Velocity¶

• Table of contents
• Velocity
  • Easy templating language for the non geek
  • Details
    • $ (dollar sign) = a variable
    • . (dot) = object notation
    • ! (exclamation mark) = the silent mark
    • ! (exclamation mark) = negation
    • # (hash symbol) = velocity directive

Easy templating language for the non geek¶

Velocity is the world's easiest templating tool.

Using it within HTML helps to clearly separate your presentation from your business logic, and a "report designer" or "web page designer" will only need to learn 4 special characters: $ ! . # (that's no swearing ;-)

And as a developer, you will only need to learn a grand total of 9 directives to use the full power of Velocity in your own reports.

Details¶

$ (dollar sign) = a variable¶

A dollar sign in front of a word (of any length) instructs Velocity that this word is in fact a variable.
Variables are replaced with content that you provide from within Servoy.

Examples of valid variables are:

• $foundset
• $my_chart1
• $myVeryLongVariableNameHere

. (dot) = object notation¶

Standard object notation allow for accessing object properties and methods, just like Servoy, and with any Servoy variables.

For example:

• $foundset.id
• $rec.relation_to_child.name
• $dataset.oneField
  etc.

! (exclamation mark) = the silent mark¶

If you are unsure whether or not a variable will exist at runtime (it might be null), you can use the ! exclamation mark to tell Velocity not to output anything.
For example:

• $!foundset
• $!my_chart1
• $!myVeryLongVariableNameHere

! (exclamation mark) = negation¶

The ! exclamation mark can also be used as a negation in tests, for example:
#if(!$test)
// do something
#end

# (hash symbol) = velocity directive¶

The # hash symbol is reserved for denoting Velocity directives. These directives are self-explanatory and are listed below:

• #if
• #else
• #elseif
• #end
• #set
• #foreach
• #include
• #parse
• #macro

Note: Velocity also provides a means for you to create special functions and use them as macros anywhere in your templates.

Check the velocity user guide to know more about some extended options:
http://velocity.apache.org/engine/releases/velocity-1.7/user-guide.html