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| -rw-r--r-- | docs/api-guide/serializers.md | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/docs/api-guide/serializers.md b/docs/api-guide/serializers.md index 19efde3c..da1efb8f 100644 --- a/docs/api-guide/serializers.md +++ b/docs/api-guide/serializers.md @@ -110,7 +110,22 @@ Your `validate_<fieldname>` methods should either just return the `attrs` dictio ### Object-level validation -To do any other validation that requires access to multiple fields, add a method called `.validate()` to your `Serializer` subclass. This method takes a single argument, which is the `attrs` dictionary. It should raise a `ValidationError` if necessary, or just return `attrs`. +To do any other validation that requires access to multiple fields, add a method called `.validate()` to your `Serializer` subclass. This method takes a single argument, which is the `attrs` dictionary. It should raise a `ValidationError` if necessary, or just return `attrs`. For example: + + from rest_framework import serializers + + class EventSerializer(serializers.Serializer): + description = serializers.CahrField(max_length=100) + start = serializers.DateTimeField() + finish = serializers.DateTimeField() + + def validate(self, attrs): + """ + Check that the start is before the stop. + """ + if attrs['start'] < attrs['finish']: + raise serializers.ValidationError("finish must occur after start") + return attrs ## Saving object state |