graphql.util

Class DefaultTraverserContext<T>

java.lang.Object

graphql.util.DefaultTraverserContext<T>

All Implemented Interfaces:

TraverserContext<T>

public class DefaultTraverserContext<T>
extends java.lang.Object
implements TraverserContext<T>

Nested Class Summary

Nested classes/interfaces inherited from interface graphql.util.TraverserContext

TraverserContext.Phase

Constructor Summary

Constructors

Constructor and Description
DefaultTraverserContext(T curNode, TraverserContext<T> parent, java.util.Set<T> visited, java.util.Map<java.lang.Class<?>,java.lang.Object> vars, java.lang.Object sharedContextData, NodeLocation location, boolean isRootContext, boolean parallel)

Method Summary

Modifier and Type	Method and Description
void	changeNode(T newNode) Change the current node to the provided node.
void	deleteNode() Deletes the current node.
static <T> DefaultTraverserContext<T>	dummy()
java.util.List<Breadcrumb<T>>	getBreadcrumbs() The exact location of this node inside the tree as a list of Breadcrumb
java.util.Map<java.lang.String,java.util.List<TraverserContext<T>>>	getChildrenContexts() In case of leave returns the children contexts, which have already been visited.
<U> U	getCurrentAccumulate() The current accumulate value used as "input" for the current step.
NodeLocation	getLocation() The location of the current node regarding to the parent node.
<U> U	getNewAccumulate() The new accumulate value, previously set by TraverserContext.setAccumulate(Object) or TraverserContext.getCurrentAccumulate() if TraverserContext.setAccumulate(Object) not invoked.
TraverserContext<T>	getParentContext() Returns parent context.
T	getParentNode() The parent node.
java.util.List<T>	getParentNodes() The list of parent nodes starting from the current parent.
TraverserContext.Phase	getPhase()
java.lang.Object	getSharedContextData() Used to share something across all TraverserContext.
<S> S	getVar(java.lang.Class<? super S> key) Obtains a context local variable
<S> S	getVarFromParents(java.lang.Class<? super S> key) Searches for a context variable starting from the parent up the hierarchy of contexts until the first variable is found.
boolean	isChanged()
boolean	isDeleted()
boolean	isParallel()
boolean	isRootContext() Returns true for the root context, which doesn't have a node or a position.
boolean	isVisited() Informs that the current node has been already "visited"
T	originalThisNode() Returns the original, unchanged, not deleted Node.
void	setAccumulate(java.lang.Object accumulate) Sets the new accumulate value.
<S> TraverserContext<T>	setVar(java.lang.Class<? super S> key, S value) Stores a variable in the context
static <T> DefaultTraverserContext<T>	simple(T node)
T	thisNode() Returns current node being visited.
java.util.Set<T>	visitedNodes() Obtains all visited nodes and values received by the TraverserVisitor.enter(graphql.util.TraverserContext) method

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultTraverserContext

public DefaultTraverserContext(T curNode,
                               TraverserContext<T> parent,
                               java.util.Set<T> visited,
                               java.util.Map<java.lang.Class<?>,java.lang.Object> vars,
                               java.lang.Object sharedContextData,
                               NodeLocation location,
                               boolean isRootContext,
                               boolean parallel)

Method Detail

dummy

public static <T> DefaultTraverserContext<T> dummy()

simple

public static <T> DefaultTraverserContext<T> simple(T node)

thisNode

public T thisNode()

Description copied from interface: TraverserContext

Returns current node being visited. Special cases: It is null for the root context and it is the changed node after TraverserContext.changeNode(Object) is called. Throws Exception if the node is deleted.

Specified by:

thisNode in interface TraverserContext<T>

Returns:

current node traverser is visiting.

originalThisNode

public T originalThisNode()

Description copied from interface: TraverserContext

Returns the original, unchanged, not deleted Node.

Specified by:

originalThisNode in interface TraverserContext<T>

Returns:

the original node

changeNode

public void changeNode(T newNode)

Description copied from interface: TraverserContext

Change the current node to the provided node. Only applicable in enter. Useful when the tree should be changed while traversing. Also: changing a node makes only a difference when it has different children than the current one.

Specified by:

changeNode in interface TraverserContext<T>

Parameters:

newNode - the new Node

deleteNode

public void deleteNode()

Description copied from interface: TraverserContext

Deletes the current node.

Specified by:

deleteNode in interface TraverserContext<T>

isDeleted

public boolean isDeleted()

Specified by:

isDeleted in interface TraverserContext<T>

Returns:

true if the current node is deleted (by calling TraverserContext.deleteNode()

isChanged

public boolean isChanged()

Specified by:

isChanged in interface TraverserContext<T>

Returns:

true if the current node is changed (by calling TraverserContext.changeNode(Object)

getParentContext

public TraverserContext<T> getParentContext()

Description copied from interface: TraverserContext

Returns parent context. Effectively organizes Context objects in a linked list so by following TraverserContext.getParentContext() links one could obtain the current path as well as the variables TraverserContext.getVar(java.lang.Class) stored in every parent context.

Specified by:

getParentContext in interface TraverserContext<T>

Returns:

context associated with the node parent

getParentNodes

public java.util.List<T> getParentNodes()

Description copied from interface: TraverserContext

The list of parent nodes starting from the current parent.

Specified by:

getParentNodes in interface TraverserContext<T>

Returns:

list of parent nodes

getBreadcrumbs

public java.util.List<Breadcrumb<T>> getBreadcrumbs()

Description copied from interface: TraverserContext

The exact location of this node inside the tree as a list of Breadcrumb

Specified by:

getBreadcrumbs in interface TraverserContext<T>

Returns:

list of breadcrumbs. the first element is the location inside the parent.

getParentNode

public T getParentNode()

Description copied from interface: TraverserContext

The parent node.

Specified by:

getParentNode in interface TraverserContext<T>

Returns:

The parent node.

visitedNodes

public java.util.Set<T> visitedNodes()

Description copied from interface: TraverserContext

Obtains all visited nodes and values received by the TraverserVisitor.enter(graphql.util.TraverserContext) method

Specified by:

visitedNodes in interface TraverserContext<T>

Returns:

a map containing all nodes visited and values passed when visiting nodes for the first time

isVisited

public boolean isVisited()

Description copied from interface: TraverserContext

Informs that the current node has been already "visited"

Specified by:

isVisited in interface TraverserContext<T>

Returns:

true if a node had been already visited

getVar

public <S> S getVar(java.lang.Class<? super S> key)

Description copied from interface: TraverserContext

Obtains a context local variable

Specified by:

getVar in interface TraverserContext<T>

Type Parameters:

S - type of the variable

Parameters:

key - key to lookup the variable value

Returns:

a variable value or null

setVar

public <S> TraverserContext<T> setVar(java.lang.Class<? super S> key,
                                      S value)

Description copied from interface: TraverserContext

Stores a variable in the context

Specified by:

setVar in interface TraverserContext<T>

Type Parameters:

S - type of a variable

Parameters:

key - key to create bindings for the variable

value - value of variable

Returns:

this context to allow operations chaining

setAccumulate

public void setAccumulate(java.lang.Object accumulate)

Description copied from interface: TraverserContext

Sets the new accumulate value. Can be retrieved by TraverserContext.getNewAccumulate()

Specified by:

setAccumulate in interface TraverserContext<T>

Parameters:

accumulate - to set

getNewAccumulate

public <U> U getNewAccumulate()

Description copied from interface: TraverserContext

The new accumulate value, previously set by TraverserContext.setAccumulate(Object) or TraverserContext.getCurrentAccumulate() if TraverserContext.setAccumulate(Object) not invoked.

Specified by:

getNewAccumulate in interface TraverserContext<T>

Type Parameters:

U - and me

Returns:

the new accumulate value

getCurrentAccumulate

public <U> U getCurrentAccumulate()

Description copied from interface: TraverserContext

The current accumulate value used as "input" for the current step.

Specified by:

getCurrentAccumulate in interface TraverserContext<T>

Type Parameters:

U - and me

Returns:

the current accumulate value

getSharedContextData

public java.lang.Object getSharedContextData()

Description copied from interface: TraverserContext

Used to share something across all TraverserContext.

Specified by:

getSharedContextData in interface TraverserContext<T>

Returns:

contextData

getLocation

public NodeLocation getLocation()

Description copied from interface: TraverserContext

The location of the current node regarding to the parent node.

Specified by:

getLocation in interface TraverserContext<T>

Returns:

the position or null if this node is a root node

isRootContext

public boolean isRootContext()

Description copied from interface: TraverserContext

Returns true for the root context, which doesn't have a node or a position.

Specified by:

isRootContext in interface TraverserContext<T>

Returns:

true for the root context, otherwise false

getVarFromParents

public <S> S getVarFromParents(java.lang.Class<? super S> key)

Description copied from interface: TraverserContext

Searches for a context variable starting from the parent up the hierarchy of contexts until the first variable is found.

Specified by:

getVarFromParents in interface TraverserContext<T>

Type Parameters:

S - type of the variable

Parameters:

key - key to lookup the variable value

Returns:

a variable value or null

getChildrenContexts

public java.util.Map<java.lang.String,java.util.List<TraverserContext<T>>> getChildrenContexts()

Description copied from interface: TraverserContext

In case of leave returns the children contexts, which have already been visited.

Specified by:

getChildrenContexts in interface TraverserContext<T>

Returns:

the children contexts. If the childs are a simple list the key is null.

getPhase

public TraverserContext.Phase getPhase()

Specified by:

getPhase in interface TraverserContext<T>

Returns:

the phase in which the node visits currently happens (Enter,Leave or BackRef)

isParallel

public boolean isParallel()

Specified by:

isParallel in interface TraverserContext<T>

Returns:

true if the traversing happens in parallel (multi threaded) or not.