org.zkoss.zk.ui.util
Class ForEachImpl

java.lang.Object
  org.zkoss.zk.ui.util.ForEachImpl

All Implemented Interfaces:

ForEach

public class ForEachImpl
extends java.lang.Object
implements ForEach

An implementation of ForEach.

Note: the use of ForEachImpl is different from ConditionImpl. While you could use the same instance of ConditionImpl for all evaluation, each instance of ForEachImpl can be used only once (drop it after next() returns false).

Author:

tomyeh

Constructor Summary

ForEachImpl(EvaluatorRef evalr, Component comp, ExValue[] expr, ExValue begin, ExValue end)
Constructor.

ForEachImpl(EvaluatorRef evalr, Component comp, java.lang.String expr, java.lang.String begin, java.lang.String end)
Constructor.

ForEachImpl(EvaluatorRef evalr, Page page, ExValue[] expr, ExValue begin, ExValue end)
Constructor.

ForEachImpl(EvaluatorRef evalr, Page page, java.lang.String expr, java.lang.String begin, java.lang.String end)
Constructor.

Method Summary

static ForEach	getInstance(EvaluatorRef evalr, Component comp, ExValue[] expr, ExValue begin, ExValue end) Returns an instance that represents the iterator for the specified collection.
static ForEach	getInstance(EvaluatorRef evalr, Component comp, java.lang.String expr, java.lang.String begin, java.lang.String end) Returns an instance that represents the iterator for the specified collection, or null if expr is null or empty.
static ForEach	getInstance(EvaluatorRef evalr, Page page, ExValue[] expr, ExValue begin, ExValue end) Returns an instance that represents the iterator for the specified collection, or null if expr is null or empty.
static ForEach	getInstance(EvaluatorRef evalr, Page page, java.lang.String expr, java.lang.String begin, java.lang.String end) Returns an instance that represents the iterator for the specified collection, or null if expr is null or empty.
boolean	next() Advanced to the next element.

Methods inherited from class java.lang.Object

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

Constructor Detail

ForEachImpl

public ForEachImpl(EvaluatorRef evalr,
                   Component comp,
                   ExValue[] expr,
                   ExValue begin,
                   ExValue end)

Constructor. In most cases, use getInstance(EvaluatorRef, Component, ExValue[], ExValue, ExValue) instead of this constructor.

Throws:

java.lang.IllegalArgumentException - if comp or evalr is null

Since:

3.0.6

ForEachImpl

public ForEachImpl(EvaluatorRef evalr,
                   Page page,
                   ExValue[] expr,
                   ExValue begin,
                   ExValue end)

Constructor. In most cases, use getInstance(EvaluatorRef, Component, ExValue[], ExValue, ExValue) instead of this constructor.

Throws:

java.lang.IllegalArgumentException - if page or evalr is null

Since:

3.0.6

ForEachImpl

public ForEachImpl(EvaluatorRef evalr,
                   Component comp,
                   java.lang.String expr,
                   java.lang.String begin,
                   java.lang.String end)

Constructor. In most cases, use getInstance(EvaluatorRef, Component, String, String, String) instead of this constructor.

Throws:

java.lang.IllegalArgumentException - if comp or evalr is null

Since:

3.0.0

See Also:

ForEachImpl(EvaluatorRef, Component, ExValue[], ExValue, ExValue)

ForEachImpl

public ForEachImpl(EvaluatorRef evalr,
                   Page page,
                   java.lang.String expr,
                   java.lang.String begin,
                   java.lang.String end)

Constructor. In most cases, use getInstance(EvaluatorRef, Component, String, String, String) instead of this constructor.

Throws:

java.lang.IllegalArgumentException - if page or evalr is null

Since:

3.0.0

See Also:

ForEachImpl(EvaluatorRef, Page, ExValue[], ExValue, ExValue)

Method Detail

getInstance

public static ForEach getInstance(EvaluatorRef evalr,
                                  Component comp,
                                  ExValue[] expr,
                                  ExValue begin,
                                  ExValue end)

Returns an instance that represents the iterator for the specified collection.

Parameters:

expr - an array of expressions. There are two formats.

1. length == 1: it iterates thru the content of expr[0]. For example, if expr[0] is an array, all items in this array will be iterated.
2. length > 1, it will iterate thru expr[0]
3. length == 0 or expr is null, null is returned

Since:

3.0.6

getInstance

public static ForEach getInstance(EvaluatorRef evalr,
                                  Page page,
                                  ExValue[] expr,
                                  ExValue begin,
                                  ExValue end)

Returns an instance that represents the iterator for the specified collection, or null if expr is null or empty.

Parameters:

expr - an array of expressions. There are two formats.

1. length == 1: it iterates thru the content of expr[0]. For example, if expr[0] is an array, all items in this array will be iterated.
2. length > 1, it will iterate thru expr[0]
3. length == 0 or expr is null, null is returned

Since:

3.0.6

getInstance

public static ForEach getInstance(EvaluatorRef evalr,
                                  Component comp,
                                  java.lang.String expr,
                                  java.lang.String begin,
                                  java.lang.String end)

Returns an instance that represents the iterator for the specified collection, or null if expr is null or empty.

Parameters:

expr - an EL expression that shall return a collection of objects.

See Also:

getInstance(EvaluatorRef, Component, ExValue[], ExValue, ExValue)

getInstance

public static ForEach getInstance(EvaluatorRef evalr,
                                  Page page,
                                  java.lang.String expr,
                                  java.lang.String begin,
                                  java.lang.String end)

Returns an instance that represents the iterator for the specified collection, or null if expr is null or empty.

Parameters:

expr - an EL expression that shall return a collection of objects.

Since:

3.0.0

See Also:

getInstance(EvaluatorRef, Page, ExValue[], ExValue, ExValue)

next

public boolean next()

Description copied from interface: ForEach

Advanced to the next element.

Specified by:

next in interface ForEach

Returns:

false if there is no more element.