work in progress: cybertools.meta - configuration settings framework

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@2517 fd906abe-77d9-0310-91a1-e0d9ade77398

meta/README.txt

@@ -31,8 +31,8 @@ Loading options as Python code
   >>> ex = Executor(config)
 
   >>> code = """
-  ... controller(names=['cmdline', 'telnet'])
+  ... controller(names=('cmdline', 'telnet'))
-  ... controller.telnet.port = 5001
+  ... controller.telnet(port= 5001)
   ... scheduler(name='core')
   ... logger(name='default', standard=30)
   ... """
@@ -43,3 +43,14 @@ Loading options as Python code
   'core'
   >>> config.logger.standard
   30
+  >>> config.controller.names
+  ('cmdline', 'telnet')
+  >>> config.controller.telnet.port
+  5001
+
+  >>> print config
+  controller.telnet(port=5001)
+  controller(names=('cmdline', 'telnet'))
+  scheduler(name='core')
+  logger(name='default', standard=30)
+

meta/config.py

@@ -24,14 +24,42 @@ $Id$
 
 from zope.interface import implements
 
-from cybertools.meta.interfaces import IOptions
+from cybertools.meta.interfaces import IOptions, IConfigurator
-from cybertools.meta.namespace import AutoNamespace
+from cybertools.meta.namespace import AutoNamespace, Executor, ExecutionError
 
 
 class Options(AutoNamespace):
 
     implements(IOptions)
 
-    def __init__(self, context=None):
+
+class Configurator(object):
+
+    implements(IConfigurator)
+
+    def __init__(self, context):
         self.context = context
 
+    def load(self, text=None, file=None):
+        if file is not None:
+            if hasattr(file, 'read'):
+                text = file.read()
+            else:   # must be a file name
+                f = open(file, 'r')
+                text = f.read()
+                f.close()
+        result = Executor(self.context).execute(text)
+        if result:
+            raise ExecutionError('\n' + result)
+
+    def dump(self, file=None):
+        text = str(options)
+        if file is not None:
+            if hasattr(file, 'write'):
+                file.write(text)
+            else:   # must be a file name
+                f = open(file, 'w')
+                f.write(text)
+                f.close()
+        return text
+

meta/element.py

@@ -23,6 +23,8 @@ elements.
 $Id$
 """
 
+from cStringIO import StringIO
+
 from cybertools.util.jeep import Jeep
 
 _not_found = object()
@@ -31,28 +33,25 @@ _not_found = object()
 class Element(dict):
 
     typeName = 'Element'
-    posArgs = ('name',)
+    posArgs = ('__name__',)
+    realAttributes = ('namespace', '__name__', 'factory', 'parent', 'children')
 
-    def __init__(self, namespace, name, collection=None, parent=None):
+    def __init__(self, namespace, name, factory=None, parent=None):
         self.namespace = namespace
-        self.name = name
+        self.__name__ = name
-        self.collection = collection
         self.parent = parent
+        self.factory = factory
         self.children = Jeep()
 
     def __call__(self, *args, **kw):
-        elem = self.__class__(self.namespace, '')
         for idx, v in enumerate(args):
-            if idx < len(self.posArgs):
+            if isinstance(v, Element):
-                elem[self.posArgs[idx]] = v
+                self[v.__name__] = v
+            elif idx < len(self.posArgs):
+                self[self.posArgs[idx]] = v
         for k, v in kw.items():
-            elem[k] = v
+            self[k] = v
-        elem.name = elem.get('name')
+        return self
-        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)):
@@ -67,45 +66,62 @@ class Element(dict):
 
     def __getattr__(self, key):
         result = self.get(key, _not_found)
+        if result is _not_found:
+            result = self.children.get(key, _not_found)
             if result is _not_found:
                 raise AttributeError(key)
         return result
 
+    def __setattr__(self, key, value):
+        if key in self.realAttributes:
+            super(Element, self).__setattr__(key, value)
+        else:
+            self[key] = value
+
     def __iter__(self):
         return iter(self.children)
 
     def __str__(self):
-        return self.name
+        return self.__name__
 
     def __repr__(self):
-        return "<%s '%s'>" % (self.typeName, self.name)
+        return "<%s '%s'>" % (self.typeName, self.__name__)
+
+
+class ElementFactory(object):
+
+    elementClass = Element
+
+    def __init__(self, namespace, name):
+        self.namespace = namespace
+        self.__name__ = name
+        self.instances = []
+
+    def __call__(self, *args, **kw):
+        elem = self.elementClass(self.namespace, '', factory=self)
+        for idx, v in enumerate(args):
+            if idx < len(elem.posArgs):
+                elem[elem.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__
+        self.instances.append(elem)
+        return elem
 
 
 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.children.get(key, _not_found)
             if result is _not_found:
                 result = self.__class__(self.namespace, key, parent=self)
-            self[key] = result
+                self.children[key] = result
         return result
 
     def __getitem__(self, key):
@@ -118,3 +134,16 @@ class AutoElement(Element):
                 return result
             else:
                 raise KeyError(key)
+
+    def __str__(self):
+        out = StringIO()
+        for v in self.children:
+            out.write('%s.%s\n' % (self.__name__, v))
+        if self or not self.children:
+            out.write(self.__name__)
+        if self:
+            out.write('(')
+            out.write(', '.join('%s=%r' % (k, v) for k, v in self.items()))
+            out.write(')')
+        return out.getvalue()
+

meta/interfaces.py

@@ -27,5 +27,52 @@ from zope.interface import Interface, Attribute
 
 class IOptions(Interface):
     """ Provide a set of options (settings, configuration options,
-        preferences) based on a given context object.
+        preferences) based on a given context object or loaded from
+        a file.
+    """
+
+    def __contains__(key):
+        """ Return True if this object provides the option identified
+            by the key given.
+        """
+
+    def __iter__():
+        """ Return an iterator over the option keys provided by this
+            object.
+        """
+
+    def values():
+        """ Return an iterator over all settings.
+        """
+
+    def __getitem__(key):
+        """ Return the value belonging to the key given.
+        """
+
+    def __getattr__(key):
+        """ Return the value belonging to the key given
+            (same as ``__getitem__()``).
+        """
+
+    def __str__():
+        """ Return a string representation that shows all settings.
+        """
+
+
+class IConfigurator(Interface):
+    """ Adapter for an IOptions object that allows loading and saving
+        of configuration settings.
+    """
+
+    def load(text=None, file=None):
+        """ Load settings from the string or the file given.
+
+            The ``file`` argument may be a string - that will be interpreted
+            as a file name or path - or a file object
+        """
+
+    def dump(file=None):
+        """ Return a string representation of the context's configuration
+            settings; if ``file`` is given write the representation to
+            the corresponding file object.
         """

meta/namespace.py

@@ -34,11 +34,11 @@ _not_found = object()
 
 class BaseNamespace(dict):
 
-    builtins = 'dir', 'output'
+    builtins = '__builtins__', 'dir', 'output'
 
     def __init__(self, *args, **kw):
+        self.__builtins__ = {}
         super(BaseNamespace, self).__init__(*args, **kw)
-        self['__builtins__'] = {}
         for key in self.builtins:
             self[key] = getattr(self, key)
 
@@ -62,24 +62,33 @@ class BaseNamespace(dict):
             raise AttributeError(key)
         return result
 
+    def __str__(self):
+        def result():
+            for k, v in self.items():
+                if k not in self.builtins:
+                    if isinstance(v, Element):
+                        yield str(v)
+                    else:
+                        yield '%s=%r' % (k, v)
+        return '\n'.join(list(result()))
+
+    __repr__ = object.__repr__
+
 
 class AutoNamespace(BaseNamespace):
 
     elementFactory = AutoElement
 
     def __getitem__(self, key):
-        result = self.get(key, _not_found)
-        if result is _not_found:
-            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
 
+    def __getattr__(self, key):
+        return self[key]
+
 
 class Executor(object):
 
@@ -129,3 +138,8 @@ class Evaluator(Executor):
         except:
             error = traceback.format_exc()
         return result, error
+
+
+class ExecutionError(ValueError):
+
+    pass

meta/namespace.txt

@@ -62,20 +62,21 @@ Elements and sub-elements (children)
   ... """
 
   >>> from cybertools.util.jeep import Jeep
-  >>> from cybertools.meta.element import Element
+  >>> from cybertools.meta.element import ElementFactory
-  >>> topics = Jeep()
   >>> symbols = namespace.BaseNamespace()
-  >>> symbols['topic'] = Element(symbols, 'topic', topics)
+  >>> symbols['topic'] = ElementFactory(symbols, 'topic')
-  >>> symbols['annotation'] = Element(symbols, 'annotation')
+  >>> symbols['annotation'] = ElementFactory(symbols, 'annotation')
-  >>> symbols['child'] = Element(symbols, 'child')
+  >>> symbols['child'] = ElementFactory(symbols, 'child')
 
   >>> exec code in symbols
 
-  >>> dict(topics)
+  >>> symbols.topic.instances
-  {'python': <Element 'python'>, 'zope3': <Element 'zope3'>}
+  [<Element 'zope3'>, <Element 'python'>]
-
+  >>> zope3 = symbols.topic.instances[0]
-  >>> dict(topics['python'].children)
+  >>> dict(zope3.annotation)
-  {'zope3': <Element 'zope3'>, 'annotation': <Element 'annotation'>}
+  {'author': 'jim'}
+  >>> zope3.title
+  'Zope 3'
 
 
 A Namespace Automatically Generating Elements