001package org.gwtbootstrap3.client.ui.form.error; 002 003/* 004 * #%L 005 * GwtBootstrap3 006 * %% 007 * Copyright (C) 2015 GwtBootstrap3 008 * %% 009 * Licensed under the Apache License, Version 2.0 (the "License"); 010 * you may not use this file except in compliance with the License. 011 * You may obtain a copy of the License at 012 * 013 * http://www.apache.org/licenses/LICENSE-2.0 014 * 015 * Unless required by applicable law or agreed to in writing, software 016 * distributed under the License is distributed on an "AS IS" BASIS, 017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 018 * See the License for the specific language governing permissions and 019 * limitations under the License. 020 * #L% 021 */ 022 023import java.util.List; 024 025import org.gwtbootstrap3.client.ui.HelpBlock; 026import org.gwtbootstrap3.client.ui.base.HasValidationState; 027import org.gwtbootstrap3.client.ui.base.ValueBoxBase; 028import org.gwtbootstrap3.client.ui.constants.ValidationState; 029 030import com.google.gwt.editor.client.EditorError; 031import com.google.gwt.event.logical.shared.AttachEvent; 032import com.google.gwt.event.logical.shared.AttachEvent.Handler; 033import com.google.gwt.user.client.ui.HasWidgets; 034import com.google.gwt.user.client.ui.Widget; 035 036/** 037 * This is the default {@link ErrorHandler} implementation. The assumption is that every {@link ValueBoxBase} 038 * instance will have a {@link HasValidationState} parent. If there is a {@link HelpBlock} that is a child of 039 * the {@link HasValidationState} parent then error messages will be displayed in the {@link HelpBlock}. 040 * 041 * Example: 042 * 043 * <pre>{@code 044 * <b:FormGroup> 045 * <b:FormLabel for="username">User</b:FormLabel> 046 * <b:TextBox b:id="username" ui:field="username" /> 047 * <b:HelpBlock iconType="EXCLAMATION" /> 048 * </b:FormGroup> 049 * }</pre> 050 * 051 * @author Steven Jardine 052 */ 053public class DefaultErrorHandler implements ErrorHandler { 054 055 private boolean initialized = false; 056 057 private final Widget inputWidget; 058 059 private HelpBlock validationStateHelpBlock = null; 060 061 private HasValidationState validationStateParent = null; 062 063 /** 064 * Default error handler. 065 * 066 * @param parent the parent of this error handler. 067 */ 068 public DefaultErrorHandler(Widget widget) { 069 super(); 070 assert widget != null; 071 this.inputWidget = widget; 072 this.inputWidget.addAttachHandler(new Handler() { 073 @Override 074 public void onAttachOrDetach(AttachEvent event) { 075 init(); 076 } 077 }); 078 } 079 080 /** {@inheritDoc} */ 081 @Override 082 public void cleanup() { 083 } 084 085 /** {@inheritDoc} */ 086 @Override 087 public void clearErrors() { 088 if (validationStateParent == null) { return; } 089 validationStateParent.setValidationState(ValidationState.NONE); 090 if (validationStateHelpBlock != null) { validationStateHelpBlock.clearError(); } 091 } 092 093 /** 094 * Find the sibling {@link HelpBlock}. 095 * 096 * @param widget the {@link Widget} to search. 097 * @return the found {@link HelpBlock} of null if not found. 098 */ 099 private HelpBlock findHelpBlock(Widget widget) { 100 if (widget instanceof HelpBlock) { return (HelpBlock) widget; } 101 // Try and find the HelpBlock in the children of the given widget. 102 if (widget instanceof HasWidgets) { 103 for (Widget w : (HasWidgets) widget) { 104 if (w instanceof HelpBlock) { return (HelpBlock) w; } 105 } 106 } 107 if (!(widget instanceof HasValidationState)) { 108 // Try and find the HelpBlock in the parent of widget. 109 return findHelpBlock(widget.getParent()); 110 } 111 return null; 112 } 113 114 /** 115 * Initialize the instance. We find the parent {@link HasValidationState} and sibling {@link HelpBlock} 116 * only 1 time on initialization. 117 */ 118 public void init() { 119 if (initialized) { return; } 120 Widget parent = inputWidget.getParent(); 121 while (parent != null && !parent.getClass().getName().equals("com.google.gwt.user.client.ui.Widget")) { 122 if (parent instanceof HasValidationState) { 123 validationStateParent = (HasValidationState) parent; 124 validationStateHelpBlock = findHelpBlock(inputWidget); 125 break; 126 } 127 parent = parent.getParent(); 128 } 129 if (inputWidget.isAttached() || validationStateParent != null) { 130 initialized = true; 131 } 132 } 133 134 /** {@inheritDoc} */ 135 @Override 136 public void showErrors(List<EditorError> errors) { 137 init(); 138 // clearErrors(); 139 String errorMsg = ""; 140 if (validationStateParent != null) { 141 validationStateParent.setValidationState(errors.size() <= 0 ? ValidationState.NONE : ValidationState.ERROR); 142 for (int index = 0; index < errors.size(); index++) { 143 errorMsg = errors.get(0).getMessage(); 144 if (index + 1 < errors.size()) { errorMsg += "; "; } 145 } 146 } 147 if (validationStateHelpBlock != null) { 148 validationStateHelpBlock.setError(errorMsg); 149 } 150 } 151 152}