Package freemarker.ext.beans

Interface MethodAppearanceFineTuner

public interface MethodAppearanceFineTuner

Used for customizing how the Java methods are visible from templates, via BeansWrapper.setMethodAppearanceFineTuner(MethodAppearanceFineTuner). The object that implements this should also implement SingletonCustomizer whenever possible, to allow reusing the class introspection cache in more situations.

Since:

2.3.21

Method Summary

Modifier and Type	Method	Description
void	process(BeansWrapper.MethodAppearanceDecisionInput in, BeansWrapper.MethodAppearanceDecision out)	Implement this to tweak certain aspects of how methods appear in the data-model.

Method Details

process

void process(BeansWrapper.MethodAppearanceDecisionInput in,
 BeansWrapper.MethodAppearanceDecision out)

Implement this to tweak certain aspects of how methods appear in the data-model. BeansWrapper will pass in all Java methods here that it intends to expose in the data-model as methods (so you can do obj.foo() in the template). This also applies to JavaBeans property read methods, like public int getX(), even if the bean property value itself is already exposed (with name x, in this example).

With this method you can do the following tweaks:

• Hide a method that would be otherwise shown by calling BeansWrapper.MethodAppearanceDecision.setExposeMethodAs(String) with null parameter. Note that you can't un-hide methods that are not public or are considered to by unsafe (like Object.wait()) because process(freemarker.ext.beans.BeansWrapper.MethodAppearanceDecisionInput, freemarker.ext.beans.BeansWrapper.MethodAppearanceDecision) is not called for those.
• Show the method with a different name in the data-model than its real name by calling BeansWrapper.MethodAppearanceDecision.setExposeMethodAs(String) with non-null parameter. (If set to null, then the method won't be exposed.) The default is the real name of the method. Note that if methodInsteadOfPropertyValueBeforeCall is true, the method is not exposed if the method name set here is the same as the name of the property set for this method with BeansWrapper.MethodAppearanceDecision.setExposeAsProperty(PropertyDescriptor).
• Create a fake JavaBean property for this method by calling BeansWrapper.MethodAppearanceDecision.setExposeAsProperty(PropertyDescriptor). For example, if you have int size() in a class, but you want it to be accessed from the templates as obj.size (like a JavaBean property), rather than as obj.size(), you can do that with this (but remember calling setMethodShadowsProperty(false) as well, if the method name is exactly the same as the property name). The default is null, which means that no fake property is created for the method. You need not, and shouldn't set this to non-null for the property read (get/is) methods of real JavaBeans properties, as bean properties are not treated as methods (hence the MethodAppearanceFineTuner is irrelevant), and are exposed or not regardless of this mechanism (based on BeansWrapperConfiguration.setExposureLevel(int)). The property name in the PropertyDescriptor can be anything, but the method (or methods) in it must belong to the class that is given as the clazz parameter, or it must be inherited from that class, otherwise the behavior is undefined, and errors can occur later. IndexedPropertyDescriptor-s are supported. If a real JavaBeans property of the same name exists, or a fake property of the same name was already assigned earlier, it won't be replaced by the new one by default, however this can be changed with BeansWrapper.MethodAppearanceDecision.setReplaceExistingProperty(boolean).
• If something is exposed as property via BeansWrapper.MethodAppearanceDecision.setExposeAsProperty(PropertyDescriptor) (and not only because it's a real JavaBeans property), and you also want the property value to be accessible in templates as the return value of a 0-argument method of the same name, then call BeansWrapper.MethodAppearanceDecision.setMethodInsteadOfPropertyValueBeforeCall(boolean) with true. Here's an example to explain that. Let's say, you have a class that contains "public String name()", and you exposed that as a property via BeansWrapper.MethodAppearanceDecision.setExposeAsProperty(PropertyDescriptor). So far, you can access the property value from templates as user.name, but user.name() will fail, saying that you try to call a String (because you apply the () operator on the result of user.name, which is a String). But with BeansWrapper.MethodAppearanceDecision.setMethodInsteadOfPropertyValueBeforeCall(boolean) true, both user.name, and user.name() will do the same (which is possible because if user is a MethodCallAwareTemplateHashModel, "name" can be resoled to different values in the two cases). The default (initial) value of methodInsteadOfPropertyValueBeforeCall depends on BeansWrapperConfiguration.setDefaultZeroArgumentNonVoidMethodPolicy(ZeroArgumentNonVoidMethodPolicy), and BeansWrapperConfiguration.setRecordZeroArgumentNonVoidMethodPolicy(ZeroArgumentNonVoidMethodPolicy).
• Prevent the method to hide a JavaBeans property (fake or real) of the same name by calling BeansWrapper.MethodAppearanceDecision.setMethodShadowsProperty(boolean) with false. The default is true, so if you have both a property and a method called "foo", then in the template myObject.foo will return the method itself instead of the property value, which is often undesirable.

Parameters:

in - Describes the method about which the decision will be made.

out - Stores how the method will be exposed in the data-model after process(freemarker.ext.beans.BeansWrapper.MethodAppearanceDecisionInput, freemarker.ext.beans.BeansWrapper.MethodAppearanceDecision) returns. This is initialized so that it reflects the default behavior of BeansWrapper, so you don't have to do anything with this when you don't want to change the default behavior.