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108 lines
3.8 KiB
108 lines
3.8 KiB
""" |
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A Python "serializer". Doesn't do much serializing per se -- just converts to |
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and from basic Python data types (lists, dicts, strings, etc.). Useful as a basis for |
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other serializers. |
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""" |
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from django.conf import settings |
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from django.core.serializers import base |
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from django.db import models |
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from django.utils.encoding import smart_unicode |
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class Serializer(base.Serializer): |
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""" |
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Serializes a QuerySet to basic Python objects. |
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""" |
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internal_use_only = True |
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def start_serialization(self): |
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self._current = None |
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self.objects = [] |
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def end_serialization(self): |
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pass |
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def start_object(self, obj): |
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self._current = {} |
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def end_object(self, obj): |
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self.objects.append({ |
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"model" : smart_unicode(obj._meta), |
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"pk" : smart_unicode(obj._get_pk_val(), strings_only=True), |
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"fields" : self._current |
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}) |
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self._current = None |
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def handle_field(self, obj, field): |
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self._current[field.name] = smart_unicode(getattr(obj, field.name), strings_only=True) |
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def handle_fk_field(self, obj, field): |
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related = getattr(obj, field.name) |
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if related is not None: |
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if field.rel.field_name == related._meta.pk.name: |
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# Related to remote object via primary key |
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related = related._get_pk_val() |
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else: |
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# Related to remote object via other field |
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related = getattr(related, field.rel.field_name) |
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self._current[field.name] = smart_unicode(related, strings_only=True) |
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def handle_m2m_field(self, obj, field): |
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if field.creates_table: |
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self._current[field.name] = [smart_unicode(related._get_pk_val(), strings_only=True) |
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for related in getattr(obj, field.name).iterator()] |
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def getvalue(self): |
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return self.objects |
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def Deserializer(object_list, **options): |
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""" |
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Deserialize simple Python objects back into Django ORM instances. |
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It's expected that you pass the Python objects themselves (instead of a |
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stream or a string) to the constructor |
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""" |
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models.get_apps() |
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for d in object_list: |
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# Look up the model and starting build a dict of data for it. |
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Model = _get_model(d["model"]) |
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data = {Model._meta.pk.attname : Model._meta.pk.to_python(d["pk"])} |
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m2m_data = {} |
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# Handle each field |
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for (field_name, field_value) in d["fields"].iteritems(): |
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if isinstance(field_value, str): |
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field_value = smart_unicode(field_value, options.get("encoding", settings.DEFAULT_CHARSET), strings_only=True) |
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field = Model._meta.get_field(field_name) |
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# Handle M2M relations |
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if field.rel and isinstance(field.rel, models.ManyToManyRel): |
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m2m_convert = field.rel.to._meta.pk.to_python |
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m2m_data[field.name] = [m2m_convert(smart_unicode(pk)) for pk in field_value] |
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# Handle FK fields |
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elif field.rel and isinstance(field.rel, models.ManyToOneRel): |
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if field_value is not None: |
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data[field.attname] = field.rel.to._meta.get_field(field.rel.field_name).to_python(field_value) |
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else: |
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data[field.attname] = None |
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# Handle all other fields |
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else: |
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data[field.name] = field.to_python(field_value) |
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yield base.DeserializedObject(Model(**data), m2m_data) |
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def _get_model(model_identifier): |
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""" |
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Helper to look up a model from an "app_label.module_name" string. |
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""" |
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try: |
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Model = models.get_model(*model_identifier.split(".")) |
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except TypeError: |
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Model = None |
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if Model is None: |
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raise base.DeserializationError(u"Invalid model identifier: '%s'" % model_identifier) |
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return Model
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