freemarker.template

Class DefaultListAdapter

java.lang.Object

freemarker.template.WrappingTemplateModel

freemarker.template.DefaultListAdapter

All Implemented Interfaces:

WrapperTemplateModel, AdapterTemplateModel, TemplateModel, TemplateModelWithAPISupport, TemplateSequenceModel, java.io.Serializable

public class DefaultListAdapter
extends WrappingTemplateModel
implements TemplateSequenceModel, AdapterTemplateModel, WrapperTemplateModel, TemplateModelWithAPISupport, java.io.Serializable

Adapts a List to the corresponding TemplateModel interface(s), most importantly to TemplateSequenceModel. If you aren't wrapping an already existing List, but build a sequence specifically to be used from a template, also consider using SimpleSequence (see comparison there).

Thread safety: A DefaultListAdapter is as thread-safe as the List that it wraps is. Normally you only have to consider read-only access, as the FreeMarker template language doesn't allow writing these sequences (though of course, Java methods called from the template can violate this rule).

This adapter is used by DefaultObjectWrapper if its useAdaptersForCollections property is true, which is the default when its incompatibleImprovements property is 2.3.22 or higher.

Since:

2.3.22

See Also:

SimpleSequence, DefaultArrayAdapter, TemplateSequenceModel, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.List	list

Fields inherited from interface freemarker.template.TemplateModel

NOTHING

Method Summary

Modifier and Type	Method and Description
static DefaultListAdapter	adapt(java.util.List list, RichObjectWrapper wrapper) Factory method for creating new adapter instances.
TemplateModel	get(int index) Retrieves the i-th template model in this sequence.
java.lang.Object	getAdaptedObject(java.lang.Class hint) Retrieves the underlying object, or some other object semantically equivalent to its value narrowed by the class hint.
TemplateModel	getAPI() Returns the model that exposes the (Java) API of the value.
java.lang.Object	getWrappedObject() Retrieves the original object wrapped by this model.
int	size()

Methods inherited from class freemarker.template.WrappingTemplateModel

getDefaultObjectWrapper, getObjectWrapper, setDefaultObjectWrapper, setObjectWrapper, wrap

Methods inherited from class java.lang.Object

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

Field Detail

list

protected final java.util.List list

Method Detail

adapt

public static DefaultListAdapter adapt(java.util.List list,
                                       RichObjectWrapper wrapper)

Factory method for creating new adapter instances.

Parameters:

list - The list to adapt; can't be null.

wrapper - The ObjectWrapper used to wrap the items in the array.

get

public TemplateModel get(int index)
                  throws TemplateModelException

Description copied from interface: TemplateSequenceModel

Retrieves the i-th template model in this sequence.

Specified by:

get in interface TemplateSequenceModel

Returns:

the item at the specified index, or null if the index is out of bounds. Note that a null value is interpreted by FreeMarker as "variable does not exist", and accessing a missing variables is usually considered as an error in the FreeMarker Template Language, so the usage of a bad index will not remain hidden, unless the default value for that case was also specified in the template.

Throws:

TemplateModelException

size

public int size()
         throws TemplateModelException

Specified by:

size in interface TemplateSequenceModel

Returns:

the number of items in the list.

Throws:

TemplateModelException

getAdaptedObject

public java.lang.Object getAdaptedObject(java.lang.Class hint)

Description copied from interface: AdapterTemplateModel

Retrieves the underlying object, or some other object semantically equivalent to its value narrowed by the class hint.

Specified by:

getAdaptedObject in interface AdapterTemplateModel

Parameters:

hint - the desired class of the returned value. An implementation should make reasonable effort to retrieve an object of the requested class, but if that is impossible, it must at least return the underlying object as-is. As a minimal requirement, an implementation must always return the exact underlying object when hint.isInstance(underlyingObject) holds. When called with java.lang.Object.class, it should return a generic Java object (i.e. if the model is wrapping a scripting language object that is further wrapping a Java object, the deepest underlying Java object should be returned).

Returns:

the underlying object, or its value accommodated for the hint class.

getWrappedObject

public java.lang.Object getWrappedObject()

Description copied from interface: WrapperTemplateModel

Retrieves the original object wrapped by this model.

Specified by:

getWrappedObject in interface WrapperTemplateModel

getAPI

public TemplateModel getAPI()
                     throws TemplateModelException

Description copied from interface: TemplateModelWithAPISupport

Returns the model that exposes the (Java) API of the value. This is usually implemented by delegating to ObjectWrapperWithAPISupport.wrapAsAPI(Object).

Specified by:

getAPI in interface TemplateModelWithAPISupport

Throws:

TemplateModelException