implement actual Rewriting logic

passbook/app_gw/rewrite.py

@@ -0,0 +1,38 @@
+"""passbook app_gw rewriter"""
+
+from passbook.app_gw.models import RewriteRule
+
+
+class Context:
+    """Empty class which we dynamically add attributes to"""
+
+class Rewriter:
+    """Apply rewrites"""
+
+    __application = None
+    __request = None
+
+    def __init__(self, application, request):
+        self.__application = application
+        self.__request = request
+
+    def __build_context(self, matches):
+        """Build object with .0, .1, etc as groups and give access to request"""
+        context = Context()
+        for index, group_match in enumerate(matches.groups()):
+            setattr(context, "g%d" % (index + 1), group_match)
+        setattr(context, 'request', self.__request)
+        return context
+
+    def build(self):
+        """Run all rules over path and return final path"""
+        path = self.__request.get_full_path()
+        for rule in RewriteRule.objects.filter(provider__in=[self.__application]):
+            matches = rule.compiled_matcher.search(path)
+            if not matches:
+                continue
+            replace_context = self.__build_context(matches)
+            path = rule.replacement.format(context=replace_context)
+            if rule.halt:
+                return path
+        return path