freemarker.ext.misc
Class HashKeys

java.lang.Object
  freemarker.ext.misc.HashKeys

All Implemented Interfaces:

TemplateMethodModel2, TemplateModel, java.io.Serializable

public final class HashKeys
extends java.lang.Object
implements TemplateMethodModel2, java.io.Serializable

Determines the keyset of the underlying Map object given a TemplateObjectModel. Does this by calling the getAsObject method. If the object is of the expected type, the keyset is returned as a FastList. Otherwise, a TemplateModelException is thrown.

Usage:
From java:

 TemplateModelRoot root = new SimpleHash();

 root.put( "keys", freemarker.ext.misc.HashKeys.getInstance() );

 ...
 

From your FM-Classic template:

 <assign hash1 = { "test1", "value1",
                      "test2", "value2",
                      "test3", "value3" }>
 <assign keyList = keys( hash1 )>
 <p>The keys of hash1 are:</p>
 <p><foreach key in keyList>
 ${key}<br>
 </foreach></p>

 ...
 

Note:
HashKeys is a singleton instance. Use the getInstance() method to retrieve instances of this model.

Since:

1.8

Version:

$Id: HashKeys.java 1101 2013-04-01 04:17:32Z run2000 $

Author:

Nicholas Cull

See Also:

Serialized Form

Method Summary

TemplateModel	exec(java.util.List<TemplateModel> arguments) Executes a method call.
static HashKeys	getInstance() Retrieve a singleton instance of this class.
boolean	isEmpty() Is the object empty?

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static HashKeys getInstance()

Retrieve a singleton instance of this class. Since there is no state information held between calls, there is only a need for one instance.

Returns:

an instance of this HashKeys class

isEmpty

public boolean isEmpty()
                throws TemplateModelException

Is the object empty?

Specified by:

isEmpty in interface TemplateModel

Returns:

false, since the method is never empty

Throws:

TemplateModelException

exec

public TemplateModel exec(java.util.List<TemplateModel> arguments)
                   throws TemplateModelException

Executes a method call. Arguments are passed as a List of TemplateModel objects.

Specified by:

exec in interface TemplateMethodModel2

Parameters:

arguments - a List of TemplateModel objects containing the values of the arguments passed to the method.

Returns:

the TemplateModel produced by the method, or null.

Throws:

TemplateModelException