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Variable

property Variable[aCode: string]: TvxVariable read; default;

Example​

procedure ScriptEvent(var Value: Variant);
var WorkVar: TvxVariable;
begin
  WorkVar := Locals.Variable['BatchReference'];
  Value := WorkVar.Value;
end;

Usage​

Returns the variable identified by Code, using a case-insensitive match. The first request loads the variable; later requests with the same code return the same value until it is removed or all variables are cleared.

Lookup sequence

  1. Locks the list.
  2. Scans cached items linearly and compares Code with AnsiCompareText.
  3. Returns the first hit without refreshing Value.
  4. On a miss, creates TvxVariable.Create(nil), sets its Code to the exact argument, invokes GetValue(aCode), assigns the returned Variant and caches it.
  5. Unlocks and returns the borrowed list-owned object.

Normal base-list creation yields Null. Settings queries the system database; AzureSecrets can perform OAuth/HTTP/JSON work. All initial acquisition is inside the list lock. Errors behave according to the item: caught failures may still result in a cached Null/zero item.

Additional Technical Info​

Variable is the read-only default property of TvxVariableList.

These forms are equivalent:

WorkVar := Locals.Variable['BatchReference'];
WorkVar := Locals['BatchReference'];

Quirks and concurrency

  • Blank/whitespace Codes are accepted and cached.
  • Cache lookup is case-insensitive and O(entry count); exact first-request case remains on the object.
  • A hit does not re-run GetValue. Null/failure and successful source snapshots persist until invalidation/owner cleanup.
  • The returned object is never owned by the script. The list unlocks before its use; RemoveVariable, FreeAllVariables or owner destruction can invalidate it concurrently.
  • A variable setter can change Code after insertion, disrupting later lookup and creating duplicates; the list does not re-key entries.

For repeated access within a controlled execution, holding the borrowed variable can avoid linear lookup, but never retain it across owner cleanup or cache-management calls.

Created 2026-07-15