[Fix #2] Implement lifecycle hooks

graaf/__init__.py

@@ -29,6 +29,9 @@ def run(self):
 
         self.context = Context({})
 
+        for generator in self.generators:
+            generator.start(self)
+
         for root, dirs, files in os.walk(self.srcdir):
             print "Scanning: %r (%d files)" % (root, len(files))
             dest_root = os.path.join(self.destdir, root[len(self.srcdir):])
@@ -37,6 +40,9 @@ def run(self):
             except OSError:
                 pass
 
+            for generator in self.generators:
+                generator.enter_dir(root, dirs, files)
+
             self.context.push(**get_yaml(os.path.join(root, '_.yml')))
 
             for filename in files:
@@ -51,6 +57,12 @@ def run(self):
 
             self.context.pop()
 
+            for generator in self.generators:
+                generator.leave_dir(root, dirs, files)
+
+        for generator in self.generators:
+            generator.finish(self)
+
     def render(self, template_name, extra_context):
         '''
         Helper function to render a template with the current context, and extra

graaf/base.py

@@ -28,6 +28,25 @@ def write_file(self, dest_dir, filename, content):
         with io.open(os.path.join(dest_dir, filename), mode='w', encoding='utf-8') as fout:
             fout.write(content)
 
+    def start(self, processor):
+        '''
+        Hook to alow Generators to react to start of processing.
+        '''
+        pass
+
+    def enter_dir(self, src_dir, dirs, files):
+        '''
+        Hook to allow Generators to react to start of processing a dir.
+        '''
+        pass
+
+    def leave_dir(self, src_dir, dirs, files):
+        '''
+        Hook to allow Generators to react to end of processing a dir.
+        '''
+        pass
+
+
 
 def get_yaml(src):
     '''