1 #!/usr/bin/python2.5

     2 #

     3 # Copyright 2008 the Melange authors.

     4 #

     5 # Licensed under the Apache License, Version 2.0 (the "License");

     6 # you may not use this file except in compliance with the License.

     7 # You may obtain a copy of the License at

     8 #

     9 #   http://www.apache.org/licenses/LICENSE-2.0

    10 #

    11 # Unless required by applicable law or agreed to in writing, software

    12 # distributed under the License is distributed on an "AS IS" BASIS,

    13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

    14 # See the License for the specific language governing permissions and

    15 # limitations under the License.

    16 

    17 """Helpers used to display various views that are forms.

    18 """

    19 

    20 __authors__ = [

    21   '"Todd Larsen" <tlarsen@google.com>',

    22   ]

    23 

    24 

    25 from google.appengine.ext.db import djangoforms

    26 

    27 

    28 class DbModelForm(djangoforms.ModelForm):

    29   """Subclass of Django ModelForm that fixes some label and help_text issues.

    30 

    31   The default behavior of ModelForm is to use the verbose_name in all

    32   lowercase, capitalizing only the first character, as the displayed field

    33   label.  This class uses verbose_name unaltered as the visible field label

    34   instead.

    35 

    36   The Property classes used by the App Engine Datastore do not have a

    37   help_text parameter to their constructor.  In a Model class, a help_text

    38   attribute *can* be added to the property after it is created, but the

    39   help text will not be automatically passed along to the Django ModelForm.

    40   This class detects the presence of a help_text attribute and adds it to

    41   the corresponding form field object.

    42 

    43   ugettext_lazy() proxies used for internationalization in the Model will

    44   still work correctly with this new behavior, as long as the original

    45   strings are used as the translation keys.

    46   """

    47 

    48   def __init__(self, *args, **kwargs):

    49     """Fixes label and help_text issues after parent initialization.

    50 

    51     Args:

    52       *args, **kwargs:  passed through to parent __init__() constructor

    53     """

    54     super(DbModelForm, self).__init__(*args, **kwargs)

    55 

    56     for field_name in self.fields.iterkeys():

    57       # Since fields can be added only to the ModelForm subclass, check to

    58       # see if the Model has a corresponding field first.

    59       if hasattr(self.Meta.model, field_name):

    60         model_prop = getattr(self.Meta.model, field_name)

    61 

    62         # Check if the Model property defined verbose_name, and copy that

    63         # verbatim to the corresponding field label.

    64         if hasattr(model_prop, 'verbose_name'):

    65           self.fields[field_name].label = model_prop.verbose_name

    66 

    67         # Check if the Model property added help_text, and copy that verbatim

    68         # to the corresponding field help_text.

    69         if hasattr(model_prop, 'help_text'):

    70           self.fields[field_name].help_text = model_prop.help_text