org.springframework.extensions.surf.extensibility.impl

Class AbstractFreeMarkerDirective

java.lang.Object

org.springframework.extensions.surf.extensibility.impl.AbstractFreeMarkerDirective

All Implemented Interfaces:

freemarker.template.TemplateDirectiveModel, freemarker.template.TemplateModel

Direct Known Subclasses:

AbstractExtensibilityDirective

public abstract class AbstractFreeMarkerDirective
extends Object
implements freemarker.template.TemplateDirectiveModel

Should be extended to take advantage of the helper methods it provides for retrieving properties required for the directive represented by the subclass. Extending this class and using the helper methods will prevent unnecessary duplication of code.

The helper methods provided are initially for finding properties and ensuring that they are of the expected type, although more methods could be provided in the future.

Author:

David Draper

Field Summary

Fields inherited from interface freemarker.template.TemplateModel

NOTHING

Constructor Summary

Constructors

Constructor and Description
AbstractFreeMarkerDirective(String directiveName) This constructor will need to invoked by subclasses and ensures that a directive name is provided.

Method Summary

Modifier and Type	Method and Description
protected boolean	getBooleanProperty(Map<String,Object> params, String targetProp, boolean required) Attempts to retrieve a boolean property from the map of parameters supplied using the key provided.
String	getDirectiveName()
protected String	getStringProperty(Map<String,Object> params, String targetProp, boolean required) Attempts to retrieve a String property from the map of parameters supplied using the key provided.

Methods inherited from class java.lang.Object

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

Methods inherited from interface freemarker.template.TemplateDirectiveModel

execute

Constructor Detail

AbstractFreeMarkerDirective

public AbstractFreeMarkerDirective(String directiveName)

This constructor will need to invoked by subclasses and ensures that a directive name is provided. The directive name is used in exception messages to assist debugging.

Parameters:

directiveName - The name of the directive represented by the subclass.

Method Detail

getDirectiveName

public String getDirectiveName()

getStringProperty

protected String getStringProperty(Map<String,Object> params,
                                   String targetProp,
                                   boolean required)
                            throws freemarker.template.TemplateModelException

Attempts to retrieve a String property from the map of parameters supplied using the key provided.

• If a property is found but it is not a String then an exception will be thrown.
• If a property is not found and not required then null will be returned.
• If a property is not found and is required then an exception will be thrown

Parameters:

params - A map of parameters (this is supplied to the execute method that must be implemented by subclasses.

targetProp - The name of the property to attempt to retrieve.

required - Indicates whether or not the property is required for the directive to process successfully.

Returns:

A String value for the property name supplied (or null if it could not be found)

Throws:

freemarker.template.TemplateModelException - When a property matching the supplied name is found but is not a String.

getBooleanProperty

protected boolean getBooleanProperty(Map<String,Object> params,
                                     String targetProp,
                                     boolean required)
                              throws freemarker.template.TemplateModelException

Attempts to retrieve a boolean property from the map of parameters supplied using the key provided.

• If a property is found but it is not a boolean then an exception will be thrown.
• If a property is not found and not required then false will be returned.
• If a property is not found and is required then an exception will be thrown

Parameters:

params - A map of parameters (this is supplied to the execute method that must be implemented by subclasses.

targetProp - The name of the property to attempt to retrieve.

required - Indicates whether or not the property is required for the directive to process successfully.

Returns:

A boolean value for the property name supplied (or false if it could not be found)

Throws:

freemarker.template.TemplateModelException - When a property matching the supplied name is found but is not a boolean.