// --------------------------------------------------------------------------
// Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// Neither the name of the Drew Davidson nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
// OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
// AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
// DAMAGE.
// --------------------------------------------------------------------------
package ognl;
import java.util.
Map;
/**
* This interface defines methods for setting and getting a property from a target object. A
* "property" in this case is a named data value that takes the generic form of an Object---the same
* definition as is used by beans. But the operational semantics of the term will vary by
* implementation of this interface: a bean-style implementation will get and set properties as
* beans do, by reflection on the target object's class, but other implementations are possible,
* such as one that uses the property name as a key into a map.
* <p>
* An implementation of this interface will often require that its target objects all be of some
* particular type. For example, the MapPropertyAccessor class requires that its targets all
* implement the java.util.Map interface.
* <p>
* Note that the "name" of a property is represented by a generic Object. Some implementations may
* require properties' names to be Strings, while others may allow them to be other types---for
* example, ArrayPropertyAccessor treats Number names as indexes into the target object, which must
* be an array.
*
* @author Luke Blanshard (blanshlu@netscape.net)
* @author Drew Davidson (drew@ognl.org)
*/
public interface
PropertyAccessor
{
/**
* Extracts and returns the property of the given name from the given target object.
*
* @param context
* The current execution context.
* @param target
* the object to get the property from
* @param name
* the name of the property to get.
*
* @return the current value of the given property in the given object
* @exception OgnlException
* if there is an error locating the property in the given object
*/
Object getProperty(
Map context,
Object target,
Object name)
throws
OgnlException;
/**
* Sets the value of the property of the given name in the given target object.
*
* @param context
* The current execution context.
* @param target
* the object to set the property in
* @param name
* the name of the property to set
* @param value
* the new value for the property.
*
* @exception OgnlException
* if there is an error setting the property in the given object
*/
void
setProperty(
Map context,
Object target,
Object name,
Object value)
throws
OgnlException;
/**
* Returns a java string representing the textual method that should be called to access a
* particular element. (ie "get")
*
* @param context
* The current execution context.
* @param target
* The current object target on the expression tree being evaluated.
* @param index
* The index object that will be placed inside the string to access the value.
*
* @return The source accessor method to call.
*/
String getSourceAccessor(
OgnlContext context,
Object target,
Object index);
/**
* Returns a java string representing the textual method that should be called to set a
* particular element. (ie "set")
*
* @param context
* The current execution context.
* @param target
* The current object target on the expression tree being evaluated.
* @param index
* The index object that will be placed inside the string to set the value.
* @return The source setter method to call.
*/
String getSourceSetter(
OgnlContext context,
Object target,
Object index);
}