How to correctly declare an array property in Delphi? - arrays

Question

I'm trying to create an array to store every item of a TStringList into an array which size may vary depending on the quantity of items in said TStringList.
I know my syntax is wrong and what I want is probably a dynamic array, so the [0..100] is probably wrong aswell but I could not find any alternative syntax online.
ProductAvailabilityResult = Class(TRemotable)
private
FResultArray : array[1..100] of string;
published
property ResultArray[Index: Integer]: array of string read FResultArray write FResultArray;
End;
And this is how I would invoke it and populate it. conditionList being my TStringList which I would populate into my array.
for I := 0 to conditionList.Count - 1 do
begin
aProductAvailabilityResult.ResultArray[I] := conditionList[I];
end;
In case you may or may not have alternative suggestions to what i'm doing, the reason for this setup is because it's a web service app sending results over a SOAP server, and I don't think my PHP/Soap client can read TStringLists, so I need to pass it to an array first.
Let me know, Thanks!

Answer 1

Your syntax for declaring an array property is close, but you need to use getter/setter methods instead of direct field access, and array properties cannot be declared as published:
type
ProductAvailabilityResult = class(TRemotable)
private
FResultArray : array of string;
function GetResultArray(Index: Integer): string;
function GetResultArrayCount: Integer;
procedure SetResultArray(Index: Integer; const Value: string);
procedure SetResultArrayCount(Value: Integer);
public
property ResultArray[Index: Integer]: string read GetResultArray write SetResultArray default;
property ResultArrayCount: Integer read GetResultArrayCount write SetResultArrayCount;
end;
function ProductAvailabilityResult.GetResultArray(Index: Integer): string;
begin
Result := FResultArray[Index];
end;
function ProductAvailabilityResult.GetResultArrayCount: Integer;
begin
Result := Length(FResultArray);
end;
procedure ProductAvailabilityResult.SetResultArray(Index: Integer; const Value: string);
begin
FResultArray[Index] := Value;
end;
procedure ProductAvailabilityResult.SetResultArrayCount(Value: Integer);
begin
SetLength(FResultArray, Value);
end;
Then you can do this:
aProductAvailabilityResult.ResultArrayCount := conditionList.Count;
for I := 0 to conditionList.Count - 1 do
begin
aProductAvailabilityResult[I] := conditionList[I];
end;
You might want to consider adding a method to copy strings from a source TStrings:
type
ProductAvailabilityResult = class(TRemotable)
private
...
public
procedure AssignStrings(AStrings: TStrings);
...
end;
procedure ProductAvailabilityResult.AssignStrings(AStrings: TStrings);
var
I: Integer;
begin
SetLength(FResultArray, AStrings.Count);
for I := 0 to AStrings.Count - 1 do
FResultArray[I] := AStrings[I];
end;
aProductAvailabilityResult.AssignStrings(conditionList);

Answer 2

You've declared an array property, albeit with some syntax errors. However, you state in the question and comments that you want a property that is a dynamic array. That's different from an array property.
Declare a dynamic array property like so:
type
ProductAvailabilityResult = class(TRemotable)
private
FResultArray: TArray<string>;
published
property ResultArray: TArray<string> read FResultArray write FResultArray;
end;
Populate it like this:
var
i: Integer;
List: TStringList;
par: ProductAvailabilityResult;
arr: TArray<string>;
....
List := ...;
par := ...;
SetLength(arr, List.Count);
for i := 0 to List.Count-1 do
arr[i] := List[i];
par.ResultArray := arr;