// Copyright 2011 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.plastic;

/**
 * Defines per-instance context values for a transformed PlasticClass.
 */
public interface InstanceContext
{
    /**
     * Returns the type of the instance created with this context. This is most often of interest
     * to implementations of {@link ComputedValue}.
     */
    Class<?> getInstanceType();

    /**
     * Gets an instance context value which is identified by type.
     * 
     * @throws IllegalArgumentException
     *             if no such value is available in the context.
     */
    <T> T get(Class<T> valueType);
}
