Changes between Initial Version and Version 1 of CookBookManipulatorCustomManipulator

Timestamp:

Jan 18, 2006, 7:11:44 PM (20 years ago)

Author:

brantley

Comment:

--

CookBookManipulatorCustomManipulator

@@ +1 @@
+Using Manipulators can be annoying and confusing, use this to create simple, elegant ones:
+
+{{{
+from django.core import formfields, validators
+
+class Manipulator(formfields.Manipulator):
+    default = {}
+    done = False
+    
+    def getData(self, request):
+        return request.POST
+    
+    def getForm(self, data, errors):
+        return formfields.FormWrapper(self, data, errors)
+    
+    def process(self, request):
+        data = self.getData(request)
+        if data:
+            new_data = data.copy()
+            errors = self.get_validation_errors(new_data)
+            if not errors:
+                self.do_html2python(new_data)
+                
+                self.done = True
+                return self.complete(request, new_data)                
+        else:
+            errors = {}
+            new_data = self.default
+        self.form = self.getForm(new_data, errors)
+        return self.form
+
+    def complete(self, request, data):
+        pass
+}}}
+
+Now to use, subclass it, and fill in the necessary methods ("__init__" and "complete"), also give it the fields:
+
+{{{
+class PollEdit(Manipulator):
+    fields = (
+        formfields.TextField("title", maxlength=32, is_required=True),
+        formfields.TextField("question", maxlength=128, is_required=True),
+    )
+        
+    def __init__(self, poll):
+        # You can also define your fields here, if you'd like.
+        self.poll = poll
+        
+    def complete(self, request, data):
+        self.poll.title = data['title']
+        self.poll.question = data['question']
+        self.poll.save()
+
+}}}
+
+Usage of the final Manipulator is quite simple:
+
+{{{
+def edit_poll(request, id):
+    poll = polls.get_object(pk=id)      #Assume it works
+    manipulator = PollEdit(poll)
+    form = manipulator.process(request)    #Process returns a form if it's needed
+    if (form):
+         return render_to_response('polls/edit_form', {'form': form})
+    else:
+         return HttpResponseRedirect("/polls/" % poll.id)
+}}}
+
+Here's a custom Add Manipulator:
+
+{{{
+class PollAdd(Manipulator):
+    fields = (
+        formfields.TextField("title", maxlength=32, is_required=True),
+        formfields.TextField("question", maxlength=128, is_required=True),
+    )
+        
+    def __init__(self):
+        self.default = {'title': "Unnamed", 'question': 'Insert your question here.'}
+        #This sets your default values.
+    
+    def complete(self, request, data):
+        poll = polls.Poll(title=data['title'], question=data['question'])
+        poll.save()
+        return poll
+
+}}}
+
+And here's the add usage:
+
+{{{
+def add_poll(request):
+    manipulator = PollAdd()
+    result = manipulator.process(request)
+    if (manipulator.done): #Are we done processing?
+         return HttpResponseRedirect("/polls/" % result.id)
+    else: #Otherwise, place the form.
+         return render_to_response('polls/new_form', {'form': manipulator.form})
+}}}
+