org.apache.velocity.tools.generic
Class LoopTool.ManagedIterator

java.lang.Object
  org.apache.velocity.tools.generic.LoopTool.ManagedIterator

All Implemented Interfaces:

java.util.Iterator

Enclosing class:

LoopTool

public static class LoopTool.ManagedIterator
extends java.lang.Object
implements java.util.Iterator

Iterator implementation that wraps a standard Iterator and allows it to be prematurely stopped, skipped ahead, and associated with a name for advanced nested loop control. This also allows a arbitrary LoopTool.ActionConditions to be added in order to have it automatically skip over or stop before certain elements in the iterator.

Field Summary

private java.util.List<LoopTool.ActionCondition>	conditions
private int	count
private java.lang.Boolean	first
private java.util.Iterator	iterator
private java.lang.String	name
private java.lang.Object	next
private LoopTool	owner
private boolean	stopped
private java.util.Map<java.lang.String,LoopTool.SyncedIterator>	synced

Constructor Summary

LoopTool.ManagedIterator(java.lang.String name, java.util.Iterator iterator, LoopTool owner)

Method Summary

private boolean	cacheNext(boolean popWhenDone)
LoopTool.ManagedIterator	condition(LoopTool.ActionCondition condition) Adds a new LoopTool.ActionCondition for this instance to check against the elements in the iterator being managed.
LoopTool.ManagedIterator	exclude(java.lang.Object compare) Directs this instance to completely exclude any elements equal to the specified Object.
java.lang.Object	get(java.lang.String name) Returns the parallel value from the specified sync'ed iterator.
int	getCount() Returns the number of elements returned by next() so far.
boolean	getFirst() Returns the result of isFirst().
boolean	getHasNext() Returns the result of hasNext().
int	getIndex() Returns the 0-based index of the current item.
boolean	getLast() Returns the result of isLast().
java.lang.String	getName() Returns the name of this instance.
boolean	hasNext() Returns true if there are more elements in the iterator being managed by this instance which satisfy all the LoopTool.ActionConditions set for this instance.
private boolean	hasNext(boolean popWhenDone)
boolean	isFirst() Returns true if either 0 or 1 elements have been returned by next().
boolean	isLast() Returns true if the last element returned by next() is the last element available in the iterator being managed which satisfies any/all LoopTool.ActionConditions set for this instance.
boolean	isSyncedWith(java.lang.String name) Returns true if this ManagedIterator has a sync'ed iterator with the specified name.
java.lang.Object	next() Returns the next element that meets the set LoopTool.ActionConditions (if any) in the iterator being managed.
void	remove() This operation is unsupported.
private void	shiftSynced()
void	stop() Stops this iterator from doing any further iteration.
LoopTool.ManagedIterator	stop(java.lang.Object compare) Directs this instance to stop iterating immediately prior to any element equal to the specified Object.
LoopTool.ManagedIterator	sync(java.lang.Object iterable) Adds another iterator to be kept in sync with the one being managed by this instance.
LoopTool.ManagedIterator	sync(java.lang.Object iterable, java.lang.String name) Adds another iterator to be kept in sync with the one being managed by this instance.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

name

private java.lang.String name

iterator

private java.util.Iterator iterator

owner

private LoopTool owner

stopped

private boolean stopped

first

private java.lang.Boolean first

count

private int count

next

private java.lang.Object next

conditions

private java.util.List<LoopTool.ActionCondition> conditions

synced

private java.util.Map<java.lang.String,LoopTool.SyncedIterator> synced

Constructor Detail

LoopTool.ManagedIterator

public LoopTool.ManagedIterator(java.lang.String name,
                                java.util.Iterator iterator,
                                LoopTool owner)

Method Detail

getName

public java.lang.String getName()

Returns the name of this instance.

isFirst

public boolean isFirst()

Returns true if either 0 or 1 elements have been returned by next().

isLast

public boolean isLast()

Returns true if the last element returned by next() is the last element available in the iterator being managed which satisfies any/all LoopTool.ActionConditions set for this instance. Otherwise, returns false.

getFirst

public boolean getFirst()

Returns the result of isFirst(). Exists to allow $loop.this.first syntax.

getLast

public boolean getLast()

Returns the result of isLast(). Exists to allow $loop.this.last syntax.

hasNext

public boolean hasNext()

Returns true if there are more elements in the iterator being managed by this instance which satisfy all the LoopTool.ActionConditions set for this instance. Returns false if there are no more valid elements available.

Specified by:

hasNext in interface java.util.Iterator

getHasNext

public boolean getHasNext()

Returns the result of hasNext(). Exists to allow $loop.this.hasNext syntax.

hasNext

private boolean hasNext(boolean popWhenDone)

cacheNext

private boolean cacheNext(boolean popWhenDone)

shiftSynced

private void shiftSynced()

isSyncedWith

public boolean isSyncedWith(java.lang.String name)

Returns true if this ManagedIterator has a sync'ed iterator with the specified name.

get

public java.lang.Object get(java.lang.String name)

Returns the parallel value from the specified sync'ed iterator. If no sync'ed iterator exists with that name or that iterator is finished, this will return null.

getCount

public int getCount()

Returns the number of elements returned by next() so far.

getIndex

public int getIndex()

Returns the 0-based index of the current item.

next

public java.lang.Object next()

Returns the next element that meets the set LoopTool.ActionConditions (if any) in the iterator being managed. If there are none left, then this will throw a NoSuchElementException.

Specified by:

next in interface java.util.Iterator

remove

public void remove()

This operation is unsupported.

Specified by:

remove in interface java.util.Iterator

stop

public void stop()

Stops this iterator from doing any further iteration.

exclude

public LoopTool.ManagedIterator exclude(java.lang.Object compare)

Directs this instance to completely exclude any elements equal to the specified Object.

Returns:

This same LoopTool.ManagedIterator instance

stop

public LoopTool.ManagedIterator stop(java.lang.Object compare)

Directs this instance to stop iterating immediately prior to any element equal to the specified Object.

Returns:

This same LoopTool.ManagedIterator instance

condition

public LoopTool.ManagedIterator condition(LoopTool.ActionCondition condition)

Adds a new LoopTool.ActionCondition for this instance to check against the elements in the iterator being managed.

Returns:

This same LoopTool.ManagedIterator instance

sync

public LoopTool.ManagedIterator sync(java.lang.Object iterable)

Adds another iterator to be kept in sync with the one being managed by this instance. The values of the parallel iterator can be retrieved from the LoopTool under the name s"synced" (e.g. $loop.synched or $loop.get('synced')) and are automatically updated for each iteration by this instance.

NOTE: if you are sync'ing multiple iterators with the same managed iterator, you must use sync(Object,String) or else your the later iterators will simply replace the earlier ones under the default 'synced' key.

Returns:

This same LoopTool.ManagedIterator instance

See Also:

LoopTool.SyncedIterator, get(String)

sync

public LoopTool.ManagedIterator sync(java.lang.Object iterable,
                                     java.lang.String name)

Adds another iterator to be kept in sync with the one being managed by this instance. The values of the parallel iterator can be retrieved from the LoopTool under the name specified here (e.g. $loop.name or $loop.get('name')) and are automatically updated for each iteration by this instance.

Returns:

This same LoopTool.ManagedIterator instance

See Also:

LoopTool.SyncedIterator, get(String)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object