| ////////////////////// |
| * 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. |
| ////////////////////// |
| |
| [[core-api-layer,Layer]] |
| = Layer = |
| A Polygene™ Application must consist of at least one layer. More layers are common, often dividing the application along the |
| common architectural diagrams used on whiteboards, perhaps with a UI layer at the top, followed by a service or application |
| layer, then with a domain layer and finally some persistence layer at the bottom. |
| |
| Polygene™ enforces this layering by requiring the <<core-bootstrap-assembly>> to declare which layer uses which other layer. And |
| <<core-api-visibility>> rules define that layers below can not locate composites in layers above. Also, defining that |
| "Layer1 uses Layer2" and "Layer2 uses Layer3" does NOT imply that Layer1 has <<core-api-visibility>> to Layer3. If that |
| is wanted, then it must be declared explicitly. |
| |
