Implemented blueprints https://blueprints.launchpad.net/appy/+spec/gen-create-root-objects, https://blueprints.launchpad.net/appy/+spec/gen-get-flavour and https://blueprints.launchpad.net/appy/+spec/pod-define-variables

pod/actions.py

@@ -95,7 +95,7 @@ class BufferAction:
 
 class IfAction(BufferAction):
     '''Action that determines if we must include the content of the buffer in
-    the result or not.'''
+       the result or not.'''
     def do(self):
         if self.exprResult:
             self.evaluateBuffer()
@@ -122,7 +122,7 @@ class ElseAction(IfAction):
 
 class ForAction(BufferAction):
     '''Actions that will include the content of the buffer as many times as
-    specified by the action parameters.'''
+       specified by the action parameters.'''
     def __init__(self, name, buffer, expr, elem, minus, iter, source, fromExpr):
         BufferAction.__init__(self, name, buffer, expr, elem, minus, source,
                               fromExpr)
@@ -202,4 +202,28 @@ class NullAction(BufferAction):
        allows to insert in a buffer arbitrary odt content.'''
     def do(self):
         self.evaluateBuffer()
+
+class VariableAction(BufferAction):
+    '''Action that allows to define a variable somewhere in the template.'''
+    def __init__(self, name, buffer, expr, elem, minus, varName, source,
+        fromExpr):
+        BufferAction.__init__(self, name, buffer, expr, elem, minus, source,
+                              fromExpr)
+        self.varName = varName # Name of the variable
+    def do(self):
+        context = self.buffer.env.context
+        # Remember the variable hidden by our variable definition, if any
+        hasHiddenVariable = False
+        if context.has_key(self.varName):
+            hiddenVariable = context[self.varName]
+            hasHiddenVariable = True
+        # Add the variable to the context
+        context[self.varName] = self.exprResult
+        # Evaluate the buffer
+        self.evaluateBuffer()
+        # Restore hidden variable if any
+        if hasHiddenVariable:
+            context[self.varName] = hiddenVariable
+        else:
+            del context[self.varName]
 # ------------------------------------------------------------------------------

pod/buffers.py

@@ -21,7 +21,8 @@ import re
 
 from appy.pod import PodError, XML_SPECIAL_CHARS
 from appy.pod.elements import *
-from appy.pod.actions import IfAction, ElseAction, ForAction, NullAction
+from appy.pod.actions import IfAction, ElseAction, ForAction, VariableAction, \
+                             NullAction
 
 # ------------------------------------------------------------------------------
 class ParsingError(Exception): pass
@@ -62,6 +63,12 @@ ELSE_WITHOUT_IF = 'No previous "if" statement could be found for this "else" ' \
 ELSE_WITHOUT_NAMED_IF = 'I could not find an "if" statement named "%s".'
 BAD_FOR_EXPRESSION = 'Bad "for" expression "%s". A "for" expression ' + \
                      FOR_EXPRESSION
+BAD_VAR_EXPRESSION = 'Bad variable definition "%s". A variable definition ' \
+    'must have the form {name} = {expression}. {name} must be a Python-' \
+    'compliant variable name. {expression} is a Python expression. When ' \
+    'encountering such a statement, pod will define, in the specified part ' \
+    'of the document, a variable {name} whose value will be the evaluated ' \
+    '{expression}.'
 EVAL_EXPR_ERROR = 'Error while evaluating expression "%s". %s'
 NULL_ACTION_ERROR = 'There was a problem with this action. Possible causes: ' \
                     '(1) you specified no action (ie "do text") while not ' \
@@ -168,8 +175,9 @@ class FileBuffer(Buffer):
 # ------------------------------------------------------------------------------
 class MemoryBuffer(Buffer):
     actionRex = re.compile('(?:(\w+)\s*\:\s*)?do\s+(\w+)(-)?' \
-                           '(?:\s+(for|if|else)\s*(.*))?')
+                           '(?:\s+(for|if|else|with)\s*(.*))?')
     forRex = re.compile('\s*([\w\-_]+)\s+in\s+(.*)')
+    varRex = re.compile('\s*([\w\-_]+)\s+=\s+(.*)')
     def __init__(self, env, parent):
         Buffer.__init__(self, env, parent)
         self.content = u''
@@ -338,6 +346,13 @@ class MemoryBuffer(Buffer):
                 iter, subExpr = forRes.groups()
                 self.action = ForAction(statementName, self, subExpr, podElem,
                                         minus, iter, source, fromClause)
+            elif actionType == 'with':
+                varRes = MemoryBuffer.varRex.match(subExpr.strip())
+                if not varRes:
+                    raise ParsingError(BAD_VAR_EXPRESSION % subExpr)
+                varName, subExpr = varRes.groups()
+                self.action = VariableAction(statementName, self, subExpr,
+                    podElem, minus, varName, source, fromClause)
             else: # null action
                 if not fromClause:
                     raise ParsingError(NULL_ACTION_ERROR)

pod/odf_parser.py

@@ -48,4 +48,7 @@ class OdfEnvironment(XmlEnvironment):
 
 class OdfParser(XmlParser):
     '''XML parser that is specific for parsing ODF files.'''
+    def __init__(self, env=None, caller=None):
+        if not env: env = OdfEnvironment()
+        XmlParser.__init__(self, env, caller)
 # ------------------------------------------------------------------------------

pod/renderer.py

@@ -285,7 +285,7 @@ class Renderer:
         except OSError, oe:
             raise PodError(CANT_WRITE_RESULT % (self.result, oe))
         except IOError, ie:
-            raise PodError(CANT_WRITE_RESULT % (self.result, oe))
+            raise PodError(CANT_WRITE_RESULT % (self.result, ie))
         self.result = os.path.abspath(self.result)
         os.remove(self.result)
         # Check that temp folder does not exist

pod/test/contexts/VarStatements.py

@@ -0,0 +1,2 @@
+var1 = 'VAR1 not overridden'
+var2 = 'VAR2 not overridden'