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Created by zhidao on April 25, 2012 14:56:38
Last update: April 25, 2012 14:56:38
Lacking better alternatives, this is how I render a global validation error:
<spring:bind path="changePasswordForm">
<c:if ...
<form:errors> without path attribute seems to work too:
<form:errors cssClass="ui-error"/>
Created by Fang on March 06, 2012 12:25:33
Last update: March 06, 2012 12:25:33
In the bean validation API javadoc, for every constraint annotation, there's a corresponding .List annotation. For example, for @NotNull , there's @NotNull.List , for which JavaDoc says: Defines several @NotNull annotations on the same element What would you accomplish with multiple @NotNull annotations that you cannot accomplish with one @NotNull ? This is a test to reveal some of the facts. Change the Person class to:
package com.example; public class Person { ... Add another JUnit test ( src/test/com/example/TestPersonWithList.java ): package com.example; import java.util.Itera... As the test shows, a Person bean can never be valid because we are requiring that name must begin with Mr and Ms . One might think that the same can be accomplished by simply repeating the @Pattern annotation multiple times,...
Created by Fang on February 27, 2012 12:19:19
Last update: February 27, 2012 12:19:19
Mapping Java objects to Jackson JSON is pretty simple. But if you name a JSON field wrong, you'll get the "Unrecognized field ... (Class ...), not marked as ignorable" error. The rule for mapping a Java bean attribute name to a JSON field name is: lower all leading capital letters until the first lower case letter .
For example, this Java class:
package com.example;
public class Person {
...
maps to this JSON string:
{
"firstName": "Jane",
"lastName": "...
Test code:
package com.example;
import java.net.URL;
...
Created by Fang on December 03, 2011 12:31:20
Last update: December 03, 2011 12:33:23
The <h:outputText> tag generates different output for body text and value attribute. I tested the following with Apache MyFaces 2.1.3:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Stric...
With value attribute, the output was:
<table border='1' cellspacing='0' cellpadding='4'>...
With text in body, the output was (i.e., the text was escaped despite escape="false" ):
<table border='1' cellspacing='0' cellpadding='...
Created by Fang on November 08, 2011 20:55:00
Last update: November 21, 2011 18:19:44
In the simple taglib example , I used a tag handler class to implement a taglib. This is an example to implement a taglib with a UI component. The purpose is to use a custom tag to split a string and print each part in a separate paragraph, i.e., print
<p>john</p> <p>steve</p> <p>mike</p> with custom tag <my:foreach> : <my:foreach var="who" value="john steve mike"> ... These are the files: pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0"... src/main/java/com/example/UIForeash.java : package com.example; import java.io.IOExcep... src/main/resources/META-INF/faces-config.xml : <?xml version="1.0" encoding="UTF-8"?> <faces-c... src/main/resources/META-INF/foreach.taglib.xml : <?xml version="1.0" encoding="UTF-8"?> <facelet... How to use: Put the JAR file generated by the above project in the WEB-INF/lib folder of the web app. If the web app is a Maven project, just add the taglib project as a dependency:...
Created by Fang on November 21, 2011 13:49:11
Last update: November 21, 2011 13:49:11
In the test for the simple taglib example , I used a literal string for the name attribute:
<my:hello name="Jack"/> What happens if the name attribute contains EL expresson? For example: <my:hello name="#{param['name']}"/> If EL works, the tag should take the value of the " name " request parameter and print it out. But the tag as implemented in the simple taglib example prints the literal string: Hello #{param['name']}! I am FaceletTag. In order to make a tag to recognize EL, we have to use TagAttribute.getValue(FaceletContext ctx) instead of TagAttribute.getValue() . The latter returns the literal value of the attribute. The HelloTagHandler should be changed to: package com.example; import java.io.IOExcep... Rebuild the taglib and test with a URL like this: http://localhost:8080/facelet-test/?name=Jack The tag will print:...
Created by Dr. Xi on November 11, 2011 10:05:22
Last update: November 11, 2011 10:12:01
This is an HTML image tag filter using Java regex. It takes a string, finds the img tags, replaces the src attribute with one provided by the filter, then adds a class name to the class attribute.
import java.util.regex.*;
import java.io.*;
...
Test file:
<div id="HTML snippet">
<img src="img/big/txt-m...
Created by Fang on October 30, 2011 20:35:17
Last update: October 30, 2011 20:37:03
This note lists some of the different behaviors I found using different JSF implementations. In the simple JSF facelet example, I used Sun's reference implementation version 2.0.0-RC:
<dependency> <groupId>javax.faces</gro... With this version, the DOCTYPE declaration is dropped when the page is rendered. It doesn't matter what DOCTYPE you declare in your templates, the facelet engine simply drops it. The problem with this is, your page is always displayed in quirks mode , despite your intentions to require standards compliant mode. The DOCTYPE problem is fixed in release 2.0.2-FCS . Change the dependency in pom.xml to: <dependency> <groupId>javax.faces</gro... and test again, you'll find that DOCTYPE is faithfully passed over to the browser (view source at browser). You can delete the DOCTYPE declaration in the xhtml template...
Created by James on May 01, 2011 20:46:46
Last update: May 01, 2011 20:46:46
Unlike languages such as Python or PHP, an empty array in JavaScript is true . The proper way to test for an empty array is to check the length attribute:
// empty array is true
var anArray = [];
if ...
Created by jinx on April 17, 2011 20:40:12
Last update: April 17, 2011 20:40:56
For JavaScript in the <script> block or JavaScript included with a src attribute: nothing more is needed than escaping the single quote or double quote - depending on how the JavaScript string is quoted.
Example:
var a = 'My name is <?php echo str_replace('\'', '...
For inline JavaScript, escape HTML special characters :
<?php
echo '<a href="test" onclick="alert(\...
