newforms-admin: Initial implementation of FormSet.

git-svn-id: http://code.djangoproject.com/svn/django/branches/newforms-admin@4836 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 154 insertions, 0 deletions

diff --git a/django/newforms/formsets.py b/django/newforms/formsets.py
new file mode 100644
index 0000000000..c2649640a0
--- /dev/null
+++ b/django/newforms/formsets.py
@@ -0,0 +1,154 @@
+from django import newforms as forms
+
+# special field names
+FORM_COUNT_FIELD_NAME = 'COUNT'
+ORDERING_FIELD_NAME = 'ORDER'
+DELETION_FIELD_NAME = 'DELETE'
+
+class ManagementForm(forms.Form):
+    """
+    ``ManagementForm`` is used to keep track of how many form instances
+    are displayed on the page. If adding new forms via javascript, you should
+    increment the count field of this form as well.
+    """
+    def __init__(self, *args, **kwargs):
+        self.base_fields[FORM_COUNT_FIELD_NAME] = forms.IntegerField(widget=forms.HiddenInput)
+        super(ManagementForm, self).__init__(*args, **kwargs)
+
+class FormSet(object):
+    """A collection of instances of the same Form class."""
+
+    def __init__(self, form_class, data=None, auto_id='id_%s', prefix=None, initial=None):
+        self.form_class = form_class
+        self.prefix = prefix or 'form'
+        self.auto_id = auto_id
+        # initialization is different depending on whether we recieved data, initial, or nothing
+        if data:
+            self.management_form = ManagementForm(data, auto_id=self.auto_id, prefix=self.prefix)
+            if self.management_form.is_valid():
+                form_count = self.management_form.clean_data[FORM_COUNT_FIELD_NAME]
+            else:
+                # not sure that ValidationError is the best thing to raise here
+                raise forms.ValidationError('ManagementForm data is missing or has been tampered with')
+            self.form_list = self._forms_for_data(data, form_count=form_count)
+        elif initial:
+            form_count = len(initial)
+            self.management_form = ManagementForm(initial={FORM_COUNT_FIELD_NAME: form_count+1}, auto_id=self.auto_id, prefix=self.prefix)
+            self.form_list = self._forms_for_initial(initial, form_count=form_count)
+        else:
+            self.management_form = ManagementForm(initial={FORM_COUNT_FIELD_NAME: 1}, auto_id=self.auto_id, prefix=self.prefix)
+            self.form_list = self._empty_forms(form_count=1)
+
+    # TODO: initialization needs some cleanup and some restructuring
+    # TODO: allow more than 1 extra blank form to be displayed
+
+    def _forms_for_data(self, data, form_count):
+        form_list = []
+        for i in range(0, form_count-1):
+            form_instance = self.form_class(data, auto_id=self.auto_id, prefix=self.add_prefix(i))
+            self.add_fields(form_instance, i)
+            form_list.append(form_instance)
+        # hackish, but if the last form stayed empty, replace it with a 
+        # blank one. no 'data' or 'initial' arguments
+        form_instance = self.form_class(data, auto_id=self.auto_id, prefix=self.add_prefix(form_count-1))
+        if form_instance.is_empty():
+            form_instance = self.form_class(auto_id=self.auto_id, prefix=self.add_prefix(form_count-1))
+        self.add_fields(form_instance, form_count-1)
+        form_list.append(form_instance)
+        return form_list
+
+    def _forms_for_initial(self, initial, form_count):
+        form_list = []
+        # generate a form for each item in initial, plus one empty one
+        for i in range(0, form_count):
+            form_instance = self.form_class(initial=initial[i], auto_id=self.auto_id, prefix=self.add_prefix(i))
+            self.add_fields(form_instance, i)
+            form_list.append(form_instance)
+        # add 1 empty form
+        form_instance = self.form_class(auto_id=self.auto_id, prefix=self.add_prefix(i+1))
+        self.add_fields(form_instance, i+1)
+        form_list.append(form_instance)
+        return form_list
+
+    def _empty_forms(self, form_count):
+        form_list = []
+        # we only need one form, there's no inital data and no post data
+        form_instance = self.form_class(auto_id=self.auto_id, prefix=self.add_prefix(0))
+        form_list.append(form_instance)
+        return form_list
+
+    def get_forms(self):
+        return self.form_list
+
+    def add_fields(self, form, index):
+        """A hook for adding extra fields on to each form instance."""
+        pass
+
+    def add_prefix(self, index):
+        return '%s-%s' % (self.prefix, index)
+
+    def _get_clean_data(self):
+        return self.get_clean_data()
+
+    def get_clean_data(self):
+        clean_data_list = []
+        for form in self.get_non_empty_forms():
+            clean_data_list.append(form.clean_data)
+        return clean_data_list
+
+    clean_data = property(_get_clean_data)
+
+    def is_valid(self):
+        for form in self.get_non_empty_forms():
+            if not form.is_valid():
+                return False
+        return True
+
+    def get_non_empty_forms(self):
+        """Return all forms that aren't empty."""
+        return [form for form in self.form_list if not form.is_empty()]
+
+class FormSetWithDeletion(FormSet):
+    """A ``FormSet`` that handles deletion of forms."""
+
+    def add_fields(self, form, index):
+        """Add a delete checkbox to each form."""
+        form.fields[DELETION_FIELD_NAME] = forms.BooleanField(label='Delete', required=False)
+
+    def get_clean_data(self):
+        self.deleted_data = []
+        clean_data_list = []
+        for form in self.get_non_empty_forms():
+            if form.clean_data[DELETION_FIELD_NAME]:
+                # stick data marked for deletetion in self.deleted_data
+                self.deleted_data.append(form.clean_data)
+            else:
+               clean_data_list.append(form.clean_data)
+        return clean_data_list
+
+class FormSetWithOrdering(FormSet):
+    """A ``FormSet`` that handles re-ordering of forms."""
+
+    def get_non_empty_forms(self):
+        return [form for form in self.form_list if not form.is_empty(exceptions=[ORDERING_FIELD_NAME])]
+
+    def add_fields(self, form, index):
+        """Add an ordering field to each form."""
+        form.fields[ORDERING_FIELD_NAME] = forms.IntegerField(label='Order', initial=index+1)
+
+    def get_clean_data(self):
+        clean_data_list = []
+        for form in self.get_non_empty_forms():
+            clean_data_list.append(form.clean_data)
+        # sort clean_data by the 'ORDER' field
+        clean_data_list.sort(lambda x,y: x[ORDERING_FIELD_NAME] - y[ORDERING_FIELD_NAME])
+        return clean_data_list
+
+    def is_valid(self):
+        for form in self.get_non_empty_forms():
+            if not form.is_valid():
+                return False
+        return True
+
+# TODO: handle deletion and ordering in the same FormSet
+# TODO: model integration: form_for_instance and form_for_model type functions