001// Copyright 2005 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry.form; 016 017import org.apache.tapestry.IMarkupWriter; 018import org.apache.tapestry.IRequestCycle; 019import org.apache.tapestry.valid.ValidatorException; 020 021/** 022 * Implements the logic used by {@link RequiredField}s for required field checking on rewind and 023 * generating client-side logic during render. 024 * 025 * @author Paul Ferraro 026 * @since 4.0 027 */ 028public interface ValidatableFieldSupport 029{ 030 /** 031 * Called during render of the specified component. Renders any contributions from validators. 032 */ 033 public void renderContributions(ValidatableField field, IMarkupWriter writer, 034 IRequestCycle cycle); 035 036 /** 037 * Called during rewind of the specified component. Specified value is validated using the 038 * component's validators. 039 * 040 * @throws ValidatorException if validation fails 041 */ 042 public void validate(ValidatableField component, IMarkupWriter writer, IRequestCycle cycle, Object value) throws ValidatorException; 043 044 /** 045 * Returns true if this component is required. This usually entails a search of the component's 046 * validators. 047 */ 048 public boolean isRequired(ValidatableField field); 049}