| // Copyright 2009 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; |
| |
| /** |
| * Extension to {@link org.apache.tapestry5.Asset} that adds a method to determine if the asset is invariant or not. |
| * {@link org.apache.tapestry5.services.AssetFactory} instances should ideally return Asset2 objects, not Asset. This is |
| * only of primary interest to the {@link org.apache.tapestry5.internal.bindings.AssetBindingFactory}, as it determines |
| * the invariance of the binding from the asset (and assumes variant unless the asset object implements this |
| * interface). |
| * |
| * @since 5.1.0.0 |
| */ |
| public interface Asset2 extends Asset |
| { |
| /** |
| * Returns true if the Asset is invariant (meaning that it returns the same value from {@link Asset#toClientURL()} |
| * at all times). Most Assets are invariant. Assets that are used as binding values will be cached more aggressively by Tapestry if they are |
| * invariant. |
| * |
| * @return true if invariant |
| * @see org.apache.tapestry5.services.AssetPathConverter#isInvariant() |
| * @see Binding#isInvariant() |
| */ |
| boolean isInvariant(); |
| } |
