add support for chaining and nesting of recipes

saucebrush/__init__.py

@@ -8,16 +8,25 @@ class Recipe(filters.Filter):
     
     def __init__(self, *filter_args):
         self._filter_args = filter_args
-        self._rejected = []
+        self.rejected = []
     
-    def process_record(self, record):
-        self.run(source=iter((record,)))
+    def get_filters(self):
+        filters = []
+        for filter_ in self._filter_args:
+            if hasattr(filter_, 'get_filters'):
+                filters.extend(filter_.get_filters())
+            else:
+                filters.append(filter_)
+        return filters
     
     def run(self, source):
         
+        # load filters
+        filters = self.get_filters()
+        
         # connect datapath
         data = source
-        for filter_ in self._filter_args:
+        for filter_ in filters:
             data = filter_(self, data)
 
         # actually run the data through (causes iterators to actually be called)
@@ -25,17 +34,19 @@ class Recipe(filters.Filter):
             pass
 
         # try and call done() on all filters
-        for filter_ in self._filter_args:
+        for filter_ in filters:
             try:
                 filter_.done()
             except AttributeError:
                 pass    # don't care if there isn't a done method
+        
+        return self
 
 def run_recipe(source, *filter_args):
     """ Process data, taking it from a source and applying any number of filters
     """
     
-    Recipe(*filter_args).run(source)
+    return Recipe(*filter_args).run(source)
 
 
 # experiment with threading - do not use

saucebrush/filters.py

@@ -33,7 +33,12 @@ class Filter(object):
         raise NotImplementedError('process_record not defined in ' +
                                   self.__class__.__name__)
 
+    def reject_record(self, record, message):
+        if hasattr(self, '_recipe'):
+            self._recipe.rejected.append((record, message))
+
     def __call__(self, recipe, source):
+        self._recipe = recipe
         for record in source:
             result = self.process_record(record)
             if not result is None: