How to return a local variable in an expression?

Question

So I have a local variable in an expression rule. Is there a way to set that value as the return value of the expression rule?

Mike Schmitt · Accepted Answer

Yes - just call the local variable again. 
 a!localVariables(
 local!test: "Hello World!",
 
 "Here is our local variable value: " & local!test
)

Mike Schmitt · Answer

Likewise, you will need to revise how you're setting local!currentDistance. One of the most straightforward ways to do it is to set it up-front just after your local!offices are declared: 
 local!officeDistances: a!forEach(
 items: local!offices,
 expression: rule!Geo_computeDistanceBetween(
 ri!Longitude, 
 ri!Latitude, 
 fv!item.Longitude,
 fv!item.Latitude
 )
) 
 This will create an array of distances with one item in each array for each item in the local!offices array.

Mike Schmitt · Answer

swolfe5555 said: What is the purpose of a local variable if I can't use it in this situation? 
 I don't believe it's accurate to say you can't use them - the issue isn't that you want to use them, but rather that you're trying to use them in a way that they aren't made for. They work differently than in traditional programming languages, so it's a good idea to get used to how they do (and don't) in order to accomplish advanced functionality. 
 The concept you're missing here is - instead of creating a local variable initialized with a temporary value, and trying to back-save a new value later (outside of a user-interactive component), you should set each local variable to hold its desired value initially. Then you can use that local variable either as you set subsequent local variables, or in your output.

Mike Schmitt · Answer

No prob - here's a streamlined version I created that demonstrates how this would probably work best for you (though you'll need to figure out a way to re-add the calculation for radiusThreshold at some point, but just for example: 
 /*
Define the local variables for the function
*/

a!localVariables(
 /*Will hold the table from the query that will be looped through*/
 local!offices: a!queryEntity(
 entity: cons!Geo_locationDBE,
 query: a!query(
 logicalexpression: a!queryLogicalExpression(
 operator: "AND",
 filters: {
 a!queryFilter(
 field: "Location_ID",
 operator: "not includes",
 value: "DUMMY"
 )

 }
 ),
 selection: a!querySelection(columns: {
 a!queryColumn(field: "Location_ID"),
 a!queryColumn(field: "Area_Name"),
 a!queryColumn(field: "Longitude"),
 a!queryColumn(field: "Latitude"),
 a!queryColumn(field: "Zipcode"),
 }),

 pagingInfo: a!pagingInfo(
 startIndex: 1,
 batchSize: -1 
 )
 )

 ),

 local!officeDistances: a!forEach(
 items: local!offices,
 expression: rule!Geo_computeDistanceBetween(
 ri!Longitude, 
 ri!Latitude, 
 fv!item.Longitude,
 fv!item.Latitude
 )
 ),
 
 local!closestDistance: min(local!officeDistances),
 
 /* find closest office (assumes no duplicate distances) */
 local!closestOffice: index(
 local!offices.data, /* edited */
 where(local!officeDistances = local!closestDistance)
 ),

 local!closestOffice

)

Mike Schmitt · Answer

Well, I see your issue - a!save() only works within the saveInto parameter of an interactive component upon input from a user, and does not work in an expression rule to dynamically set the value of a previously declared variable. What you should be doing instead is setting the value of local!outLocation to the logic needed to determine its value. That or just get rid of the local!outLocation variable and directly return the value of your a!forEach at the end. So basically you'll need to reformat the entire last block of your expression.

How to return a local variable in an expression?

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