001 // Copyright 2004, 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. 014 015 package org.apache.tapestry.valid; 016 017 import org.apache.tapestry.IRender; 018 import org.apache.tapestry.form.IFormComponent; 019 020 /** 021 * Defines the interface for an object that tracks input fields. This interface is now poorly named, 022 * in that it tracks errors that may <em>not</em> be associated with a specific field. 023 * <p> 024 * For each field, a flag is stored indicating if the field is, in fact, in error. The input 025 * supplied by the client is stored so that if the form is re-rendered (as is typically done when 026 * there are input errors), the value entered by the user can be displayed back to the user. An 027 * error message renderer is stored; this is an object that can render the error message (it is 028 * usually a {@link org.apache.tapestry.valid.RenderString} wrapper around a simple string). 029 * 030 * @author Howard Lewis Ship 031 * @since 1.0.8 032 */ 033 034 public interface IFieldTracking 035 { 036 /** 037 * Returns true if the field is in error (that is, if it has an error message 038 * {@link #getErrorRenderer() renderer}. 039 */ 040 041 public boolean isInError(); 042 043 /** 044 * Returns the field component. This may return null if the error is not associated with any 045 * particular field. Note: may return null after the field tracking object is serialized and 046 * deserialized (the underlying component reference is transient); this metehod is primarily 047 * used for testing. 048 */ 049 050 public IFormComponent getComponent(); 051 052 /** 053 * Returns an object that will render the error message. The renderer <em>must</em> implement 054 * a simple <code>toString()</code> that does not produce markup, but is a simple message. 055 * 056 * @see ValidatorException#ValidatorException(String, IRender, ValidationConstraint) 057 * @since 1.0.9 058 */ 059 060 public IRender getErrorRenderer(); 061 062 /** 063 * Returns the invalid input recorded for the field. This is stored so that, on a subsequent 064 * render, the smae invalid input can be presented to the client to be corrected. 065 */ 066 067 public String getInput(); 068 069 /** 070 * Returns the name of the field, that is, the name assigned by the form (this will differ from 071 * the component's id when any kind of looping operation is in effect). 072 */ 073 074 public String getFieldName(); 075 076 /** 077 * Returns the validation constraint that was violated by the input. This may be null if the 078 * constraint isn't known. 079 */ 080 081 public ValidationConstraint getConstraint(); 082 }