Fixed #8164 -- Fields on a ModelForm are now ordered in the order specified in the fields attribute of the ModelForm's Meta class. Thanks to Alex Gaynor for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10062 bcc190cf-cafb-0310-a4f2-bffc1f526a37

3 files changed, 65 insertions, 14 deletions

diff --git a/django/forms/models.py b/django/forms/models.py
index bfc0b35803..595b775f4f 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -149,7 +149,6 @@ def fields_for_model(model, fields=None, exclude=None, formfield_callback=lambda
     fields will be excluded from the returned fields, even if they are listed
     in the ``fields`` argument.
     """
-    # TODO: if fields is provided, it would be nice to return fields in that order
     field_list = []
     opts = model._meta
     for f in opts.fields + opts.many_to_many:
@@ -162,7 +161,10 @@ def fields_for_model(model, fields=None, exclude=None, formfield_callback=lambda
         formfield = formfield_callback(f)
         if formfield:
             field_list.append((f.name, formfield))
-    return SortedDict(field_list)
+    field_dict = SortedDict(field_list)
+    if fields:
+        field_dict = SortedDict([(f, field_dict[f]) for f in fields if (not exclude) or (exclude and f not in exclude)])
+    return field_dict
 
 class ModelFormOptions(object):
     def __init__(self, options=None):
diff --git a/docs/topics/forms/modelforms.txt b/docs/topics/forms/modelforms.txt
index 50beea2d71..f424fb9b60 100644
--- a/docs/topics/forms/modelforms.txt
+++ b/docs/topics/forms/modelforms.txt
@@ -259,7 +259,8 @@ model fields:
 
 2. Use the ``fields`` attribute of the ``ModelForm``'s inner ``Meta``
    class.  This attribute, if given, should be a list of field names
-   to include in the form.
+   to include in the form. The form will render the fields in the same
+   order they are specified in the ``fields`` attribute.
 
 3. Use the ``exclude`` attribute of the ``ModelForm``'s inner ``Meta``
    class.  This attribute, if given, should be a list of field names
@@ -336,6 +337,31 @@ parameter when declaring the form field::
    ...     class Meta:
    ...         model = Article
 
+Changing the order of fields
+----------------------------
+
+By default, a ``ModelForm`` will render fields in the same order that
+they are defined on the model, with ``ManyToManyField``s appearing last.
+If you want to change the order in which fields are rendered, you can
+use the ``fields`` attribute on the ``Meta`` class.
+
+The ``fields`` attribute defines the subset of model fields that will be
+rendered, and the order in which they will be rendered. For example given this
+model::
+
+    class Book(models.Model):
+        author = models.ForeignKey(Author)
+        title = models.CharField(max_length=100)
+
+the ``author`` field would be rendered first. If we wanted the title field
+to be rendered first, we could specify the following ``ModelForm``::
+
+    >>> class BookForm(ModelForm):
+    ...     class Meta:
+    ...         model = Book
+    ...         fields = ['title', 'author']
+
+
 Overriding the clean() method
 -----------------------------
 
diff --git a/tests/modeltests/model_forms/models.py b/tests/modeltests/model_forms/models.py
index e12363cf3c..9261900bf8 100644
--- a/tests/modeltests/model_forms/models.py
+++ b/tests/modeltests/model_forms/models.py
@@ -105,12 +105,12 @@ try:
     # If PIL is not available, ImageField tests are omitted.
     from PIL import Image, _imaging
     test_images = True
-    
+
     class ImageFile(models.Model):
         def custom_upload_path(self, filename):
             path = self.path or 'tests'
             return '%s/%s' % (path, filename)
-    
+
         description = models.CharField(max_length=20)
         image = models.ImageField(storage=temp_storage, upload_to=custom_upload_path,
                                   width_field='width', height_field='height')
@@ -120,15 +120,15 @@ try:
 
         def __unicode__(self):
             return self.description
-    
+
     class OptionalImageFile(models.Model):
         def custom_upload_path(self, filename):
             path = self.path or 'tests'
             return '%s/%s' % (path, filename)
-    
+
         description = models.CharField(max_length=20)
         image = models.ImageField(storage=temp_storage, upload_to=custom_upload_path,
-                                  width_field='width', height_field='height', 
+                                  width_field='width', height_field='height',
                                   blank=True, null=True)
         width = models.IntegerField(editable=False, null=True)
         height = models.IntegerField(editable=False, null=True)
@@ -138,7 +138,7 @@ try:
             return self.description
 except ImportError:
     test_images = False
-    
+
 class CommaSeparatedInteger(models.Model):
     field = models.CommaSeparatedIntegerField(max_length=20)
 
@@ -176,16 +176,16 @@ class Book(models.Model):
     title = models.CharField(max_length=40)
     author = models.ForeignKey(Writer, blank=True, null=True)
     special_id = models.IntegerField(blank=True, null=True, unique=True)
-    
+
     class Meta:
         unique_together = ('title', 'author')
-        
+
 class ExplicitPK(models.Model):
     key = models.CharField(max_length=20, primary_key=True)
     desc = models.CharField(max_length=20, blank=True, unique=True)
     class Meta:
         unique_together = ('key', 'desc')
-    
+
     def __unicode__(self):
         return self.key
 
@@ -331,6 +331,29 @@ We can also subclass the Meta inner class to change the fields list.
 <tr><th><label for="id_slug">Slug:</label></th><td><input id="id_slug" type="text" name="slug" maxlength="20" /></td></tr>
 <tr><th><label for="id_checkbox">Checkbox:</label></th><td><input type="checkbox" name="checkbox" id="id_checkbox" /></td></tr>
 
+# test using fields to provide ordering to the fields
+>>> class CategoryForm(ModelForm):
+...     class Meta:
+...         model = Category
+...         fields = ['url', 'name']
+
+>>> CategoryForm.base_fields.keys()
+['url', 'name']
+
+
+>>> print CategoryForm()
+<tr><th><label for="id_url">The URL:</label></th><td><input id="id_url" type="text" name="url" maxlength="40" /></td></tr>
+<tr><th><label for="id_name">Name:</label></th><td><input id="id_name" type="text" name="name" maxlength="20" /></td></tr>
+
+>>> class CategoryForm(ModelForm):
+...     class Meta:
+...         model = Category
+...         fields = ['slug', 'url', 'name']
+...         exclude = ['url']
+
+>>> CategoryForm.base_fields.keys()
+['slug', 'name']
+
 # Old form_for_x tests #######################################################
 
 >>> from django.forms import ModelForm, CharField
@@ -1331,8 +1354,8 @@ False
 True
 
 # Unique & unique together with null values
->>> class BookForm(ModelForm): 
-...     class Meta: 
+>>> class BookForm(ModelForm):
+...     class Meta:
 ...        model = Book
 >>> w = Writer.objects.get(name='Mike Royko')
 >>> form = BookForm({'title': 'I May Be Wrong But I Doubt It', 'author' : w.pk})