| // Copyright 2010 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.corelib.components; |
| |
| import org.apache.tapestry5.BindingConstants; |
| import org.apache.tapestry5.CSSClassConstants; |
| import org.apache.tapestry5.Field; |
| import org.apache.tapestry5.MarkupWriter; |
| import org.apache.tapestry5.ValidationTracker; |
| import org.apache.tapestry5.annotations.Environmental; |
| import org.apache.tapestry5.annotations.HeartbeatDeferred; |
| import org.apache.tapestry5.annotations.Parameter; |
| import org.apache.tapestry5.corelib.internal.InternalMessages; |
| import org.apache.tapestry5.dom.Element; |
| |
| /** |
| * Presents validation errors of a single field. Must be enclosed by a |
| * {@link org.apache.tapestry5.corelib.components.Form} component. |
| * |
| * @since 5.2.0 |
| */ |
| public class Error |
| { |
| /** |
| * The for parameter is used to identify the {@link Field} to present errors of. |
| */ |
| @Parameter(name = "for", required = true, allowNull = false, defaultPrefix = BindingConstants.COMPONENT) |
| private Field field; |
| |
| /** |
| * The CSS class for the div element rendered by the component. The default value is "t-error-single". |
| */ |
| @Parameter(name = "class") |
| private String className = CSSClassConstants.ERROR_SINGLE; |
| |
| @Environmental(false) |
| private ValidationTracker tracker; |
| |
| void beginRender(final MarkupWriter writer) |
| { |
| if (tracker == null) |
| throw new RuntimeException(InternalMessages.encloseErrorsInForm()); |
| |
| Element element = writer.element("div"); |
| |
| updateElement(element); |
| |
| writer.end(); |
| } |
| |
| @HeartbeatDeferred |
| private void updateElement(final Element element) |
| { |
| final String error = tracker.getError(field); |
| |
| if (error == null) |
| { |
| element.remove(); |
| } |
| else |
| { |
| element.forceAttributes("class", className); |
| element.text(error); |
| } |
| } |
| |
| } |