work in progress: cybertools.meta package for managing general meta-information, e.g. for configuration settings and preferences

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@2516 fd906abe-77d9-0310-91a1-e0d9ade77398

meta/README.txt

@@ -10,3 +10,36 @@ Configuration Options, Settings, Preferences
 
   >>> from cybertools.meta.config import Options
 
+  >>> config = Options()
+
+The Options object allows us to access arbitrary attributes that will
+be created as elements within the Options object.
+
+  >>> config.storage
+  <AutoElement 'storage'>
+
+  >>> config.i18n.languages = ['de', 'en', 'it']
+
+  >>> config.i18n.languages
+  ['de', 'en', 'it']
+
+Loading options as Python code
+------------------------------
+
+  >>> from cybertools.meta.namespace import Executor
+  >>> config = Options()
+  >>> ex = Executor(config)
+
+  >>> code = """
+  ... controller(names=['cmdline', 'telnet'])
+  ... controller.telnet.port = 5001
+  ... scheduler(name='core')
+  ... logger(name='default', standard=30)
+  ... """
+
+  >>> result = ex.execute(code)
+
+  >>> config.scheduler.name
+  'core'
+  >>> config.logger.standard
+  30

meta/config.py

@@ -22,17 +22,16 @@ Basic implementations for configuration options
 $Id$
 """
 
-from zope.component import adapts
-from zope.interface import implements, Interface
+from zope.interface import implements
 
 from cybertools.meta.interfaces import IOptions
+from cybertools.meta.namespace import AutoNamespace
 
 
-class Options(object):
+class Options(AutoNamespace):
 
     implements(IOptions)
-    adapts(Interface)
 
-    def __init__(self, context):
+    def __init__(self, context=None):
         self.context = context
 

meta/element.py

@@ -0,0 +1,120 @@
+#
+#  Copyright (c) 2008 Helmut Merz helmutm@cy55.de
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+"""
+Building flexible hierarchical object structures with XML-like
+elements.
+
+$Id$
+"""
+
+from cybertools.util.jeep import Jeep
+
+_not_found = object()
+
+
+class Element(dict):
+
+    typeName = 'Element'
+    posArgs = ('name',)
+
+    def __init__(self, namespace, name, collection=None, parent=None):
+        self.namespace = namespace
+        self.name = name
+        self.collection = collection
+        self.parent = parent
+        self.children = Jeep()
+
+    def __call__(self, *args, **kw):
+        elem = self.__class__(self.namespace, '')
+        for idx, v in enumerate(args):
+            if idx < len(self.posArgs):
+                elem[self.posArgs[idx]] = v
+        for k, v in kw.items():
+            elem[k] = v
+        elem.name = elem.get('name')
+        if not elem.name:
+            elem.name = self.name
+        if self.collection is not None:
+            self.collection.append(elem)
+        return elem
+
+    def __getitem__(self, key):
+        if isinstance(key, (list, tuple)):
+            return tuple(self[k] for k in key)
+        elif isinstance(key, Element):
+            self.children.append(key)
+            return key
+        elif isinstance(key, (int, long, basestring)):
+            return self.children[key]
+        else:
+            raise KeyError(key)
+
+    def __getattr__(self, key):
+        result = self.get(key, _not_found)
+        if result is _not_found:
+            raise AttributeError(key)
+        return result
+
+    def __iter__(self):
+        return iter(self.children)
+
+    def __str__(self):
+        return self.name
+
+    def __repr__(self):
+        return "<%s '%s'>" % (self.typeName, self.name)
+
+
+class AutoElement(Element):
+
+    typeName = 'AutoElement'
+
+    def __call__(self, *args, **kw):
+        if self.collection is None:
+            elem = self
+        else:
+            elem = self.__class__(self.namespace, '')
+            self.collection.append(elem)
+        for idx, v in enumerate(args):
+            if idx < len(self.posArgs):
+                elem[self.posArgs[idx]] = v
+        for k, v in kw.items():
+            elem[k] = v
+        elem.name = elem.get('name')
+        if not elem.name:
+            elem.name = self.name
+        return elem
+
+    def __getattr__(self, key):
+        result = self.get(key, _not_found)
+        if result is _not_found:
+            result = self.__class__(self.namespace, key, parent=self)
+            self[key] = result
+        return result
+
+    def __getitem__(self, key):
+        try:
+            return super(AutoElement, self).__getitem__(key)
+        except KeyError:
+            if isinstance(key, basestring):
+                result = self.__class__(self.namespace, key, parent=self)
+                self.children[key] = result
+                return result
+            else:
+                raise KeyError(key)

meta/namespace.py

@@ -26,6 +26,7 @@ $Id$
 
 import traceback
 
+from cybertools.meta.element import Element, AutoElement
 from cybertools.util.jeep import Jeep
 
 _not_found = object()
@@ -62,60 +63,21 @@ class BaseNamespace(dict):
         return result
 
 
-class Element(object):
-
-    posArgs = ('name',)
-
-    def __init__(self, namespace, name, collection=None, parent=None):
-        self.namespace = namespace
-        self.name = name
-        self.collection = collection
-        self.parent = parent
-        self.subElements = Jeep()
-
-    def __call__(self, *args, **kw):
-        elem = self.__class__(self.namespace, '', parent=self)
-        for idx, v in enumerate(args):
-            if idx < len(self.posArgs):
-                setattr(elem, self.posArgs[idx], v)
-        for k, v in kw.items():
-            setattr(elem, k, v)
-        if not elem.name:
-            elem.name = self.name
-        if self.collection is not None:
-            self.collection.append(elem)
-        return elem
-
-    def __getitem__(self, key):
-        if isinstance(key, (list, tuple)):
-            return tuple(self[k] for k in key)
-        elif isinstance(key, Element):
-            self.subElements.append(key)
-            return key
-        elif isinstance(key, (int, long, basestring)):
-            return self.subElements[key]
-        else:
-            print '*** Error', key
-
-    def __str__(self):
-        return self.name
-
-    def __repr__(self):
-        return "<Element '%s'>" % self.name
-
-
 class AutoNamespace(BaseNamespace):
 
-    elementFactory = Element
+    elementFactory = AutoElement
 
     def __getitem__(self, key):
         result = self.get(key, _not_found)
         if result is _not_found:
-            result = getattr(self, key, _not_found)
-            if result is _not_found:
-                elem = Element(self, key)
-                self[key] = elem
-                return elem
+            result = getattr(self, key)
+        return result
+
+    def __getattr__(self, key):
+        result = self.get(key, _not_found)
+        if result is _not_found:
+            result = self.elementFactory(self, key)
+            self[key] = result
         return result
 
 

meta/namespace.txt

@@ -50,8 +50,8 @@ namespace provides a secure restricted execution environment.
   ...
   NameError: open
 
-Elements and sub-elements
--------------------------
+Elements and sub-elements (children)
+------------------------------------
 
   >>> code = """
   ... topic('zope3', title='Zope 3')[
@@ -62,18 +62,19 @@ Elements and sub-elements
   ... """
 
   >>> from cybertools.util.jeep import Jeep
+  >>> from cybertools.meta.element import Element
   >>> topics = Jeep()
   >>> symbols = namespace.BaseNamespace()
-  >>> symbols['topic'] = namespace.Element(symbols, 'topic', topics)
-  >>> symbols['annotation'] = namespace.Element(symbols, 'annotation')
-  >>> symbols['child'] = namespace.Element(symbols, 'child')
+  >>> symbols['topic'] = Element(symbols, 'topic', topics)
+  >>> symbols['annotation'] = Element(symbols, 'annotation')
+  >>> symbols['child'] = Element(symbols, 'child')
 
   >>> exec code in symbols
 
   >>> dict(topics)
   {'python': <Element 'python'>, 'zope3': <Element 'zope3'>}
 
-  >>> dict(topics['python'].subElements)
+  >>> dict(topics['python'].children)
   {'zope3': <Element 'zope3'>, 'annotation': <Element 'annotation'>}
 
 
@@ -86,7 +87,7 @@ A Namespace Automatically Generating Elements
   something
 
   >>> auto.something
-  <Element 'something'>
+  <AutoElement 'something'>
 
 
 Execution of Python Code in a Namespace

meta/tests.py

@@ -11,7 +11,7 @@ from zope.testing.doctestunit import DocFileSuite
 
 
 class Test(unittest.TestCase):
-    "Basic tests for the storage package."
+    "Basic tests for the meta package."
 
     def testBasicStuff(self):
         pass

util/jeep.py

@@ -111,7 +111,7 @@ class Jeep(object):
         if key is _notfound:
             raise AttributeError("No name attribute present")
         if key in self.keys():
-            raise ValueError("Object already present")
+            raise ValueError("Object '%s' already present" % key)
         self._sequence.insert(idx, key)
         object.__setattr__(self, key, obj)