// Copyright 2008, 2010 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.apache.tapestry5;
/**
* A collection of parameters that may eventually be passed to an event handler method. Includes the
* ability to coerce
* or encode parameters as needed.
*
* @see org.apache.tapestry5.ioc.services.TypeCoercer
* @see org.apache.tapestry5.ValueEncoder
*/
public interface EventContext
{
/**
* Returns the number of parameter values that can be extracted.
*/
int getCount();
/**
* Extracts a parameter value and coerces or decodes it to the desired type.
*
* @param desiredType
* the type of value required
* @param index
* identifies which parameter value to extract
* @return the value extracted and converted or coerced
* @throws RuntimeException
* if the value can't be converted or the index is out of range
*/
<T> T get(Class<T> desiredType, int index);
/**
* Extracts the value of each context value as a string.
*
* @return context values
* @since 5.2.0
*/
String[] toStrings();
}