(dir):
+    """
+    Looks in directory for plugins, and returns them by name.
+    A plugin can be a .txt file, .py file, or directory.
+    """
+    plugins = []
+    dir = os.path.join(paste_dir, dir))
+    for name in os.listdir(dir):
+        if os.path.isdir(os.path.join(dir, name)):
+            plugins.append(name)
+        ext = os.path.splitext(name)[1].lower()
+        if name in ('.py', '.txt'):
+            plugins.append(name)
+    return plugins
+
+def load_plugin_module(dir, dir_package, name):
+    """
+    Loads a plugin module.  Either the module is imported, or if it
+    is a .txt file then the file is loaded and must contain the name
+    of another module to be loaded (empty and comment lines ignored).
+
+    dir_package is the package name of the directory.  Dotted names
+    are not supported.
+    """
+    dir = os.path.join(paste_dir, dir)
+    if os.path.exists(os.path.join(dir, name + '.txt')):
+        module_name = parse_txt_plugin(os.path.join(dir, name + '.txt'))
+    else:
+        module_name = dir_package + '.' + name
+    return import_string.import_module(module_name)
+
+def parse_txt_plugin(fn):
+    f = open(fn)
+    try:
+        module_name = None
+        for line in f:
+            line = line.strip()
+            if not line or line.startswith('#'):
+                continue
+            if module_name is not None:
+                raise ValueError(
+                    "Plugin file %s contains more than one line that "
+                    "could be interpreted as a module name" % fn)
+        if module_name is None:
+            raise ValueError(
+                "Plugin file %s does not contain a module name" % fn)
+        return module_name
+    finally:
+        f.close()