Velocity

Apache Velocity is a server-side templating language used in Confluence to render page content. It enables integration of Java objects within standard HTML, making it a powerful tool for user macros.

Key Characteristics

Designed to dynamically generate content by combining static text with variable references, directives, and expressions.
Highly flexible, allowing developers to integrate it with various data sources and Java objects. It supports custom tools, macros, and user-defined directives.

Syntax Basics

Below are some common Velocity syntax elements used in Confluence:

Element	Syntax	Example
Variable reference	`$variableName`	$foo
Variable assignment	`#set ($var = value)`	#set ($message = "Hello")
Conditional statements	`#if ... #else ... #end`	#if ($message == "Hello") Message is Hello #end
Loops	`#foreach ($item in $collection) ... #end` `#break` `#stop`	#foreach ($user in $users) $user <br> #end #foreach ($item in $items) #if ($item == "stop") #break ##if ($error) rror) #stop #end
Quiet notation	`$!variable`	#set($name = "Kevin") Hello, $name! ## Output: Hello, Kevin! Hello, $unknown! ## Output: Hello, $unknown! Hello, $!unknown! ## Output: Hello, ! (avoids rendering the output literally)

To learn more about Velocity, please see the Velocity user guide.

Handling Null Values

{"timestamp":1792799680505,"msg":"A unknown Exception Occurred","errorMsg":"The provided AtlassianHostUser did not specify a user to act as.","code":"500"}