From c63285f8bc0c6d57478005d458faf3b13b59329a Mon Sep 17 00:00:00 2001
From: helmutm <helmutm@fd906abe-77d9-0310-91a1-e0d9ade77398>
Date: Tue, 8 Sep 2009 07:16:49 +0000
Subject: [PATCH] work in progress: REST/JSON handling

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3543 fd906abe-77d9-0310-91a1-e0d9ade77398
---
 roa/json.py         | 49 +++++++++++++++++++++++++++++++++++----------
 roa/traversal.py    | 33 +++++++++++++++++-------------
 roa/z2/traversal.py | 17 +++++++++-------
 3 files changed, 67 insertions(+), 32 deletions(-)

diff --git a/roa/json.py b/roa/json.py
index 9e6193b..bf2544c 100644
--- a/roa/json.py
+++ b/roa/json.py
@@ -22,6 +22,7 @@ Adapter(s)/view(s) for providing object attributes and other data in JSON format
 $Id$
 """
 
+from zope.interface import implements
 from cybertools.util import json
 
 
@@ -31,19 +32,45 @@ class JSONView(object):
         self.context = context
         self.request = request
 
-    def __call__(self):
-        return self.context.__name__
-        return json.dumps(self.context.__dict__.keys())
+    # application methods, to be implemented by subclass
 
-    def create(self, name):
-        print '*** create (PUT)', self.context, name
-        return self.context
+    def getData(self, **kw):
+        return {}
 
-    def put(self):
-        print '*** PUT', self.context
-        return self.context
+    def putData(self, data):
+        return True
+
+    def createObject(self, name, data):
+        return True
+
+    # protocol methods
 
     def get(self):
         print '*** GET', self.context
-        self.request.response.write('hello')
-        return self.context
+        self.setHeader()
+        return json.dumps(self.getData())
+
+    def put(self):
+        print '*** PUT', self.context, self.getBody()
+        self.setHeader()
+        result = self.putData(self.getBody())
+        return json.dumps(dict(ok=result))
+
+    def create(self, name):
+        print '*** create (PUT)', self.context, name, self.getBody()
+        self.setHeader(201)
+        result = self.createObject(name, self.getBody())
+        return json.dumps(dict(ok=result, id=name))
+
+    # helper methods
+
+    def getBody(self):
+        inp = self.request.stdin
+        inp.seek(0)
+        return inp.read()
+
+    def setHeader(self, status=None):
+        response = self.request.response
+        if status:
+            response.setStatus(status)
+        response.setHeader('Content-Type', 'application/json')
diff --git a/roa/traversal.py b/roa/traversal.py
index f429029..e89262f 100644
--- a/roa/traversal.py
+++ b/roa/traversal.py
@@ -30,33 +30,35 @@ jsonMimeTypes = ('application/json',)
 
 
 def isJSONRequest(request):
-    return request.get('CONTENT_TYPE') in jsonMimeTypes
+    return request.get('HTTP_ACCEPT').split(';', 1)[0] in jsonMimeTypes
+    #return request.get('CONTENT_TYPE') in jsonMimeTypes
 
 
 class CheckJSONTraverser(ItemTraverser):
 
+    def getChild(self, name):
+        # may be overwritten by subclass
+        return self.context.get(name)
+
     def publishTraverse(self, request, name):
         if isJSONRequest(request):
             return self.jsonTraverse(request, name)
         return self.defaultTraverse(request, name)
 
     def jsonTraverse(self, request, name):
-        print '*** jsonTraverse', self.context, name
-        if request['TraversalRequestNameStack']:
-            return self.defaultTraverse(request, name)
         method = self.request['REQUEST_METHOD']
-        print '*** traversing', self.context, name, method
-        item = self.context.get(name)
-        if item is None:
-            view = component.getMultiAdapter((self.context, request), name='json')
-            if view is None:
-                return self.defaultTraverse(request, name)
+        child = self.getChild(name)
+        print '*** traversing', method, self.context, name, child
+        if self.getTraversalStack():
+            if child is None:
+                raise AttributeError(name)
+            return child
+        if child is None:
             if method == 'PUT':
+                view = component.getMultiAdapter((self.context, request), name='json')
                 return view.create(name)
-            return self.defaultTraverse(request, name)
-        view = component.getMultiAdapter((item, request), name='json')
-        if view is None:
-            return self.defaultTraverse(request, name)
+            raise AttributeError(name)
+        view = component.getMultiAdapter((child, request), name='json')
         if method == 'PUT':
             return view.put()
         return view.get()
@@ -68,3 +70,6 @@ class CheckJSONTraverser(ItemTraverser):
         if self.isJSONRequest(request):
             return self.context, ('@@json',)
         return super(CheckJSONTraverser, self).browserDefault(request)
+
+    def getTraversalStack(self):
+        return self.request['TraversalRequestNameStack']
diff --git a/roa/z2/traversal.py b/roa/z2/traversal.py
index 4e3bcc2..b934678 100644
--- a/roa/z2/traversal.py
+++ b/roa/z2/traversal.py
@@ -38,13 +38,16 @@ class CheckJSONTraverser(BaseTraverser, DefaultPublishTraverse):
         return DefaultPublishTraverse.browserDefault(self, request)
 
 
-old_traverse = HTTPRequest.traverse
+def install_traverse_patch():
 
-def traverse(self, *args, **kw):
-    if isJSONRequest(self):
-        self.maybe_webdav_client = 0
-    old_traverse(self, *args, **kw)
+    base_traverse = HTTPRequest.traverse
 
-HTTPRequest.traverse = traverse
+    def traverse(self, *args, **kw):
+        if isJSONRequest(self):
+            self.maybe_webdav_client = 0
+        return base_traverse(self, *args, **kw)
 
-print '***** HTTPRequest.traverse monkey patch installed.'
+    HTTPRequest.traverse = traverse
+    print '***** HTTPRequest.traverse monkey patch installed.'
+
+install_traverse_patch()