QueryFields
property QueryFields: TStrings read;
Example
procedure ScriptEvent(var Value: variant);
begin
if (Request <> nil) and (Request.QueryFields <> nil) then
Value := Request.QueryFields.Values['id']
else
Value := '';
end;
Usage
QueryFields returns a cached mutable list built by ampersand-splitting and then URL-decoding each complete query field as UTF-8.
Additional Technical Info
On first access, WebBroker creates a TStringList and parses Query. It separates fields at unquoted ampersands, URL-decodes each entire extracted field, converts + to space and interprets decoded bytes as UTF-8 under the active default settings. Each line is then typically Name=Value and can be read through TStrings.Values.
Decoding after field splitting has observable effects. %26 remains within one list item and becomes &; %3D becomes = before TStrings later identifies the name/value separator, so an encoded equals sign in a name can change how Values[...] sees that line. Duplicate names and input order are preserved as separate lines, while Values['name'] can hide later duplicates. Enumerate entries when duplicates are forbidden or significant.
The parser raises EConvertError for malformed percent encoding. Because the list is assigned before extraction starts, an exception can leave a partially populated cached list; a later QueryFields read returns that partial list without reparsing. Handle malformed input as a terminal client error rather than continuing with the cache.
The returned list is host-owned and mutable. Do not free it. Adding/changing/deleting lines affects later consumers of this request but does not rewrite the encoded Query or the HTTP request. It is not thread-safe.
Define an allow-list of parameter names, maximum counts/lengths, duplicate policy and type validation. Do not put credentials/secrets in query parameters. Test Request for nil.
External references
Created 2026-07-15