| // Copyright 2008 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.services; |
| |
| /** |
| * Provides efficient, cached access to an environmental object. |
| * |
| * @param <T> |
| * @see org.apache.tapestry5.services.Environment#getAccess(Class) |
| * @since 5.0.19 |
| * @deprecated No longer gives a performance advantage due to pool-less pages |
| */ |
| public interface EnvironmentalAccess<T> |
| { |
| |
| /** |
| * Peeks at the current top of the configured type's stack. |
| * |
| * @return current value of type, or null. |
| */ |
| T peek(); |
| |
| /** |
| * Peeks at the current top of the configured type's stack. |
| * |
| * @return the current value |
| * @throws RuntimeException if no environmental of that type has been added |
| */ |
| T peekRequired(); |
| } |
