org.intermine.objectstore.query
Class ConstraintHelper

java.lang.Object
  org.intermine.objectstore.query.ConstraintHelper

public final class ConstraintHelper
extends java.lang.Object

Static methods to create Lists of Constraint objects in a query and Constraints in a query relating to a given QueryClass, plus helper methods for dealing with Constraints.
'left' and 'right' arguments for each constraint type are defined as follows: SimpleConstraint: left = arg1, right = arg2 (both QueryEvaluables) ClassConstraint: left = QueryClass arg1, right = a QueryClass or example object arg2 ContainsConstraint: left = the QueryReference - i.e. field of containing class right = the QueryClass this reference is constrained to SubQueryConstraint: left = the QueryClass or QueryEvaluable constrained to be in the subquery right = the query ConstraintSet: N/A

Method Summary

static void	addToList(java.util.List<Constraint> list, Constraint constraint) Adds all the constraints present in the argument into the given List.
static java.util.List<Constraint>	createList(Query query) Converts a constraint from a query into a List of Constraint objects.
static java.util.List<Constraint>	createList(Query query, FromElement fromElement) Return a List of Constraint objects that relate to the given FromElement.
static java.util.List<Constraint>	filter(java.util.List<Constraint> list, FromElement fromElement, boolean related) Return a subset of the given List that contains only Constraints that relate to the given FromElement or constraints associated with nothing if fromElement is null.
static java.lang.Object	getLeftArgument(Constraint constraint) Get the left argument of the given constraint, will return null if passed a ConstraintSet or a MultipleInBagConstraint.
protected static java.util.Set<QueryField>	getQueryFields(QueryEvaluable qe) Descends into QueryExpression and QueryFunction objects to find all instances of QueryField.
static java.lang.Object	getRightArgument(Constraint constraint) Get the right argument of the given constraint, will return null if passed a ConstraintSet or a MultipleInBagConstraint.
static boolean	isAssociatedWith(Constraint constraint, FromElement fromElement) Returns true if the constraint is associated with the given FromElement.
static boolean	isAssociatedWithNothing(Constraint c) Returns true if the given constraint is associated with no particular FromElement.
static boolean	isCrossReference(Constraint constraint) Returns true if the Constraint is a cross-reference between two QueryClasses.
static boolean	isRelatedTo(Constraint constraint, FromElement fromElement) Returns true if the constraint is associated with the given FromElement.
static boolean	isRelatedToNothing(Constraint c) Returns true if the given constraint is related to no FromElement.
static java.util.List<Constraint>	listRelatedConstraints(Query query, FromElement fromElement) Return a List of Constraint objects that relate to the given FromElement.
static void	traverseConstraints(Constraint c, ConstraintTraverseAction ca) Traverse the given Constraint tree (ie. recursively look for nested constraints if the argument is a ConstraintSet) and call ConstraintTraverseAction for each Constraint.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

createList

public static java.util.List<Constraint> createList(Query query)

Converts a constraint from a query into a List of Constraint objects.

Parameters:

query - a Query object to list Constraints for

Returns:

a List of Constraint objects

createList

public static java.util.List<Constraint> createList(Query query,
                                                    FromElement fromElement)

Return a List of Constraint objects that relate to the given FromElement.

Parameters:

query - a Query object to to list contraints for

fromElement - a FromElement that returned constraints relate to

Returns:

a List of Constraint objects

traverseConstraints

public static void traverseConstraints(Constraint c,
                                       ConstraintTraverseAction ca)

Traverse the given Constraint tree (ie. recursively look for nested constraints if the argument is a ConstraintSet) and call ConstraintTraverseAction for each Constraint.

Parameters:

c - the Constraint to traverse - could be a ConstraintSet (possibly with nested ConstraintSets)

ca - ConstraintTraverseAction.apply() is called for each Constraint found

listRelatedConstraints

public static java.util.List<Constraint> listRelatedConstraints(Query query,
                                                                FromElement fromElement)

Return a List of Constraint objects that relate to the given FromElement.

Parameters:

query - a Query object to to list contraints for

fromElement - a FromElement that returned constraints relate to

Returns:

a List of Constraint objects

filter

public static java.util.List<Constraint> filter(java.util.List<Constraint> list,
                                                FromElement fromElement,
                                                boolean related)

Return a subset of the given List that contains only Constraints that relate to the given FromElement or constraints associated with nothing if fromElement is null.

Parameters:

list - a list of Constraints to filter

fromElement - a fromElement that returned constraints relate to

related - if tru list all releted constraints, otherwise just associated

Returns:

a List of Constraint objects

addToList

public static void addToList(java.util.List<Constraint> list,
                             Constraint constraint)

Adds all the constraints present in the argument into the given List.

Parameters:

list - a List of Constraints, to which to add more entries

constraint - a Constraint to pick apart

isAssociatedWith

public static boolean isAssociatedWith(Constraint constraint,
                                       FromElement fromElement)

Returns true if the constraint is associated with the given FromElement. Associated with means relating directly to a field of the QueryClass but NOT a cross-reference contraint (which compares two arbitrary fields of different QueryClasses.

Parameters:

constraint - the constraint in question

fromElement - the FromElement to check

Returns:

true if associated

isAssociatedWithNothing

public static boolean isAssociatedWithNothing(Constraint c)

Returns true if the given constraint is associated with no particular FromElement.

Parameters:

c - the constraint to examine

Returns:

true if constraint is not associated with a FromElement

isRelatedTo

public static boolean isRelatedTo(Constraint constraint,
                                  FromElement fromElement)

Returns true if the constraint is associated with the given FromElement.

Parameters:

constraint - the constraint in question

fromElement - the FromElement to check

Returns:

true if associated

isRelatedToNothing

public static boolean isRelatedToNothing(Constraint c)

Returns true if the given constraint is related to no FromElement. This should only return true if c is a SimpleConstraint that only references constants.

Parameters:

c - the constraint to examine

Returns:

true if constraint is not associated with a FromElement

isCrossReference

public static boolean isCrossReference(Constraint constraint)

Returns true if the Constraint is a cross-reference between two QueryClasses. A constraint is deemed to be a cross-reference if it compares fields of two different QueryClasses, either directly or via QueryExpressions.

Parameters:

constraint - the contraint to test

Returns:

true if the contraint is a cross-reference

getQueryFields

protected static java.util.Set<QueryField> getQueryFields(QueryEvaluable qe)

Descends into QueryExpression and QueryFunction objects to find all instances of QueryField. Will return a single element set for QueryField and an empty set for QueryValue.

Parameters:

qe - a QueryEvalubale to find QueryFields for

Returns:

a set of QueryFields

getLeftArgument

public static java.lang.Object getLeftArgument(Constraint constraint)

Get the left argument of the given constraint, will return null if passed a ConstraintSet or a MultipleInBagConstraint.

Parameters:

constraint - a constraint

Returns:

the left argument of given constraint

getRightArgument

public static java.lang.Object getRightArgument(Constraint constraint)

Get the right argument of the given constraint, will return null if passed a ConstraintSet or a MultipleInBagConstraint.

Parameters:

constraint - a constraint

Returns:

the right argument of given constraint