Question

我需要以多种形式使用相同的自定义验证。在其他框架中，我将创建一个新的“Validator”类，但我不确定Django / Python的最佳选择。

以下是我所做的，是否有更好的方法（下面的解决方案）？

以任何形式：

    def clean_image(self):
        image = self.cleaned_data.get("image")

        return validate_image_with_dimensions(
            image,
            expected_width=965,
            expected_height=142
        )

在验证模块中

def validate_image_with_dimensions(image, expected_width, expected_height):
    from django.core.files.images import get_image_dimensions

    # the validation code...

    return image

以下是解决方案：

以形式：

    image = forms.ImageField(
        max_length=250,
        label=mark_safe('Image<br /><small>(must be 1100 x 316px)</small>'),
        required=True,
        validators=[
            ImageDimensionsValidator(
                expected_width=1100,
                expected_height=316
            )
        ]
    )

在验证模块中：

class ImageDimensionsValidator(object):

    def __init__(self, expected_width, expected_height):
        self.expected_width = expected_width
        self.expected_height = expected_height

    def __call__(self, image):
        """
        Validates that the image entered have the good dimensions
        """
        from django.core.files.images import get_image_dimensions

        if not image:
            pass
        else:
            width, height = get_image_dimensions(image)
            if width != self.expected_width or height != self.expected_height:
                raise ValidationError(
                    "The image dimensions are: " + str(width) + "x" + str(height) + ". "
                    "It's supposed to be " + str(self.expected_width) + "x" + str(self.expected_height)
                )

Answer 1

表单和模型字段accept a list of validators：

class YourForm(forms.Form):
   ...
   image = forms.ImageField(validators=[validate_image_with_dimensions])

验证器是任何类型的可调用对象，随意编写可调用类（django内部验证器是基于类的）。

要获得灵感，请查看django.core.validators source。

如何在Django中重用自定义验证？

1 个答案: