django.db.models.fields.files.ImageField

class documentation

class ImageField(FileField):

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Undocumented

Method __init__ Undocumented
Method ​_check​_image​_library​_installed Undocumented
Method check Undocumented
Method contribute​_to​_class Register the field with the model class it belongs to.
Method deconstruct Return enough information to recreate the field as a 4-tuple:
Method formfield Return a django.forms.Field instance for this field.
Method update​_dimension​_fields Update field's width and height fields, if defined.
Class Variable description Undocumented
Instance Variable height​_field Undocumented
Instance Variable width​_field Undocumented

Inherited from FileField:

Method ​_check​_primary​_key Undocumented
Method ​_check​_upload​_to Undocumented
Method generate​_filename No summary
Method get​_internal​_type Undocumented
Method get​_prep​_value Perform preliminary non-db specific value checks and conversions.
Method pre​_save Return field's value just before saving.
Method save​_form​_data Undocumented
Instance Variable ​_primary​_key​_set​_explicitly Undocumented
Instance Variable ​_storage​_callable Undocumented
Instance Variable storage Undocumented
Instance Variable upload​_to Undocumented

Inherited from Field (via FileField):

Class Method ​_choices​_is​_value Undocumented
Method __copy__ Undocumented
Method __deepcopy__ Undocumented
Method __eq__ Undocumented
Method __hash__ Undocumented
Method __lt__ Undocumented
Method __reduce__ Pickling should return the model._meta.fields instance of the field, not a new copy of that field. So, use the app registry to load the model and then the field back.
Method __repr__ Display the module, class, and name of the field.
Method __str__ Return "app_label.model_label.field_name" for fields attached to models.
Method ​_check​_backend​_specific​_checks Undocumented
Method ​_check​_choices Undocumented
Method ​_check​_db​_index Undocumented
Method ​_check​_deprecation​_details Undocumented
Method ​_check​_field​_name Check if field name is valid, i.e. 1) does not end with an underscore, 2) does not contain "__" and 3) is not "pk".
Method ​_check​_null​_allowed​_for​_primary​_keys Undocumented
Method ​_check​_validators Undocumented
Method ​_description Undocumented
Method ​_get​_flatchoices Flattened version of choices tuple.
Method cast​_db​_type Return the data type to use in the Cast() function.
Method clean Convert the value's type and run validation. Validation errors from to_python() and validate() are propagated. Return the correct value if no error is raised.
Method clone Uses deconstruct() to clone a new copy of this Field. Will not preserve any class attachments/attribute names.
Method db​_check Return the database column check constraint for this field, for the provided connection. Works the same way as db_type() for the case that get_internal_type() does not map to a preexisting model field.
Method db​_parameters Extension of db_type(), providing a range of different return values (type, checks). This will look at db_type(), allowing custom model fields to override it.
Method db​_type Return the database column data type for this field, for the provided connection.
Method db​_type​_parameters Undocumented
Method db​_type​_suffix Undocumented
Method get​_attname Undocumented
Method get​_attname​_column Undocumented
Method get​_choices Return choices with a default blank choices included, for use as <select> choices for this field.
Method get​_col Undocumented
Method get​_db​_converters Undocumented
Method get​_db​_prep​_save Return field's value prepared for saving into a database.
Method get​_db​_prep​_value Return field's value prepared for interacting with the database backend.
Method get​_default Return the default value for this field.
Method get​_filter​_kwargs​_for​_object Return a dict that when passed as kwargs to self.model.filter(), would yield all instances having the same value for this field as obj has.
Method get​_pk​_value​_on​_save No summary
Method has​_default Return a boolean of whether this field has a default value.
Method rel​_db​_type Return the data type that a related field pointing to this field should use. For example, this method is called by ForeignKey and OneToOneField to determine its data type.
Method run​_validators Undocumented
Method select​_format Custom format for select clauses. For example, GIS columns need to be selected as AsText(table.col) on MySQL as the table.col data can't be used by Django.
Method set​_attributes​_from​_name Undocumented
Method to​_python Convert the input value into the expected Python data type, raising django.core.exceptions.ValidationError if the data can't be converted. Return the converted value. Subclasses should override this.
Method validate Validate value and raise ValidationError if necessary. Subclasses should override this to provide validation logic.
Method value​_from​_object Return the value of this field in the given model instance.
Method value​_to​_string Return a string value of this field from the passed obj. This is used by the serialization framework.
Class Variable auto​_creation​_counter Undocumented
Class Variable default​_error​_messages Undocumented
Class Variable default​_validators Undocumented
Class Variable empty​_strings​_allowed Undocumented
Class Variable empty​_values Undocumented
Class Variable flatchoices Undocumented
Class Variable hidden Undocumented
Class Variable many​_to​_many Undocumented
Class Variable many​_to​_one Undocumented
Class Variable one​_to​_many Undocumented
Class Variable one​_to​_one Undocumented
Class Variable related​_model Undocumented
Class Variable system​_check​_deprecated​_details Undocumented
Class Variable system​_check​_removed​_details Undocumented
Instance Variable ​_db​_tablespace Undocumented
Instance Variable ​_error​_messages Undocumented
Instance Variable ​_unique Undocumented
Instance Variable ​_validators Undocumented
Instance Variable ​_verbose​_name Undocumented
Instance Variable attname Undocumented
Instance Variable auto​_created Undocumented
Instance Variable blank Undocumented
Instance Variable choices Undocumented
Instance Variable column Undocumented
Instance Variable concrete Undocumented
Instance Variable creation​_counter Undocumented
Instance Variable db​_column Undocumented
Instance Variable db​_index Undocumented
Instance Variable default Undocumented
Instance Variable editable Undocumented
Instance Variable error​_messages Undocumented
Instance Variable help​_text Undocumented
Instance Variable is​_relation Undocumented
Instance Variable max​_length Undocumented
Instance Variable model Undocumented
Instance Variable name Undocumented
Instance Variable null Undocumented
Instance Variable primary​_key Undocumented
Instance Variable remote​_field Undocumented
Instance Variable serialize Undocumented
Instance Variable unique​_for​_date Undocumented
Instance Variable unique​_for​_month Undocumented
Instance Variable unique​_for​_year Undocumented
Instance Variable verbose​_name Undocumented
Property ​_get​_default Undocumented
Property cached​_col Undocumented
Property db​_returning Private API intended only to be used by Django itself. Currently only the PostgreSQL backend supports returning multiple fields on a model.
Property db​_tablespace Undocumented
Property unique Undocumented
Property validators Some validators can't be created at field initialization time. This method provides a way to delay their creation until required.

Inherited from RegisterLookupMixin (via FileField, Field):

Class Method get​_lookups Undocumented
Class Method register​_lookup Undocumented
Static Method merge​_dicts Merge dicts in reverse to preference the order of the original list. e.g., merge_dicts([a, b]) will preference the keys in 'a' over those in 'b'.
Class Method ​_clear​_cached​_lookups Undocumented
Class Method ​_get​_lookup Undocumented
Class Method ​_unregister​_lookup Remove given lookup from cls lookups. For use in tests only as it's not thread-safe.
Method get​_lookup Undocumented
Method get​_transform Undocumented
def __init__(self, verbose_name=None, name=None, width_field=None, height_field=None, **kwargs):
overrides django.db.models.fields.files.FileField.__init__

Undocumented

def _check_image_library_installed(self):

Undocumented

def check(self, **kwargs):
overrides django.db.models.fields.files.FileField.check

Undocumented

def contribute_to_class(self, cls, name, **kwargs):
overrides django.db.models.fields.files.FileField.contribute_to_class

Register the field with the model class it belongs to.

If private_only is True, create a separate instance of this field for every subclass of cls, even if cls is not an abstract model.

def deconstruct(self):
overrides django.db.models.fields.files.FileField.deconstruct

Return enough information to recreate the field as a 4-tuple:

  • The name of the field on the model, if contribute_to_class() has been run.
  • The import path of the field, including the class, e.g. django.db.models.IntegerField. This should be the most portable version, so less specific may be better.
  • A list of positional arguments.
  • A dict of keyword arguments.

Note that the positional or keyword arguments must contain values of the following types (including inner values of collection types):

  • None, bool, str, int, float, complex, set, frozenset, list, tuple, dict
  • UUID
  • datetime.datetime (naive), datetime.date
  • top-level classes, top-level functions - will be referenced by their full import path
  • Storage instances - these have their own deconstruct() method

This is because the values here must be serialized into a text format (possibly new Python code, possibly JSON) and these are the only types with encoding handlers defined.

There's no need to return the exact way the field was instantiated this time, just ensure that the resulting field is the same - prefer keyword arguments over positional ones, and omit parameters with their default values.

def formfield(self, **kwargs):
overrides django.db.models.fields.files.FileField.formfield
Return a django.forms.Field instance for this field.
def update_dimension_fields(self, instance, force=False, *args, **kwargs):

Update field's width and height fields, if defined.

This method is hooked up to model's post_init signal to update dimensions after instantiating a model instance. However, dimensions won't be updated if the dimensions fields are already populated. This avoids unnecessary recalculation when loading an object from the database.

Dimensions can be forced to update with force=True, which is how ImageFileDescriptor.__set__ calls this method.

description =
overrides django.db.models.fields.files.FileField.description

Undocumented

height_field =

Undocumented

width_field =

Undocumented