Sys.Eval() is used to execute Viper expressions. You can use it in situations where you need to execute an expression in a viper.

Since a viper must always be enclosed with a method call, you will sometimes need a wrapping method:

Smartsite SXML	Copy Code
{2 * 4} no valid SXML

Smartsite SXML	Copy Code
{sys.eval(2 * 4)} valid SXML

Using the Sys.Eval Overloads with 'translationScope' and 'fallbackScope'

Normally, translation scope is resolved automatically when SXML is parsed. For normal translations, this will be the current item.

Sys.Eval() is no exception. If a translation is called anywhere within your Sys.Eval() call, the translation will be called using the current scope.

Sometimes, you may want to execute some code pretending that the current translation scope is different.

The two overloads with 'translationScope' and 'fallbackScope' can be used to do that.

Smartlets

The call syntax with 'translationScope' and 'fallbackScope' is especially handy for subclassing scenarios in Smartlets.

Region Example

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<se:region whitespace="remove"> {buffer.set(a, 1795)} <se:region> {buffer.set(a, 2)} {sys.eval(buffer.get(a) * 2)}/ </se:region> {buffer.get(a)} </se:region> {buffer.get(a, default=0)}

Sys.Eval() Example with custom Translation Scope

Smartsite SXML	Copy Code
{sys.eval(mytranslation(), HOME)}

More examples

• Smartlet Architecture
  Introducing the Smartlet Architecture.