Is there a case statement /function in Appian . or an if ...else if in rules exp

Question

Is there a case statement /function in Appian . or an if ...else if in rules expressions . Coding in terms of if , if ... is time consuming and code readability is bad .

chetany · Answer

I would suggest a combination of fn!choose and fn!displayvalue to simulate a "switch" case in Appian. fn!choose is like switch case - but with one caveat - the "key" should be a number - it does not allow text values or float values. So, you can use fn!displayvalue with fn!choose when the value which decides which branch to takes is not a number. Example Snippet: load( /*local!statusCode will be 1 or 2 or -1 1 - Approved 2 - Rejected -1 - Some invalid value*/ local!statusCode: fn!displayvalue( ri!status, {"Approved", "Rejected"}, {1,2}, -1 ), fn!choose( local!statusCode, { /*code for choice1 */ }, { /*code for choice2 */ } ) )

sikhivahans · Answer

As long as the rule doesn't return a list, an additional call to fn!choose() isn't required and requirement can be accomplished just by making use of fn!dislayvalue() as follows:

fn!displayvalue(
ri!status,
{
                    "Approved",
                    "Rejected"
          },
{
                    rule!myRuleForApprovedStatus(),
                    rule!myRuleForRejectedStatus()
          },
rule!myDefaultRule()
)

In case if the rules returns lists, fn!choose() can be used.

amitb0004 · Answer

Hi Dhiraj Kumar, 
There is one function "choose( index, choice1, choice2, … )", you can used it as switch case logic...

follow the following link for more details: 
docs.appian.com/.../fnc_logical_choose.html 
 
And for if_else 
 
"if(condition,statement1, statement2)" 
in above syntax if condition is true "statement1" will get executed else "statement2" 
 
In these way you can used if_else in Appian