freemarker.ext.beans

Class BeanModel

Implemented Interfaces:
AdapterTemplateModel, TemplateHashModel, TemplateHashModelEx, TemplateModel, WrapperTemplateModel
Known Direct Subclasses:
ArrayModel, BooleanModel, DateModel, EnumerationModel, IteratorModel, NumberModel, ResourceBundleModel, StringModel

public class BeanModel
extends java.lang.Object
implements TemplateHashModelEx, AdapterTemplateModel, WrapperTemplateModel

A class that will wrap an arbitrary object into TemplateHashModel interface allowing calls to arbitrary property getters and invocation of accessible methods on the object from a template using the object.foo to access properties and object.bar(arg1, arg2) to invoke methods on it. You can also use the object.foo[index] syntax to access indexed properties. It uses Beans java.beans.Introspector to dynamically discover the properties and methods.
Version:
$Id: BeanModel.java,v 1.49.2.4 2006/11/12 10:20:37 szegedia Exp $
Author:
Attila Szegedi

Field Summary

protected Object
object
protected BeansWrapper
wrapper

Fields inherited from interface freemarker.template.TemplateModel

NOTHING

Constructor Summary

BeanModel(Object object, BeansWrapper wrapper)
Creates a new model that wraps the specified object.

Method Summary

TemplateModel
get(String key)
Uses Beans introspection to locate a property or method with name matching the key name.
Object
getAdaptedObject(Class hint)
Object
getWrappedObject()
protected boolean
hasPlainGetMethod()
Whether the model has a plain get(String) or get(Object) method
protected TemplateModel
invokeGenericGet(Map keyMap, Class clazz, String key)
boolean
isEmpty()
Tells whether the model is empty.
protected Set
keySet()
Helper method to support TemplateHashModelEx.
TemplateCollectionModel
keys()
int
size()
String
toString()
protected Object
unwrap(TemplateModel model)
TemplateCollectionModel
values()
protected TemplateModel
wrap(Object obj)

Field Details

object

protected final Object object

wrapper

protected final BeansWrapper wrapper

Constructor Details

BeanModel

public BeanModel(Object object,
                 BeansWrapper wrapper)
Creates a new model that wraps the specified object. Note that there are specialized subclasses of this class for wrapping arrays, collections, enumeration, iterators, and maps. Note also that the superclass can be used to wrap String objects if only scalar functionality is needed. You can also choose to delegate the choice over which model class is used for wrapping to BeansWrapper.wrap(Object).
Parameters:
object - the object to wrap into a model.
wrapper - the BeansWrapper associated with this model. Every model has to have an associated BeansWrapper instance. The model gains many attributes from its wrapper, including the caching behavior, method exposure level, method-over-item shadowing policy etc.

Method Details

get

public TemplateModel get(String key)
            throws TemplateModelException
Uses Beans introspection to locate a property or method with name matching the key name. If a method or property is found, it is wrapped into TemplateMethodModelEx (for a method or indexed property), or evaluated on-the-fly and the return value wrapped into appropriate model (for a simple property) Models for various properties and methods are cached on a per-class basis, so the costly introspection is performed only once per property or method of a class. (Side-note: this also implies that any class whose method has been called will be strongly referred to by the framework and will not become unloadable until this class has been unloaded first. Normally this is not an issue, but can be in a rare scenario where you create many classes on- the-fly. Also, as the cache grows with new classes and methods introduced to the framework, it may appear as if it were leaking memory. The framework does, however detect class reloads (if you happen to be in an environment that does this kind of things--servlet containers do it when they reload a web application) and flushes the cache. If no method or property matching the key is found, the framework will try to invoke methods with signature non-void-return-type get(java.lang.String), then non-void-return-type get(java.lang.Object), or alternatively (if the wrapped object is a resource bundle) Object getObject(java.lang.String).
Specified by:
get in interface TemplateHashModel
Throws:
TemplateModelException - if there was no property nor method nor a generic get method to invoke.

getAdaptedObject

public Object getAdaptedObject(Class hint)
Specified by:
getAdaptedObject in interface AdapterTemplateModel

getWrappedObject

public Object getWrappedObject()
Specified by:
getWrappedObject in interface WrapperTemplateModel

hasPlainGetMethod

protected boolean hasPlainGetMethod()
Whether the model has a plain get(String) or get(Object) method

invokeGenericGet

protected TemplateModel invokeGenericGet(Map keyMap,
                                         Class clazz,
                                         String key)
            throws IllegalAccessException,
                   InvocationTargetException,
                   TemplateModelException

isEmpty

public boolean isEmpty()
Tells whether the model is empty. It is empty if either the wrapped object is null, or it is a Boolean with false value.
Specified by:
isEmpty in interface TemplateHashModel

keySet

protected Set keySet()
Helper method to support TemplateHashModelEx. Returns the Set of Strings which are available via the TemplateHashModel interface. Subclasses that override invokeGenericGet to provide additional hash keys should also override this method.

keys

public TemplateCollectionModel keys()
Specified by:
keys in interface TemplateHashModelEx

size

public int size()
Specified by:
size in interface TemplateHashModelEx

toString

public String toString()

unwrap

protected Object unwrap(TemplateModel model)
            throws TemplateModelException

values

public TemplateCollectionModel values()
            throws TemplateModelException
Specified by:
values in interface TemplateHashModelEx

wrap

protected TemplateModel wrap(Object obj)
            throws TemplateModelException