Behavior for functions substringBefore and substringAfter are well defined when the string to look for exists. But what happens when the substring is not found? Do they return the whole string or empty string? Code: <p>substringBefore('a.b', '.'): #{fn:substringBefo... Result: substringBefore('a.b', '.'): a substringBef...

You can add custom implicit variables to JSF pages by using a custom EL resolver, in two simple steps: Write an ELResolver class to resolve the variable Add the ELResolver to faces-config.xml Starting from the Maven Hello World example: Add faces API and EL dependencies to pom.xml : <dependencies> <dependency> <groupId>o... Add a simple greeter class ( src/main/java/com/example/Greeter.java ): package com.example; public class Greeter {... Add our custom EL resolver ( src/main/java/com/example/ELResolver.java ): package com.example; import java.util.Itera... Add the custom EL resolver to src/main/resources/META-INF/faces-config.xml <?xml version="1.0" encoding="UTF-8"?> <faces-c... Build JAR with mvn package Drop the JAR into WEB-INF/lib of a webapp and test the new EL with: <h:outputText value="#{Greeter.sayHi('Mike')}"/> Fixed: the setValue method used to throw an exception, which is wrong. @Override public void setValue(ELContext ctx, O......

import java.text.DateFormat; import java.text.S... Output: Date LONG format: November 28, 2011 Date MEDIUM...

My problem is simple: in my XML data, a timestamp is provided as a long integer (number of milliseconds since the "the epoch"). When I do XSLT, I want to display it as a readable string, such as "Mon Nov 01 18:08:48 CDT 2010". After hours of struggle, I found: It's not so easy to get the job done with JDK 1.6 There are tons of garbage on the web in this space (suggestions, code snippets that simply don't work) Simple Xalan extension functions was the only resource that's somewhat informative. Even there some of the examples don't work. Below is a list of what worked and what didn't. This works: <xsl:stylesheet version="1.0" xmlns:xsl="h... This does not (providing long value to Date constructor): <xsl:stylesheet version="1.0" xmlns:xsl="h......

This is an example that uses tag handler, UI component and renderer together to support a custom taglib. The main purpose is to show how these components play together. The tag renders <ui:param name="extra" value="el interpreted"/> ... as <h3>my:foreach</h3> <ul class="css class" extra... These are the files: The tag handler ( src/main/java/com/example/ForeachTagHandler.java ): package com.example; import java.util.Map; ... The UI component ( src/main/java/com/example/UIForeach.java ): package com.example; import java.io.IOExcep... The renderer ( src/main/java/com/example/ForeachRenderer.java ): package com.example; import java.io.IOExcep... Faces config ( src/main/resources/META-INF/faces-config.xml ): <?xml version="1.0" encoding="UTF-8"?> <faces-c... Taglib config ( src/main/resources/META-INF/foreach.taglib.xml ): <?xml version="1.0" encoding="UTF-8"?> <facelet...

The improved custom taglib works with existing facelet ui taglibs. For example: <ui:param name="theName" value="John"/> <my:hel... produces the expected output. However, a problem exists with the ui:repeat tag: <h3>With ui:repeat</h3> <ui:repeat var="theName... When tested with a URL like: http://localhost:8080/facelet-demo/?name=Zack&name... the raw EL prints out the correct names, but my custom tag substitutes empty string for theName2 ! In theory, the response is rendered in the Render Response phase, way after the Apply Request Values phase, actual values should be available to EL. The answer to this anomaly turned out to be very deep ! Yes, right there in the code! I would consider this a bug in facelets implementation, but the JSF spec did not tell what the expected behavior should be. In my custom...

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:...

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:...

Experts may disagree but I found it absolutely stunning that JSF EL does not provide an operator for string concatenation. The Java "+" operator is there for the take. Java, which is a strongly typed compiled language, overloads the "+" operator in such a way that any object can be concatenated with a string. But JSF EL, which definitely isn't as strongly typed as Java, restricts the "+" operator to numerical values only! Of course, experts may argue that the "+" operator overloading is a huge design flaw of the Java language. But even so, JSF EL is not the right place to fix it! In some cases, a concatenation operator isn't needed, for example: <ui:repeat var="tab" value="#{tabs}"> <img ... But in case the concatenated...

This is an example to replace a Java string with case insensitive match. Code: public class ReplaceTest { public static vo... Output: Done TEST tEst tESt Test Test TEST tEst tESt Te...