| // 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; |
| |
| /** |
| * A wrapper around {@link org.apache.tapestry5.Translator} that combines the translator for a specific {@link |
| * org.apache.tapestry5.Field} and (sometimes) an override of the default validation message (used when an input value |
| * can't be parsed). |
| */ |
| public interface FieldTranslator<T> |
| { |
| /** |
| * Returns the type of the server-side value. |
| * |
| * @return a type |
| */ |
| Class<T> getType(); |
| |
| /** |
| * Invoked after the client-submitted value has been {@link Translator translated} to check that the value conforms |
| * to expectations (often, in terms of minimum or maximum value). If and only if the value is approved by all |
| * Validators is the value applied by the field. |
| * |
| * @throws ValidationException if the value violates the constraint |
| */ |
| T parse(String input) throws ValidationException; |
| |
| /** |
| * Converts a server-side value to a client-side string. This allows for formatting of the value in a way |
| * appropriate to the end user. |
| * |
| * @param value the server side value (which will not be null) |
| * @return client-side value to present to the user |
| * @see Translator#toClient(Object) |
| */ |
| String toClient(T value); |
| |
| /** |
| * Invokes {@link Translator#render(Field, String, MarkupWriter,org.apache.tapestry5.services.FormSupport)}. This is |
| * called at a point "inside" the tag, so that additional attributes may be added. In many cases, the underlying |
| * {@link org.apache.tapestry5.Validator} may write client-side JavaScript to enforce the constraint as well. |
| * |
| * @param writer markup writer to direct output to. |
| * @see org.apache.tapestry5.MarkupWriter#attributes(Object[]) |
| */ |
| void render(MarkupWriter writer); |
| } |