dj_extras

A collection of stuff that gets re-used in a few django projects. The features in the files are described below.

utils.py

Some helper functions used to access models and responses

get_or_none

Gets the model you specify or returns none if it doesn't exist. Calls objects.get but returns None on model.DoesNotExist.

def get_or_none(model, **kwargs):

get_or_create_or_update

If a model matching key_dict for model_class exists then update it with values dict otherwise if it doesn't exist then create it used the defaults from values dict

 def get_or_create_or_update(model_class, key_dict,
                                          values_dict):

update_model_from_dict

Update a model instance's fieled from the specified dictionary. Note: This does not save the model.

 def update_model_from_dict(instance, d):

forms.py

Some Fields and other helpers for making forms

Widgets

A few widgets which work more directly with Html5 input types

PositiveNumberWidget

Uses Html5 type number and sets min to 0 if it is not already set.

PercentageWidget

Uses Html5 type number and sets min and max to 0 and 100.

RatingSliderWidget

Uses Html5 type range (usually a slider in the UI). If no min and max values are set they will also be 0 and 100.

Fields

A few custom fields for HTML5 controls

PercentageField

Based on django's FloatField it sets min and max to 0 and 100 respectively. Also the default widget is set to PercentageWidget.

SliderField

Also based on FloatField but in this case defaults to RatingSliderWidget.

Helpers

custom_formfield_callback

This can be used with a model form to control which form fields get used for each kind of model field.

 class MyClassModelForm(forms.ModelForm):
      formfield_callback = custom_formfield_callback
      class Meta:
          model = MyClass
          # etc

When this is used a models defined as percentage fields as in (dj_extras.models.PercentageField) will be assigned a field of dj_extras.forms.Percentage field. In addition ordinary PositiveIntegerField fields which have min and max will be assiged the PositiveNumberWidget.

get_form_class_for_class

A helper function for creating a model form class for a model on-the-fly. This is used with models (usually part of an inheritance hierarchy) which define a function get_editable_fields which returns an iterable of the field names which should be placed in the form.

Parameter Lists

A few helper functions which allow the creation of on-the-fly forms and formfields based on a list of parameters. The parameter types are defined by the enum ParameterTypes so that ParameterTypes.INTEGER is an int ParameterTypes.STRING is a string etc.

create_form_field_with_parameter(pdict)

Essentially a case statment which returns a django form field based on the give parameter specified as a dict with keys:

• display - the ui name for this field
• name - the actually field name
• kind - the parameter enum value Ex. ParameterTypes.BOOLEAN

A suitable django formfield object such as forms.BooleanField(label=pdict('display')) is returned.

create_form_class_with_parameter_list(plist, name)

Create a class for a form using the list of parameter descriptions given. You can optionally give it a name as well.

create_form_with_parameter_list(plist, name, initial_dict)

Like create_form_class_with_parameter_list but will create the actual form and assign values based on intial dict.

mysql_utils.py

This file includes a couple functions which use the process module and mysql/mysqldump to create mysql backups of tables in the db. The filename will be app_name.sql.gz

Create a zipped dump file of the tables in an app.

dump_mysql_db(app_name,
 				tables = None,
 				dump_path = None)

Load a zipped mysqldump file into the database

load_mysql_db(app_name, dump_path = None):

License

MIT , see the LICENSE file for details.