dc137d705e
Fix bug related to `order` and default route introduced in https://github.com/grafana/oncall/pull/2572
69 lines
3.1 KiB
Python
69 lines
3.1 KiB
Python
from rest_framework import serializers
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from common.api_helpers.exceptions import BadRequest
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class OrderedModelSerializer(serializers.ModelSerializer):
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"""Ordered model serializer to be used in public API."""
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position = serializers.IntegerField(required=False, source="order")
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# manual_order=True is intended for use by Terraform provider only, and is not a documented feature.
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manual_order = serializers.BooleanField(default=False, write_only=True)
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class Meta:
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fields = ["position", "manual_order"]
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def create(self, validated_data):
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# Remove "manual_order" and "order" fields from validated_data, so they are not passed to create method.
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manual_order = validated_data.pop("manual_order", False)
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order = validated_data.pop("order", None)
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# Create the instance.
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# Instances are always created at the end of the list, and then moved to the desired position by _adjust_order.
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instance = super().create(validated_data)
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# Adjust order of the instance if necessary.
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if order is not None:
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self._adjust_order(instance, manual_order, order, created=True)
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return instance
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def update(self, instance, validated_data):
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# Remove "manual_order" and "order" fields from validated_data, so they are not passed to update method.
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manual_order = validated_data.pop("manual_order", False)
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order = validated_data.pop("order", None)
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# Adjust order of the instance if necessary.
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if order is not None:
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self._adjust_order(instance, manual_order, order, created=False)
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# Proceed with the update.
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return super().update(instance, validated_data)
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@staticmethod
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def _adjust_order(instance, manual_order, order, created):
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# Passing order=-1 means that the policy should be moved to the end of the list.
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# Works only for public API but not for Terraform provider.
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if order == -1 and not manual_order:
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if created:
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# The policy was just created, so it is already at the end of the list.
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return
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order = instance.max_order()
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# max_order() can't be None here because at least one instance exists – the one we are moving.
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assert order is not None
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# Check the order is in the valid range.
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# https://docs.djangoproject.com/en/4.1/ref/models/fields/#positiveintegerfield
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if order < 0 or order > 2147483647:
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raise BadRequest(detail="Invalid value for position field")
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# Orders are swapped instead of moved when using Terraform, because Terraform may issue concurrent requests
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# to create / update / delete multiple policies. "Move to" operation is not deterministic in this case, and
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# final order of policies may be different depending on the order in which requests are processed. On the other
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# hand, the result of concurrent "swap" operations is deterministic and does not depend on the order in
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# which requests are processed.
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if manual_order:
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instance.swap(order)
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else:
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instance.to(order)
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