This facelet fragment will never print anything: <ui:repeat var="person" value="#{myBean.theJTeam}"... because the test condition always returns false, even though the person var is not null. The same happens even when I define another variable with ui:param : <ui:repeat var="person" value="#{myBean.theJTeam}"... What's happening? The c:if test condition is evaluated before the ui:repeat tag had a chance to set the value! Both facelet ui tags and JSTL c tags are evaluated at the Render Response phase of the JSF lifecycle. But within the Render Response cycle, there are two sub-phases (so to speak): the first builds the UI element tree, the second renders the UI tree. The JSTL c:if tag is evaluated when the tree is built, but the facelet ui:repeat tag is evaluated when the UI...

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:...

The String.format() method provides versatile formatting capabilities. This tutorial tries to present these capabilities in a accessible manner. The format string A format string can contain zero, one, or more format specifiers . The general form of a format specifier is: %[argument_index$] [flags] [width] [.precision]co... where things in square brackets are optional, and conversion is a character indicating the conversion to be applied to the corresponding variable value. The only required characters in the format specifier is the percent sign % and the conversion character. A simple example: public static void simpleFormat() { System.out... The Argument index The argument index is specified by a number, terminated by the dollar sign $ . The same argument may be repeated multiple times in a format string. Unindexed...

Check the __name__ variable to see if the Python module was invoked from the command line. The line prints when the Python script is called from the command line, but doesn't print when it is imported by another Python module with import MyModule . if __name__ == '__main__': print 'Invoked f...

Use print_r to print out variables in human readable form. <?php $a = array ('a' => 'apple', 'b' => 'banan... Prints: Plain print: ============ Array print...

The Unix shell passes these parameters to the shell script: Variable Meaning $* A single string representing all command line arguments separated by $IFS (internal field separator, usually a space) $@ A sequence of strings representing the command line arguments. $1,$2...$n $1 is the first argument, $2 is the second argument, and so on... $0 The name of the script itself. $# The number of arguments. Example shell script ( sharg.sh ): #!/bin/sh echo $# arguments passed to $0: $@ ... Output for ./sharg.sh "a b c d" : 1 arguments passed to ./sharg.sh: a b c d here ... Output for ./sharg.sh a "b c" d : 3 arguments passed to ./sharg.sh: a b c d here ...

By the perldoc , use Module LIST; is exactly equivalent to: BEGIN { require Module; Module->import( LIST); } Because of the BEGIN block, use is executed immediately. Therefore, it is not suitable for lazy loading of modules at runtime. use does not work with a runtime variable: C:\>perl $cgi = "CGI"; require $cgi; prin... require works: C:\>perl $cgi = 'CGI'; require "${cgi}.pm"; ... Also, file extension is required if require is not passed a bareword: // this works require CGI; // so does th...

Perl package variables are accessed with the expression: $PackageName::variableName (for scalar, similarly for vector etc), not PackageName::$VariableName . Example: C:\>perl use CGI; print $CGI::VERSION; ^Z...

You can use the eval function to substitute a value defined by a variable. Suppose you have a string literal $a = 'a $string' and you want Perl to substitute $string with the value of the $string variable. This is normally not a problem. Because if you use double quote, Perl does the interpretation automatically: $string = 'theactual'; $a = "a $string"; pri... But this doesn't work if the value of $string isn't available when you define the template $a . In this case, you have to use single quote to preserve the template definition. But you can use eval to do the replacement when the value of $string becomes available: #!/usr/bin/perl $a = 'a $string'; $string = ...

In the Perl for (foreach) loop, the looping variable is actually an alias (reference) to the original variable. Therefore, any changes applied to that variable are reflected in the original variable: C:\>perl @a = ('1', '2', '3'); for my $i (@a... This trick can be used to trim a Perl string: C:\>perl $s = ' abcd '; for ($s){ ...