This example shows, how to use database views with django models. NewestArticle models contains 100 newest Articles. Remember, that NewestArticle model is read-only. Tested with mysql.
Getting a new ID according to the content type.
A mixin to define permissions on models. This is more of an abstract model to subclass/customise than a plug-in solution. Explanations are [here](http://www.muhuk.com/2009/05/django-permission-system/).
This is a basic stub for a model that you can use to easily add customizable JSON serialization to your models. Make your model inherit from JsonableModel, and then define the models/yourmodel.json template with whatever information from the model that you want to make available.
Attempt to get a model from the `AppCache` and raise `Http404` if it cannot be found.
A CharField (Model) that checks that the value is a valid HTML color code (Hex triplet) like #FFEE00.
This class works in compatibility with a ModelForm, but instead of show a form, it shows the field values. The Meta class attributes can be used to customize fields to show, to be excluded, to divide by sections, to urlize text fields, etc. **Example 1:** class InfoSingleCertificate(ModelInfo): class Meta: model = SingleCertificate sections = ( (None, ('vessel','description','document','comments','status',)), ('Issue', ('issue_date','issue_authority','issue_location',)), ) **Example 2:** class InfoSingleCertificate(ModelInfo): class Meta: model = SingleCertificate fields = ('vessel','description','document','comments','status', 'issue_date','issue_authority','issue_location',) **How to use:** Just save this snippet as a file in your project, import to your views.py module (or a new module named "info.py") and create classes following seemed sytax you use for ModelForms.
This class will automatically create a django choices tuple like this: STATUS_CHOICES = django_choices(Draft=1, Public=2, Closed=3) Additionally, it includes a method that converts the choices tuple to a dictionary. Like this: STATUS = STATUS_CHOICES.to_dict() Those types can come in handy when you need to use those magic values in your code. Best done within the model once so everyone can use it. Code based on: http://www.djangosnippets.org/snippets/455/. By the way, if you want to just have the method without having to convert to the newer syntax.. it's backward compatible. Just add django_choices in front of the first paren for your choices tuple.
I had a problem: too many fetches from the DB. So, how to reduce load on the database without major changes to the code? Cache Manager is the answer. I've managed to reduce number of DB hits as much as 80% in some cases (dictionaries, complex relations). It is using standard cache mechanisms. I'm using it with mathopd. This is a very simple solution, instead of standard Manager, put this in your model definition as: `objects = CacheManager()` Then everythere elase in the code instead of all() or get(...) call all_cached() or get_cached(). I've kept original methods intact, to have an dual access, when you really, really must have frest data from the DB, and you can't wait for cache to expire. This is much easier to work with, then manually getting fetched data from the cache.No change to your existing code 9except model) and voila! Additionally if you have some data, you would like to store with your serialized object (e.g. related data, dynamic dictionaries), you can do this in the model method '_init_instance_cache'). Drop me an email if you find this useful. :)
The code was placed inside a helper file without using a class. The Django validator was not designed to work with validator classes, it would appear, so retrieving the value from the field proved to be a hassle. Just create a helper file, import it on your model, and use the validator in the standard way, as such: cnpj = models.CharField(unique=True, max_length=14, validators=[validate_CNPJ]) cpf = models.CharField(unique=True, max_length=14, validators=[validate_CPF])
See http://stackoverflow.com/questions/927729/how-to-override-the-verbose-name-of-a-superclass-model-field-in-django/24475838#24475838
Provides UUIDField for your models. This version creates very short UUID represenation (21 chars) when the record is added eg. in admin. Generated ids are safe to be used in URLs. You can put represent it in admin as 'readonly_fields=("uuid",)'
Sometimes we may need to generate a *ModelChoiceField* in which choices are generated at runtime, depending on the locale language. The snippet generates a *ChoiceField* based on a queryset and a specific attribute of the Model, ordering the choices by the attribute content in the locale language. **Usage example** (inside a form declaration) country = LazyModelChoiceField(sort_by='name', queryset = \ Country.objects.all, empty_label=_('All countries'), label=_('Country')) Based on lsbardel LazyChoiceField implementation (snippet 1767)
This management command is run like this: `./manage.py -a someapp filename.cfg` it looks in `someapp`'s directory for a file called `/config/filename.cfg` with the format explained in the help text, and creates the model instances described in the config file. It uses the configobj module. this would be an example config file: [project.Profile] [[fields]] receive_notifications = False [[children]] [[[auth.User]]] [[[[fields]]]] username = AnnonymousUser password = ! # set unusable password. There's no way yet to hash and set a given password email = [email protected]
This utility makes a text dump of a model instance, including objects related by a forward or reverse foreign key. The result is a hierarchical data structure where * each instance is represented as a list of fields, * each field as a (<name>, <value>) tuple, * each <value> as a primitive type, a related object (as a list of fields), or a list of related objects. See the docstring for examples. We used this to make text dumps of parts of the database before and after running a batch job. The format was more useful than stock `dumpdata` output since all related data is included with each object. These dumps lend themselves particularly well for comparison with a visual diff tool like [Meld](http://meldmerge.org/).