TryCF Gist

trycf-gist-1543450180046-4f955023-8a58-06ae-6655-aa31370840c4.cfm

<cfscript>
    // Set up the query object to represent our rates.
	myQuery = queryNew(
		"code, rate",
		"integer, integer",
		[
		  { "code" : 1 , "rate" : 10 } , 
		  { "code" : 2 , "rate" : 15 } , 
		  { "code" : 3 , "rate" : 20 } , 
		  { "code" : 4 , "rate" : 25 } , 
		  { "code" : 5 , "rate" : 30 }
	    ]
	);
	
	//writeDump(myQuery) ;

function returnNewRates( required Numeric origCode, required Numeric toCode ) {
    local.ratesStruct = { "origRate":-1, "toRate":-1 } ;
    
    // This will be our query. If we _have_ to use an existing query, pass it in and duplicate() it. (Pass by Reference!)
    local.qry = duplicate( myQuery )  ; 
    /////////////
    // Closure to filter the query. This should be done in SQL.
    local.filteredQuery = qry
        .filter( function (obj) {
                return ( obj.code == origCode || obj.code == toCode ) ;
        } ) ;
    
    // Now assign new rates. NOTE: The query shouldn't return more than 2 rows. We can validate if needed.
    for ( var r IN filteredQuery ) {
        if( r.code == arguments.origCode ) { ratesStruct.origRate = r.rate ; }
        if( r.code == arguments.toCode ) { ratesStruct.toRate = r.rate ; }
    }
    
    return ratesStruct ;
}


//// TESTS ////
writedump( returnNewRates(1, 2) ) ; // Get 2 valid values.
writedump( returnNewRates(2, 9) ) ; // Get 1 invalid value. 
writedump( returnNewRates(3, 3) ) ; // Get same value for both.
writedump( returnNewRates(1, 2) ) ; // We didn't change the base query?

</cfscript>