Copyright © 2010 Open Geospatial Consortium
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A service shall support the ability to lock more than one set of features where each feature may only be locked by one lock. Each of the locks is independent when viewed from the service defined by the WFS specification.
LockFeature Request
Lock
Active Lock
Processing Transaction
Some lock requests failed Lock action = All
LockFeature Response
Some lock requests failed Lock action = Some
LockFeature Response All lock requests succeeded
LockFeature Response
Transaction Request Error occurs, e.g., invalid lock
Transaction Response Requesting
Lock
Lock expires
Processing complete, Some features not modified,
Release action = some Set lock ID = valid,
Transaction Response Transaction Request
Set lock ID = invalid, LockFeature Response
Processing complete Release action = all
Transaction Response Processing complete,
All features modified, Release action = some
Transaction Response All lock requests failed
LockFeature Response
Figure 20 — State diagram for a WFS lock 12.3 Response
12.3.1 Response semantics
Figure 21 describes the schema of a LockFeature response.
LockFeatureResponse + lock Id : CharacterString
+ feat uresLocked [0..] : ResourceId + feat uresNotLoc ked [ 0..] : ResourceId
Figure 21 — LockFeature response
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12.3.2 XML-encoding
The following XML Schema fragment defines the XML encoding of a LockFeature response:
xsd:element name=LockFeatureResponse type=wfs:LockFeatureResponseType xsd:complexType name=LockFeatureResponseType
xsd:sequence xsd:element name=FeaturesLocked
type=wfs:FeaturesLockedType minOccurs=0 xsd:element name=FeaturesNotLocked
type=wfs:FeaturesNotLockedType minOccurs=0 xsd:sequence
xsd:attribute name=lockId type=xsd:string xsd:complexType
xsd:complexType name=FeaturesLockedType xsd:sequence maxOccurs=unbounded
xsd:element ref=fes:ResourceId xsd:sequence
xsd:complexType xsd:complexType name=FeaturesNotLockedType
xsd:sequence maxOccurs=unbounded xsd:element ref=fes:ResourceId
xsd:sequence xsd:complexType
In response to a LockFeature request, a web feature service shall generate a wfs:LockFeatureResponse element. This document shall contain a lock identifier that a client application may use in subsequent WFS
operations to operate upon the set of locked feature instances. The response may also contain the optional elements wfs:FeaturesLocked and wfs:FeaturesNotLocked depending on the value of the lockAction attribute
see 13.2.4.2.
If the lock action is specified as ALL and all identified feature instances are successfully locked, a WFS shall respond with a wfs:WFS_LockFeatureResponse element that contains the wfs:FeaturesLocked element and
no wfs:FeatureNotLocked element since either all identified feature instances may be locked or none at all. If some or all feature instances cannot be locked, a WFS shall respond with an exception indicating that the lock
request failed because some or all feature instances are locked by other clients.
If the lock action is specified as SOME, then the wfs:WFS_LockFeatureResponse element shall contain the wfs:FeaturesLocked and wfs:FeatureNotLocked elements. The wfs:FeaturesLocked element shall list the
feature identifiers of all the feature instances that were locked by the LockFeature request. The wfs:FeaturesNotLocked element shall contain a list of feature identifiers for the feature instances that could
not be locked by the web feature service possibly because they were already locked by someone else. If the lock request results in no features being locked, then a WFS shall respond with wfs:LockFeatureResponse
document that contains a value for the lockId attribute but that contains neither a wfs:FeaturesLocked element nor a wfs:FeatureNotLocked element. In other words, an empty response. After the request is completed, the
lockId shall be immediately released since no resources were locked. If that same lockId is used in a subsequent transaction an InvalidLockId exception shall be raised, as described in 7.5, since that lockId value
no longer exists.
No assumption is made about the format of the lock identifier. The only requirement is that it can be expressed in the character set of the transaction request.
12.4 Exceptions
If a WFS does not implement the LockFeature operation then it shall generate an OperationNotSupported exception, indicating that the operation is not supported, if such a request is encountered.
In the event that a web feature service does support the LockFeature operation and encounters an error parsing the request, it shall raise an OperationParsingFailed exception as described in 7.5.
In the event that a web feature service does support the LockFeature operation and encounters an error processing the request, it shall raise an OperationProcessingFailed exception as described in 7.5.
