Model field and form field

GalleryField

class galleryfield.fields.GalleryField(target_model=None, *args, **kwargs)

Bases: JSONField

This is a model field which saves the id of images.

Parameters:

target_model (str, optional.) – A string in the form of "app_label.model_name", which can be loaded by django.apps.get_model() (see Django docs), defaults to None. If None, galleryfield.BuiltInGalleryImage will be used. If set, it should be a valid image model.

GalleryField and GalleryImages

class galleryfield.fields.GalleryImages

When you access a GalleryField on a model, you are given an instance of GalleryImages as a proxy for accessing the underlying images. Basically, a GalleryImages instance is a list of pk of the image model instances defined by target_model. That means we can manipulate the field value with method such as slice, append() and extend().

For example:

>>> g = Demogallery.objects.first()
>>> g.images
[2, 1, 3]
>>> len(g.images)
3
>>> g.images.append(4)  # assuming there is BuiltInGalleryImage with pk=4
>>> g.save()
>>> g.images
>>> [2, 1, 3, 4]

Besides that, GalleryField includes an objects attribute:

GalleryImages.objects

An queryset of image instances.

That means we can do chained query to the attribute. Sample usage:

>>> g.images.objects.all()
<QuerySet [<BuiltInGalleryImage: BuiltInGalleryImage object (2)>, <BuiltInGalleryImage:
BuiltInGalleryImage object (1)>, <BuiltInGalleryImage: BuiltInGalleryImage object (3)>,
<BuiltInGalleryImage: BuiltInGalleryImage object (4)>]>
>>> g.images.objects.filter(pk__lte=2)
<QuerySet [<BuiltInGalleryImage: BuiltInGalleryImage object (2)>, <BuiltInGalleryImage:
BuiltInGalleryImage object (1)>]>
>>> g.images.objects.filter(pk__gte=5)
<QuerySet []>

With the objects attribute, it’s also handy to render images contained in the field. For example, we can use following snippet in the template to detailed view of demo.models.DemoGallery instances:

{% for obj in object.images.objects.all %}
  <a href="{{ obj.image.url }}">
  </a>
{% endfor %}

where object in the first line is an instance of demo.models.DemoGallery.

GalleryFormField

class galleryfield.fields.GalleryFormField(max_number_of_images=None, **kwargs)

Bases: JSONField

The default formfield for galleryfield.fields.GalleryField.

Parameters:

• max_number_of_images (int, optional.) – Max allowed number of images, defaults to None, which means unlimited.

• kwargs –

  Besides the options from parent class, the following were added:

  • target_model: str, a valid target image model which can be loaded by apps.get_model. When this field is used in the model form, it is auto configured by the model instance.

    However, if this field is used as a non-model form field, when not specified, it will use the built-in default target image model galleryfield.BuiltInGalleryImage.

  • widget: if not specified, defaults to GalleryWidget with default values.

Note

If target_model not specified when initializing, an info will be logged to the stdout, which can be turned off by adding gallery_form_field.I001 in settings.SILENCED_SYSTEM_CHECKS.

Note

galleryfield.fields.GalleryFormField is not supposed to be used independently (i.e., as a non-modelform field). The most possible cases for us to access the formfield are in the modelform configurations. For example:

class MyGalleryForm(forms.ModelForm):
    class Meta:
        model = MyGallery
        fields = ["images"]

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.fields["images"].required = False
        self.fields["images"].max_number_of_images = 2

        # from django.forms.widgets import Textarea
        # self.fields["images"].widget = Textarea()  # Use Textarea as widget

Warning

If you want to use galleryfield.fields.GalleryFormField as a non-modelform field, remember to initialize the field with a key word argument like target_model="my_app.MyImage", otherwise it will use galleryfield.BuiltInGalleryImage as the target_model. Also, keep in mind that the cleaned_data of the field only contains the pk of the image model instances.