Inno Setup: Change value in JSON array - json

Question

I would like to create an installer with the help of Inno Setup. In order to make the program work on every computer, I need to change the tool directory in a .json-file. Here is an excerpt from this file:
{
"commandScriptLinux" : "",
"copyToolBehavior" : "once",
"deleteWorkingDirectoriesAfterWorkflowExecution" : true,
"deleteWorkingDirectoriesKeepOnErrorOnce" : true,
"deleteWorkingDirectoriesNever" : true,
"documentationFilePath" : "",
"enableCommandScriptWindows" : true,
"imitationScript" : "",
"imitationToolOutputFilename" : "",
"launchSettings" :
[
{
"limitInstallationInstancesNumber" : "1",
"limitInstallationInstances" : "false",
"toolDirectory" : "%Selected Setup Folder%",
"version" : "1.0"
}
],
}
I hoped to solve this by using the inno-json-config library. Unfortunately, after executing the code, the lines are reversed (last line comes first now) and the changes weren't made.
[Setup]
AppName=Change_Config
AppVersion=1.0
DefaultDirName={userdocs}\Change_Config
[Files]
Source: "JSONConfig.dll"; Flags: dontcopy
[Code]
function JSONQueryString(FileName, Section, Key, Default: WideString;
var Value: WideString; var ValueLength: Integer): Boolean;
external 'JSONQueryString#files:jsonconfig.dll stdcall';
function JSONWriteString(FileName, Section, Key,
Value: WideString): Boolean;
external 'JSONWriteString#files:jsonconfig.dll stdcall';
procedure InitializeWizard;
var
FileName: WideString;
IntValue: Int64;
StrValue: WideString;
StrLength: Integer;
BoolValue: Boolean;
begin
FileName := 'c:\configuration.json';
SetLength(StrValue, 16);
StrLength := Length(StrValue);
if JSONQueryString(
FileName, 'launchSettings', 'toolDirectory', 'Default', StrValue, StrLength) then
MsgBox('Section_1:Key_1=' + StrValue, mbInformation, MB_OK);
if not JSONWriteString(FileName, 'launchSettings', 'toolDirectory', 'Test') then
MsgBox('JSONWriteString Section_1:Key_1 failed!', mbError, MB_OK);
end;
Thank you very much for your support!
Regards,
Alex

Answer 1

The launchSettings is an array. I believe that the inno-json-config library does not support arrays.
You can use JsonParser library instead.
[Code]
#include "JsonParser.pas"
function FindJsonValue(
Output: TJsonParserOutput; Parent: TJsonObject; Key: TJsonString;
var Value: TJsonValue): Boolean;
var
I: Integer;
begin
for I := 0 to Length(Parent) - 1 do
begin
if Parent[I].Key = Key then
begin
Value := Parent[I].Value;
Result := True;
Exit;
end;
end;
Result := False;
end;
function FindJsonArray(
Output: TJsonParserOutput; Parent: TJsonObject; Key: TJsonString;
var Arr: TJsonArray): Boolean;
var
JsonValue: TJsonValue;
begin
Result :=
FindJsonValue(Output, Parent, Key, JsonValue) and
(JsonValue.Kind = JVKArray);
if Result then
begin
Arr := Output.Arrays[JsonValue.Index];
end;
end;
{ ... }
var
JsonLines: TStringList;
JsonParser: TJsonParser;
LaunchSettingsArray: TJsonArray;
ToolDirectoryValue: TJsonValue;
I: Integer;
begin
{ ... }
JsonLines := TStringList.Create;
JsonLines.LoadFromFile(FileName);
ParseJson(JsonParser, JsonLines.Text);
if Length(JsonParser.Output.Errors) > 0 then
begin
Log('Error parsing JSON');
for I := 0 to Length(JsonParser.Output.Errors) - 1 do
begin
Log(JsonParser.Output.Errors[I]);
end;
end
else
begin
if FindJsonArray(
JsonParser.Output, JsonParser.Output.Objects[0],
'launchSettings', LaunchSettingsArray) and
(GetArrayLength(LaunchSettingsArray) >= 0) and
(LaunchSettingsArray[0].Kind = JVKObject) and
FindJsonValue(
JsonParser.Output,
JsonParser.Output.Objects[LaunchSettingsArray[0].Index], 'toolDirectory',
ToolDirectoryValue) and
(ToolDirectoryValue.Kind = JVKString) then
begin
Log(Format(
'launchSettings[0]:toolDirectory:%s', [
JsonParser.Output.Strings[ToolDirectoryValue.Index]]));
JsonParser.Output.Strings[ToolDirectoryValue.Index] := 'Test';
JsonLines.Clear;
PrintJsonParserOutput(JsonParser.Output, JsonLines);
JsonLines.SaveToFile(FileName);
end;
end;
ClearJsonParser(JsonParser);
JsonLines.Free;
end;
It still won't preserve the order (but that should not matter).
Though in your case, you do not need to parse the JSON. You can simply replace the %Selected Setup Folder% with the desired value.
See Replace placeholder in an installed text file with input entered by user.