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1 """ |
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2 YAML serializer. |
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3 |
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4 Requires PyYaml (http://pyyaml.org/), but that's checked for in __init__. |
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5 """ |
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6 |
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7 from django.db import models |
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8 from django.core.serializers.python import Serializer as PythonSerializer |
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9 from django.core.serializers.python import Deserializer as PythonDeserializer |
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10 try: |
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11 from cStringIO import StringIO |
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12 except ImportError: |
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13 from StringIO import StringIO |
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14 import yaml |
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15 |
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16 class Serializer(PythonSerializer): |
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17 """ |
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18 Convert a queryset to YAML. |
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19 """ |
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20 |
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21 internal_use_only = False |
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22 |
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23 def handle_field(self, obj, field): |
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24 # A nasty special case: base YAML doesn't support serialization of time |
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25 # types (as opposed to dates or datetimes, which it does support). Since |
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26 # we want to use the "safe" serializer for better interoperability, we |
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27 # need to do something with those pesky times. Converting 'em to strings |
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28 # isn't perfect, but it's better than a "!!python/time" type which would |
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29 # halt deserialization under any other language. |
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30 if isinstance(field, models.TimeField) and getattr(obj, field.name) is not None: |
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31 self._current[field.name] = str(getattr(obj, field.name)) |
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32 else: |
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33 super(Serializer, self).handle_field(obj, field) |
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34 |
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35 def end_serialization(self): |
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36 self.options.pop('stream', None) |
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37 self.options.pop('fields', None) |
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38 yaml.safe_dump(self.objects, self.stream, **self.options) |
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39 |
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40 def getvalue(self): |
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41 return self.stream.getvalue() |
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42 |
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43 def Deserializer(stream_or_string, **options): |
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44 """ |
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45 Deserialize a stream or string of YAML data. |
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46 """ |
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47 if isinstance(stream_or_string, basestring): |
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48 stream = StringIO(stream_or_string) |
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49 else: |
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50 stream = stream_or_string |
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51 for obj in PythonDeserializer(yaml.load(stream)): |
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52 yield obj |
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53 |