serializing of classes to XML,JSON,YAML

corepost/__init__.py

@@ -10,3 +10,6 @@ class Response:
         self.code = code
         self.entity=entity
         self.headers=headers  
+        
+    def __str__(self):
+        return str(self.__dict__)
\ No newline at end of file

corepost/convert.py

+'''
+Created on 2011-10-11
+@author: jacekf
+
+Responsible for converting return values into cleanly serializable dict/tuples/lists
+for JSON/XML/YAML output
+'''
+
+import inspect, collections
+from jinja2 import Template
+
+xmlListTemplate = Template("""<list>{% for item in items %}<item>{% for prop,val in item.iteritems() %}<{{prop}}>{{val}}</{{prop}}>{% endfor %}</item>{% endfor %}</list>""")
+xmlTemplate = Template("""<item>{% for prop,val in item.iteritems() %}<{{prop}}>{{val}}</{{prop}}>{% endfor %}</item>""")
+
+def convertForSerialization(object):
+    """Converts anything (clas,tuples,list) to the safe serializable equivalent"""
+    if isinstance(object, dict):
+        return traverseDict(object)
+    elif isClassInstance(object):
+        return convertClassToDict(object)
+    elif isinstance(object,collections.Iterable):
+        # iterable
+        values = []
+        for val in object:
+            values.append(convertForSerialization(val))
+        return values
+    else:
+        # return as-is
+        return object
+
+def convertClassToDict(clazz):
+    """Converts a class to a dictionary"""
+    properties = {}
+
+    for prop,val in clazz.__dict__.iteritems():
+        #omit private fields
+        if not prop.startswith("_"):
+            properties[prop] = val
+    
+    return traverseDict(properties)
+
+def traverseDict(dictObject):
+    """Traverses a dict recursively to convertForSerialization any nested classes"""
+    newDict = {}
+    for prop,val in dictObject.iteritems():
+        if inspect.isclass(val):
+            # call itself recursively
+            val = convertClassToDict(val)
+
+        newDict[prop] = val
+    
+    return newDict
+    
+def generateXml(object):
+    """Generates basic XML from an object that has already been converted for serialization"""
+    if isinstance(object,dict):
+        return str(xmlTemplate.render(item=object.keys()))
+    elif isinstance(object,collections.Iterable):
+        return str(xmlListTemplate.render(items=object))
+    else:
+        raise RuntimeError("Unable to convert to XML: %s" % object)    
+    
+def isClassInstance(object):
+    """Checks if a given object is a class instance"""
+    return getattr(object, "__class__",None) != None and not isinstance(object,dict) and not isinstance(object,tuple) and not isinstance(object,list)
\ No newline at end of file

corepost/routing.py

@@ -7,6 +7,7 @@ Common routing classes, regardless of whether used in HTTP or ZeroMQ context
 from collections import defaultdict
 from corepost.enums import Http, HttpHeader
 from corepost.utils import getMandatoryArgumentNames, convertToJson
+from corepost.convert import convertForSerialization, generateXml
 from corepost import Response
 from enums import MediaType
 from formencode import FancyValidator, Invalid
@@ -251,6 +252,8 @@ class RequestRouter:
         Takes care of converting an object (non-String) response to the appropriate format, based on the what the caller can accept.
         Returns a tuple of (content,contentType)
         """
+        obj = convertForSerialization(obj)
+        
         if HttpHeader.ACCEPT in request.received_headers:
             accept = request.received_headers[HttpHeader.ACCEPT]
             if MediaType.APPLICATION_JSON in accept:
@@ -258,10 +261,7 @@ class RequestRouter:
             elif MediaType.TEXT_YAML in accept:
                 return (yaml.dump(obj),MediaType.TEXT_YAML)
             elif MediaType.APPLICATION_XML in accept or MediaType.TEXT_XML in accept:
-                if isinstance(obj,Element):
-                    return (ElementTree.tostring(obj, encoding='utf-8'),MediaType.APPLICATION_XML)
-                else:
-                    raise RuntimeError("Unable to convert String response to XML automatically")
+                return (generateXml(obj),MediaType.APPLICATION_XML+";charset=utf-8")
             else:
                 # no idea, let's do JSON
                 return (convertToJson(obj),MediaType.APPLICATION_JSON)
@@ -271,7 +271,9 @@ class RequestRouter:
 
     def __finishDeferred(self,val,request):
         """Finishes any Defered/inlineCallback methods. Returns Response"""
-        if val != None:
+        if isinstance(val,Response):
+            return val
+        elif val != None:
             try:
                 return self.__generateResponse(request,val)
             except Exception as ex:

corepost/test/feature/content_types.feature

@@ -183,10 +183,10 @@ total: 4443.52
 		Examples:
 			| content																			| accept				| code 	|  
 			| [{"test1": "Test1"}, {"test2": "Test2"}]											| application/json	 	| 200	|
-			| Unable to convert String response to XML automatically	| application/xml	 	| 500	| # not supported yet
+			| <list><item><test1>Test1</test1></item><item><test2>Test2</test2></item></list>	| application/xml	 	| 200	| 
 			| - {test1: Test1}\n- {test2: Test2}												| text/yaml				| 200	|
 			
-	@json @yaml @xml @return_accept_deferred @tmp
+	@json @yaml @xml @return_accept_deferred
 	Scenario Outline: Return content type based on caller's Accept from Deferred methods
 		When I prepare HTTP header 'Accept' = '<accept>'
 		When as user 'None:None' I GET 'http://127.0.0.1:8080/return/by/accept/deferred'
@@ -196,10 +196,10 @@ total: 4443.52
 		Examples:
 			| content																			| accept				| code 	|  
 			| [{"test1": "Test1"}, {"test2": "Test2"}]											| application/json	 	| 200	|
-			#| Unable to convert String response to XML automatically	| application/xml	 	| 500	| # not supported yet
-			#| - {test1: Test1}\n- {test2: Test2}						| text/yaml				| 200	|			
+			| <list><item><test1>Test1</test1></item><item><test2>Test2</test2></item></list>	| application/xml	 	| 200	|
+			| - {test1: Test1}\n- {test2: Test2}												| text/yaml				| 200	|			
 			
-	@json @yaml @xml @return_accept 
+	@json @yaml @xml @return_accept @tmp
 	Scenario Outline: Return class content type based on caller's Accept
 		When I prepare HTTP header 'Accept' = '<accept>'
 		When as user 'None:None' I GET 'http://127.0.0.1:8080/return/by/accept/class'
@@ -208,6 +208,7 @@ total: 4443.52
 		
 		Examples:
 			| content																			| accept				| code 	|  
-			| [{}, {}]													| application/json	 	| 200	| # not supported yet
-			| Unable to convert String response to XML automatically	| application/xml	 	| 500	| # not supported yet
+			| [{"test1": "Test1"}, {"test2": "Test2"}]											| application/json	 	| 200	| # not supported yet
+			| <list><item><test1>Test1</test1></item><item><test2>Test2</test2></item></list>	| application/xml	 	| 200	| # not supported yet
+			| - {test1: Test1}\n- {test2: Test2}												| text/yaml			 	| 200	| # not supported yet
 			
\ No newline at end of file

corepost/test/home_resource.py

@@ -92,14 +92,17 @@ class HomeApp(CorePost):
     @route("/return/by/accept/class")
     def test_return_class_content_by_accepts(self,request,**kwargs):
         """Uses Python class instead of dict/list"""
-        class Test(UserDict,dict):
-            pass
         
-        t1 = Test()
-        t1.test1="Test1"
-        t2 = Test()
+        class TestReturn:
+            """Test return class"""
+            def __init__(self):
+                self.__t1 = 'Test'
+        
+        t1 = TestReturn()
+        t1.test1 = 'Test1'
+        
+        t2 = TestReturn()
         t2.test2="Test2"
-        val = [t1,t2]
         return (t1,t2)
 
 

corepost/utils.py

@@ -3,7 +3,6 @@ Various CorePost utilities
 '''
 from inspect import getargspec
 import json
-from corepost.enums import MediaType
 
 def getMandatoryArgumentNames(f):
     '''Returns a tuple of the mandatory arguments required in a function'''
@@ -23,10 +22,3 @@ def convertToJson(obj):
         return json.dumps(obj)
     except Exception as ex:
         raise RuntimeError(str(ex))
-    
-def applyResponse(self,request,code,headers={"content-type":MediaType.TEXT_PLAIN}):
-    """Applies response to current request"""
-    request.setResponseCode(code)
-    if headers != None:
-        for header,value in headers.iteritems():
-            request.setHeader(header, value)

corepost/web.py

@@ -51,6 +51,7 @@ class CorePost(Resource):
     def __renderUrl(self,request):
         try:
             val = self.__router.getResponse(request)
+            
             # return can be Deferred or Response
             if isinstance(val,Deferred):
                 val.addCallback(self.__finishRequest,request)

setup.py

@@ -63,7 +63,7 @@ def read(fname):
 
 setup(
     name="CorePost",
-    version="0.0.7",
+    version="0.0.8",
     author="Jacek Furmankiewicz",
     author_email="jacekeadE99@gmail.com",
     description=("A Twisted Web REST micro-framework"),
@@ -88,6 +88,7 @@ setup(
          'freshen>=0.2',
          'formencode>=1.2.4',
          'pyyaml>=3.1.0',
+         'jinja2>=2.6'
     ],
       
 )