org.eclipse.emf.validation
Interface IValidationContext
-
public interface IValidationContext
Interface providing contextual information to
AbstractModelConstraints about the validation currently in progress.
Also provides some useful services to manipulate a constraint's environment.
The context knows at any point in time what constraint is currently being
evaluated on which model element. Thus, the context will seem to know
what constraint implementation is calling it, but this is just a consequence
of the fact that constraints are invoked strictly one at a time by the
context, itself.
A single constraint implementation may check multiple conditions. In such
cases, it can return a
multi-status of
multiple results created by the overloaded variants of the
ConstraintStatus.createStatus(IValidationContext, Collection, String, Object[])
method.
Note that the results of any method calls on the context object are
only valid during the invocation of the constraint's
validate() method. The results
should not be retained by a constraint implementation.
This interface should not be implemented outside of the validation framework.
getCurrentConstraintId
String getCurrentConstraintId()
- Obtains the ID of the constraint currently being evaluated. This is
useful for a class that implements multiple different constraints to
determine for which constraint it is being invoked.
-
-
Returns:
- the ID of the constraint currently being evaluated
-
See Also:
-
AbstractModelConstraint
getTarget
EObject getTarget()
- Obtains the EMF object currently being validated.
-
-
Returns:
- the current validation target
getEventType
EMFEventType getEventType()
- In the case of a live constraint evaluation, obtains the type of event
which is currently being validated.
-
-
Returns:
- the live constraint's triggering event type, or
EMFEventType.NULL if the constraint is being evaluated in
batch mode
getAllEvents
List<
Notification> getAllEvents()
- Gets all of the
Notifications that are currently being validated.
This is useful for live constraints that need more contextual information
about the changes being validated than is available in a single
notification.
-
-
Returns:
- the raw
Notifications being validated, or an empty
list if this is a batch validation. This list is not modifiable
getFeature
EStructuralFeature getFeature()
- In the case of a live constraint evaluation, obtains the particular
feature on which the constraint is triggered. Note that this only
applies to constraints that are triggered by specific features; the
result will be
null if the constraint does not specify any
feature triggers in the XML meta-data.
-
-
Returns:
- the feature constraint's triggering feature, or
null if the constraint is not triggered by a particular
feature -
See Also:
-
getFeatureNewValue()
getFeatureNewValue
Object getFeatureNewValue()
-
In the case of live constraint evaluation that is triggered by a
particular feature, obtains the new value of the feature that is being
validated. The exact contents of the result are as follows:
- Add or Add Many: in the "Add" case, a single object added to the
feature. In "Add Many" case, a collection of objects added
- Remove or Remove Many: in the "Remove" case, a single object
removed from the feature. In "Remove Many" case, a collection of
objects removed
- Set, Unset, or Move: the final value of the feature at the end
of the transaction (i.e., its current value)
- Create: a single object or a collection of objects created in the
feature
- Resolved: a single object or a collection of objects resolved
in the feature
- Resolving Adapter: a single adapter or a collection of adapters
removed from the adapter list of the
target
- Others: the final value of the feature at the end
of the transaction (i.e., its current value)
.
-
-
Returns:
- the feature constraint's triggering new value (as a single
object or a
Collection
), or null if the
constraint is not triggered by a particular feature -
See Also:
-
getFeature()
skipCurrentConstraintFor
void skipCurrentConstraintFor(
EObject eObject)
-
Causes the current constraint to be skipped in any subsequent validation
of the specified eObject in the current validation
operation. Constraints can use this facility to short-circuit
processing, especially in a recursive batch validation, of objects that
they have already checked in processing the current
target.
For example, checking for dependency cycles in a UML model requires
traversing the dependency relationships from an element as far as they
reach throughout the model. Every element thus traversed can
subsequently be ignored by the constraint, as ground that needs not be
trodden again, whether a cycle was found or not.
Note that there is no need to invoke this method for the
current target object; the validation system
guarantees that it will not be revisited.
-
-
Parameters:
-
eObject - the model object to be skipped by the current constraint
skipCurrentConstraintForAll
void skipCurrentConstraintForAll(
Collection<?> eObjects)
- Causes the current constraint to be skipped in any subsequent validation
of any of the specified
eObjects in the current validation
operation.
-
-
Parameters:
-
eObjects - the model objects to be skipped by the current constraint -
See Also:
-
skipCurrentConstraintFor(EObject)
disableCurrentConstraint
void disableCurrentConstraint(
Throwable exception)
-
Causes the current constraint to be disabled for the remainder of the
Eclipse session, because it is no longer viable due to some run-time
exception.
Note how this differs from the
skipCurrentConstraintFor(EObject) method: the current constraint
is skipped for all model elements and even in subsequent validation
operations.
-
-
Parameters:
-
exception - the exception that has caused the current constraint to
be non-viable. Must not be null
getCurrentConstraintData
Object getCurrentConstraintData()
-
Gets the current constraint's private working data. This object can be
anything that the caller defines. The value is null
until it is set by this same constraint using the
putCurrentConstraintData(java.lang.Object) method. The working data persists
only for the duration of the validation operation.
The constraint may use this to cache any data that may be of use to it
in optimizing the processing of multiple objects, reporting information
to the user, etc.
-
-
Returns:
- the current constraint's working data
-
See Also:
-
putCurrentConstraintData(Object)
putCurrentConstraintData
Object putCurrentConstraintData(
Object newData)
- Puts into this context some working data that is to be cached for the
current constraint. The data may be retrieved later by a call to the
getCurrentConstraintData() method during the same validation
operation.
-
-
Parameters:
-
newData - the new working data
-
Returns:
- the previous constraint data object that the
newData is displacing
getResultLocus
Set<
EObject> getResultLocus()
- Obtains the result locus of this evaluation of the current constraint.
The returned set is not modifiable.
-
-
Returns:
- an unmodifiable view of the result locus
-
See Also:
-
addResult(EObject)
addResult
void addResult(
EObject eObject)
- Adds a result to the result locus of the current constraint. The result
locus is the set of model elements that contribute to the violation of
a constraint. The
current target is implicitly
added to the result locus if the constraint evaluation fails.
-
-
Parameters:
-
eObject - the model element to add to the result locus -
See Also:
-
getResultLocus()
addResults
void addResults(
Collection<? extends
EObject> eObjects)
- Adds all of the specified model elements to the result locus of the
current constraint.
-
-
Parameters:
-
eObjects - the model elements to add to the result locus. Must
contain elements of type
EObject
-
See Also:
-
addResult(EObject)
createSuccessStatus
IStatus createSuccessStatus()
- Creates a status object indicating successful evaluation of the
current constraint on the current target element.
-
-
Returns:
- the "success" status
createFailureStatus
IStatus createFailureStatus(
Object... messageArgument)
- Creates a status object indicating unsuccessful evaluation of the
current constraint on the current target element. The status will have
the severity, error code, and message defined in the constraint meta-data
in the XML.
-
-
Parameters:
-
messageArgument - the positional {0}, {1}, etc. arguments to
replace in the message pattern (may by null if none
are needed)
-
Returns:
- the status indicating a constraint violation
