org.modeshape.graph.query.model
Class Visitors

java.lang.Object
  org.modeshape.graph.query.model.Visitors

public class Visitors
extends Object

A set of common visitors that can be reused or extended, and methods that provide easy construction and calling of visitors.

Nested Class Summary

static class	Visitors.AbstractVisitor A common base class for all visitors, which provides no-op implementations for all visit(...) methods.
static class	Visitors.NavigationVisitor An abstract visitor implementation that performs navigation of the query object.
static class	Visitors.ReadableVisitor
static class	Visitors.WalkAllVisitor A visitor implementation that walks the entire query object tree and delegates to another supplied visitor to do the actual work.

Constructor Summary

Visitors()

Method Summary

static Map<SelectorName,SelectorName>	getSelectorAliasesByName(Visitable visitable) Get a map of the selector aliases keyed by their names.
static Map<SelectorName,SelectorName>	getSelectorNamesByAlias(Visitable visitable) Get a map of the selector names keyed by their aliases.
static Set<SelectorName>	getSelectorsReferencedBy(Visitable visitable) Get the names of the selectors referenced by the visitable object.
static String	readable(Visitable visitable) Using a visitor, obtain the readable string representation of the supplied object
static Collection<Subquery>	subqueries(Visitable visitable, boolean includeNestedSubqueries) Using a visitor, obtain the Subquery objects that are contained within the supplied object.
static <GeneralVisitor extends Visitor> GeneralVisitor	visit(Visitable visitable, GeneralVisitor visitor) Visit the supplied object using the supplied Visitors.AbstractVisitor, which must be responsible for navigation as well as any business logic.
static <StrategyVisitor extends Visitor> StrategyVisitor	visitAll(Visitable visitable, StrategyVisitor strategyVisitor) Visit all objects in the supplied object using a Visitors.NavigationVisitor (specifically a Visitors.WalkAllVisitor), and with each of these visited objects calling the appropriate visit(...) method on the supplied Visitors.AbstractVisitor.

Methods inherited from class java.lang.Object

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

Constructor Detail

Visitors

public Visitors()

Method Detail

visitAll

public static <StrategyVisitor extends Visitor> StrategyVisitor visitAll(Visitable visitable,
                                                                         StrategyVisitor strategyVisitor)

Visit all objects in the supplied object using a Visitors.NavigationVisitor (specifically a Visitors.WalkAllVisitor), and with each of these visited objects calling the appropriate visit(...) method on the supplied Visitors.AbstractVisitor.

Type Parameters:

StrategyVisitor - the type of strategy visitor

Parameters:

visitable - the top-level object to be visited

strategyVisitor - the visitor that is to be called for each visited objects, but that does not call Visitable.accept(Visitor)

Returns:

the strategy visitor, allowing the caller to easily invoke operations on the visitor after visitation has completed

visit

public static <GeneralVisitor extends Visitor> GeneralVisitor visit(Visitable visitable,
                                                                    GeneralVisitor visitor)

Visit the supplied object using the supplied Visitors.AbstractVisitor, which must be responsible for navigation as well as any business logic.

Type Parameters:

GeneralVisitor - the type of visitor

Parameters:

visitable - the top-level object to be visited

visitor - the visitor that is to be used

Returns:

the visitor, allowing the caller to easily invoke operations on the visitor after visitation has completed

readable

public static String readable(Visitable visitable)

Using a visitor, obtain the readable string representation of the supplied object

Parameters:

visitable - the visitable

Returns:

the string representation

subqueries

public static Collection<Subquery> subqueries(Visitable visitable,
                                              boolean includeNestedSubqueries)

Using a visitor, obtain the Subquery objects that are contained within the supplied object. This method does find Subquery objets nested in other Subquery objects.

Parameters:

visitable - the visitable

includeNestedSubqueries - true if any Subquery objects within other Subquery objects should be included, or false if only the top-level Subquery objects should be included

Returns:

the collection of subqueries; never null but possibly empty if no subqueries were found

getSelectorNamesByAlias

public static Map<SelectorName,SelectorName> getSelectorNamesByAlias(Visitable visitable)

Get a map of the selector names keyed by their aliases.

Parameters:

visitable - the object to be visited

Returns:

the map from the aliases to the aliased selector name; never null but possibly empty

getSelectorAliasesByName

public static Map<SelectorName,SelectorName> getSelectorAliasesByName(Visitable visitable)

Get a map of the selector aliases keyed by their names.

Parameters:

visitable - the object to be visited

Returns:

the map from the selector names to their alias (or name if there is no alias); never null but possibly empty

getSelectorsReferencedBy

public static Set<SelectorName> getSelectorsReferencedBy(Visitable visitable)

Get the names of the selectors referenced by the visitable object.

Parameters:

visitable - the object to be visited

Returns:

the set of selector names referenced in some way by the visitable; never null