Class TextField

django/db/models/fields/__init__.py:2524–2598

class TextField(Field):
    description = _("Text")

    def __init__(self, *args, db_collation=None, **kwargs):
        super().__init__(*args, **kwargs)
        self.db_collation = db_collation

    def check(self, **kwargs):
        databases = kwargs.get("databases") or []
        return [
            *super().check(**kwargs),
            *self._check_db_collation(databases),
        ]

    def _check_db_collation(self, databases):
        errors = []
        for db in databases:
            if not router.allow_migrate_model(db, self.model):
                continue
            connection = connections[db]
            if not (
                self.db_collation is None
                or "supports_collation_on_textfield"
                in self.model._meta.required_db_features
                or connection.features.supports_collation_on_textfield
            ):
                errors.append(
                    checks.Error(
                        "%s does not support a database collation on "
                        "TextFields." % connection.display_name,
                        obj=self,
                        id="fields.E190",
                    ),
                )
        return errors

    def db_parameters(self, connection):
        db_params = super().db_parameters(connection)
        db_params["collation"] = self.db_collation
        return db_params

    def get_internal_type(self):
        return "TextField"

    def to_python(self, value):
        if isinstance(value, str) or value is None:
            return value
        return str(value)

    def get_prep_value(self, value):
        value = super().get_prep_value(value)
        return self.to_python(value)

    def formfield(self, **kwargs):
        # Passing max_length to forms.CharField means that the value's length
        # will be validated twice. This is considered acceptable since we want
        # the value in the form field (to pass into widget for example).
        return super().formfield(