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from zope.proxy import isProxy
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from zope.publisher.interfaces import NotFound
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from zope.schema import ValidationError, getFields
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from zope.schema.interfaces import IDatetime, IObject
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from zope.schema.interfaces import ConstraintNotSatisfied, IChoice, IObject
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from zope.security.proxy import removeSecurityProxy
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from canonical.lazr.enum import BaseItem
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# XXX leonardr 2008-01-25 bug=185958:
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from canonical.launchpad.webapp.interfaces import ICanonicalUrlData
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from canonical.lazr.interfaces import (
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ICollection, ICollectionField, ICollectionResource, IEntry,
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IEntryResource, IHTTPResource, IJSONPublishable, IResourceGETOperation,
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IResourcePOSTOperation, IScopedCollection, IServiceRootResource)
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IEntryResource, IFieldDeserializer, IHTTPResource, IJSONPublishable,
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IResourceGETOperation, IResourcePOSTOperation, IScopedCollection,
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from canonical.launchpad.webapp.vocabulary import SQLObjectVocabularyBase
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from canonical.lazr.rest.schema import URLDereferencingMixin
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IResourcePOSTOperation)
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return len(adapters) > 0
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def toWADL(self, template_name):
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"""Represent this resource as a WADL application.
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The WADL document describes the capabilities of this resource.
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template = LazrPageTemplateFile('../templates/' + template_name)
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namespace = template.pt_getContext()
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namespace['context'] = self
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return template.pt_render(namespace)
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def getPreferredSupportedContentType(self):
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"""Of the content types we serve, which would the client prefer?
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The web service supports WADL and JSON representations. The
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default is JSON. This method determines whether the client
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would rather have WADL or JSON.
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content_types = self.getPreferredContentTypes()
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wadl_pos = content_types.index(self.WADL_TYPE)
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wadl_pos = float("infinity")
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json_pos = content_types.index(self.JSON_TYPE)
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json_pos = float("infinity")
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if wadl_pos < json_pos:
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return self.WADL_TYPE
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return self.JSON_TYPE
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def getPreferredContentTypes(self):
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"""Find which content types the client prefers to receive."""
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return self._parseAcceptStyleHeader(self.request.get('HTTP_ACCEPT'))
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def _fieldValueIsObject(self, field):
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"""Does the given field expect a data model object as its value?
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Obviously an IObject field is expected to have a data model
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object as its value. But an IChoice field might also have a
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vocabulary drawn from the set of data model objects.
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if IObject.providedBy(field):
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if IChoice.providedBy(field):
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# Find out whether the field's vocabulary is made of
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# database objects (which correspond to resources that
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# need to be linked to) or regular objects (which can
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# be serialized to JSON).
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field = field.bind(self.context)
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return isinstance(field.vocabulary, SQLObjectVocabularyBase)
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def _parseAcceptStyleHeader(self, value):
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"""Parse an HTTP header from the Accept-* family.
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data['self_link'] = canonical_url(self.context)
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for name, field in getFields(self.entry.schema).items():
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value = getattr(self.entry, name)
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if ICollectionField.providedBy(field):
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# The field is a collection; include a link to the
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# collection resource.
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if value is not None:
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key = name + '_collection_link'
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data[key] = "%s/%s" % (data['self_link'], name)
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elif IObject.providedBy(field):
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elif self._fieldValueIsObject(field):
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# The field is an entry; include a link to the
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# entry resource.
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if value is not None:
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# No custom operation was specified. Implement a standard
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# GET, which serves a JSON or WADL representation of the
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content_types = self.getPreferredContentTypes()
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wadl_pos = content_types.index(self.WADL_TYPE)
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wadl_pos = float("infinity")
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json_pos = content_types.index(self.JSON_TYPE)
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json_pos = float("infinity")
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# If the client's desire for WADL outranks its desire for
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# JSON, serve WADL. Otherwise, serve JSON.
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if wadl_pos < json_pos:
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if self.getPreferredSupportedContentType() == self.WADL_TYPE:
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result = self.toWADL().encode("utf-8")
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self.request.response.setHeader(
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'Content-Type', self.WADL_TYPE)
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validated_changeset = {}
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for repr_name, value in changeset.items():
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if repr_name == 'self_link':
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# The self link isn't part of the schema, so it's
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# handled separately.
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if value == canonical_url(self.context):
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self.request.response.setStatus(400)
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return ("You tried to modify the read-only attribute "
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if value != canonical_url(self.context):
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errors.append("self_link: You tried to modify "
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"a read-only attribute.")
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541
change_this_field = True
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# (Of course, you also can't change
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# 'foo_collection_link', but that's taken care of
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self.request.response.setStatus(400)
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return ("You tried to modify the nonexistent attribute '%s'"
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errors.append("%s: You tried to modify a nonexistent "
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"attribute." % repr_name)
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# Around this point the specific value provided by the client
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# becomes relevant, so we pre-process it if necessary.
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# becomes relevant, so we deserialize it.
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element = element.bind(self.context)
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deserializer = getMultiAdapter((element, self.request),
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value = deserializer.deserialize(value)
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except (ValueError, ValidationError), e:
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errors.append("%s: %s" % (repr_name, e))
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if (IObject.providedBy(element)
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583
and not ICollectionField.providedBy(element)):
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# 'value' is the URL to an object. Dereference the URL
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# to find the actual object.
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value = self.dereference_url(value)
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self.request.response.setStatus(400)
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return ("Your value for the attribute '%s' wasn't "
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"the URL to any object published by this web "
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"service." % repr_name)
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underlying_object = removeSecurityProxy(value)
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value = underlying_object.context
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# The URL points to an object, but is it an object of the
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# TODO leonardr 2008-15-04
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# blueprint=api-wadl-description: This should be moved
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# into the ObjectLookupFieldDeserializer, once we make
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# it possible for Vocabulary fields to specify a
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# schema class the way IObject fields can.
556
589
if not element.schema.providedBy(value):
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self.request.response.setStatus(400)
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return ("Your value for the attribute '%s' doesn't "
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"point to the right kind of object." % repr_name)
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elif IDatetime.providedBy(element):
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value = DateTimeParser().parse(value)
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(year, month, day, hours, minutes, secondsAndMicroseconds,
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seconds = int(secondsAndMicroseconds)
567
round((secondsAndMicroseconds - seconds) * 1000000))
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if timezone not in ['Z', '+0000', '-0000']:
569
self.request.response.setStatus(400)
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return ("You set the attribute '%s' to a time "
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value = datetime(year, month, day, hours, minutes,
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seconds, microseconds, pytz.utc)
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except (DateError, DateTimeError, SyntaxError):
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self.request.response.setStatus(400)
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return ("You set the attribute '%s' to a value "
578
"that doesn't look like a date." % repr_name)
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errors.append("%s: Your value points to the "
591
"wrong kind of object" % repr_name)
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# The current value of the attribute also becomes
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# relevant, so we obtain that. If the attribute designates
597
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if ICollectionField.providedBy(element):
598
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change_this_field = False
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if value != current_value:
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self.request.response.setStatus(400)
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return ("You tried to modify the collection link '%s'"
614
errors.append("%s: You tried to modify a collection "
615
"attribute." % repr_name)
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618
if element.readonly:
605
619
change_this_field = False
606
620
if value != current_value:
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self.request.response.setStatus(400)
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return ("You tried to modify the read-only attribute '%s'"
621
errors.append("%s: You tried to modify a read-only "
622
"attribute." % repr_name)
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if change_this_field is True and value != current_value:
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626
if not IObject.providedBy(element):
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628
# Do any field-specific validation.
615
field = element.bind(self.context)
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field.validate(value)
617
except ValidationError, e:
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self.request.response.setStatus(400)
629
element.validate(value)
630
except ConstraintNotSatisfied, e:
631
# Try to get a string error message out of
632
# the exception; otherwise use a generic message
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# instead of whatever object the raise site
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# thought would be a good idea.
635
if (len(e.args) > 0 and
636
isinstance(e.args[0], basestring)):
639
error = "Constraint not satisfied."
640
errors.append("%s: %s" % (repr_name, error))
642
except (ValueError, ValidationError), e:
621
645
error = "Validation error"
646
errors.append("%s: %s" % (repr_name, error))
623
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validated_changeset[name] = value
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# If there were errors, display them and send a status of 400.
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self.request.response.setStatus(400)
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self.request.response.setHeader('Content-type', 'text/plain')
654
return "\n".join(errors)
625
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# Store the entry's current URL so we can see if it changes.
626
657
original_url = canonical_url(self.context)
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658
# Make the changes.
657
688
# just needs this string served to the client.
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# No custom operation was specified. Implement a standard GET,
661
# which retrieves the items in the collection.
691
# No custom operation was specified. Implement a standard
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# GET, which serves a JSON or WADL representation of the
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entries = self.collection.find()
663
695
if entries is None:
664
696
raise NotFound(self, self.collection_name)
698
if self.getPreferredSupportedContentType() == self.WADL_TYPE:
699
result = self.toWADL().encode("utf-8")
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self.request.response.setHeader(
701
'Content-Type', self.WADL_TYPE)
665
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result = self.batch(entries, self.request)
667
705
self.request.response.setHeader('Content-type', self.JSON_TYPE)
668
706
return simplejson.dumps(result, cls=ResourceJSONEncoder)
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"""Represent this resource as a WADL application.
711
The WADL document describes the capabilities of this resource.
713
return super(CollectionResource, self).toWADL('wadl-collection.pt')
671
716
class ServiceRootResource:
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717
"""A resource that responds to GET by describing the service."""
added
removed
lib/canonical/lazr/rest/resource.py
