Miva / MVT: Use s.null for Null Values

miva-mvt-use-s-null-for-null-values--00-README.md

Use s.null For Unused Return Values

MivaScript 5.36 added support for s.null. s.null will always be null. Assigning a value to s.null does not change the value of s.null and avoids keeping the result of a function or expression in memory.

You can assign variables to s.null when you do not need to use the return variable for anything. By assigning variables to s.null, it more clearly indicates that the variable will not be used (as opposed to l.result or l.success). Just be sure you do not pass s.null (or variables assign to s.null by reference) into MivaScript or mvt:do functions

Incorrect

<mvt:do file="g.Module_Library_DB" name="l.success" value="Product_Load_Code( 'test', l.product )" />	
<mvt:assign name="NULL" value="miva_array_insert(l.foo, 'Foobar', -1)" />	

Correct

<mvt:do file="g.Module_Library_DB" name="s.null" value="Product_Load_Code( 'test', l.product )" />	
<mvt:assign name="s.null" value="miva_array_insert(l.foo, 'Foobar', -1)" />	

miva-mvt-use-s-null-for-null-values--01-example.xml

mvt:eval s.null=<mvt:eval expr="s.null" />	
<br>	
mvt:assign s.null=1<mvt:assign name="s.null" value="1" />	
<br>	
mvt:eval s.null=<mvt:eval expr="s.null" />

miva-mvt-use-s-null-for-null-values--02-output.txt

mvt:eval s.null=	
mvt:assign s.null=1	
mvt:eval s.null=