| // Copyright 2004 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.tapestry.valid; |
| |
| import org.apache.tapestry.IMarkupWriter; |
| import org.apache.tapestry.IRequestCycle; |
| import org.apache.tapestry.form.IFormComponent; |
| |
| /** |
| * An object that works with an {@link IFormComponent} to format output |
| * (convert object values to strings values) and to process input |
| * (convert strings to object values and validate them). |
| * |
| * @author Howard Lewis Ship |
| * @version $Id$ |
| * @since 1.0.8 |
| * |
| **/ |
| |
| public interface IValidator |
| { |
| /** |
| * All validators must implement a required property. If true, |
| * the client must supply a non-null value. |
| * |
| **/ |
| |
| public boolean isRequired(); |
| |
| /** |
| * Invoked during rendering to convert an object value (which may be null) |
| * to a String. It is acceptible to return null. The string will be the |
| * VALUE attribute of the HTML text field. |
| * |
| **/ |
| |
| public String toString(IFormComponent field, Object value); |
| |
| /** |
| * Converts input, submitted by the client, into an object value. |
| * May return null if the input is null (and the required flag is false). |
| * |
| * <p>The input string will already have been trimmed. It may be null. |
| * |
| * @throws ValidatorException if the string cannot be converted into |
| * an object, or the object is |
| * not valid (due to other constraints). |
| **/ |
| |
| public Object toObject(IFormComponent field, String input) throws ValidatorException; |
| |
| /** |
| * Invoked by the field after it finishes rendering its tag (but before |
| * the tag is closed) to allow the validator to provide a contribution to the |
| * rendering process. Validators typically generated client-side JavaScript |
| * to peform validation. |
| * |
| * @since 2.2 |
| * |
| **/ |
| |
| public void renderValidatorContribution( |
| IFormComponent field, |
| IMarkupWriter writer, |
| IRequestCycle cycle); |
| |
| } |