chkaufmann

It depends on what you plan to do. TatukGIS DK is a very good GIS library. We use it since 20 years. It offers a great map viewer component and the enterprise edition covers all common spatial formats. It's not expensive compared to ESRI products, but it's not cheap either.

If you just have some spatial data in a PostgreSQL/PostGIS database you can build your own SQL statements quite easy. Geometries are represented as WKT which is quite straight forward to understand. But of course it means programming work on your side.

Regards

Christian

I have an old project where I use TClientDataSet (unit DBClient.pas). When I recompile this one with Delphi 10.4.2 I get the following hint:

Hint: H2161 Warning: Duplicate resource:  Type 16 (VERSIONINFO), ID 1; File Pyramid.res resource kept; file C:\Program Files (x86)\Embarcadero\Studio\21.0\lib\Win32\release\DE\midas.res resource discarded.

Is this a (new) problem in my code or is this an error in the Delphi library code?

Regards

Christian

And I can confirm, that this fix works fine for me.

I just started to work with 10.4.2 (10.3. before) and have the same problem.

I changed my code and the error seems to be gone. Thanks a lot.

Now my last question is: Are there other potential problems I may have with my application when running in an RDP session? Especially other problems when loading / saving files from local drives? Until now I didn't find a good resource in the internet about where I should be carefull in my application in order to make it run without errors in RDP sessions:

Regards
Christian

2 hours ago, Kas Ob. said:

This means some files had been deleted and the overall archive file size need to be truncated, is it possible to write new file instead updating the existing one ? or just need to use overlapped operation and give the RDP protocol time to finish the file size updating.

I think I can change the code and create the .ZIP as temporary file and then copy/move this file to the local file on \\tsclient\..... 

- Normally I use CopyFile() or MoveFile(). What works better with the RDP protocol?

- When I look at Windows.pas unit there are many variants of these functions. Should I use a different one?

Thanks for your help.

Regards
Christian

When my application runs in an RDP session I get the following error:

exception class          : EOSError
exception message        : System Error. Code: 8. Not enough memory resources are available to process this command.

00469607 Logo12.exe   System.SysUtils                 RaiseLastOSError
004696d7 Logo12.exe   System.SysUtils                 Win32Check
00547faa Logo12.exe   System.Classes                  THandleStream.SetSize
005461af Logo12.exe   System.Classes                  TStream.SetSize64
010931ff Logo12.exe   ZipForge                   7047 TZFBaseArchiver.ForceUpdate
0109a2ea Logo12.exe   ZipForge                   9754 TZFBaseArchiver.EndUpdate
0109cd7e Logo12.exe   ZipForge                  10780 TZFBaseArchiver.DeleteFiles
0125d084 Logo12.exe   BSStreams                   939 TBSZipStreamWriter.Close

The problem is, the error doesn't happen on all clients, it even happens on some clients one day and the other day it's not reproducable. What I know is, it happens when the application creates and writes to a local file during a backup and it happens when the function SetEndOfFile(FHandle) is called. The error only apears when I try to save to a local file (located on any \\tsclient\.... path).

When I search the internet I don't find anything helpfull except about changing the settings for the Windows pagefile. Unfortunately the provider of our RDP plattform / servers cannot reproduce the problem. So I'm stuck somehow, I don't even understand if the error message points to the real problem. And I don't understand if this is a problem of resources on the local client or on the server where the RDP session is hosted.

Something else I know is, that some customers get the same error message when they launch the File Explorer in an RDP session and try to copy a big file from their local drive to the server. Therefor I think the problem cannot be in my application itself, it has to do something with the OS configuration on the server or on the client.

So any hint to isolate and fix the problem is welcome.

Thanks.

Christian

Hi,

my provider uses https://rspamd.com/ to check emails before sending out. Now my emails get classified by some modules and I would like to solve this:

One is https://rspamd.com/doc/modules/chartable.html

Normally I just add text with FMessage.Body.Add() and then I set this:

FMessage.ContentType := 'text/plain';
FMessage.CharSet := 'UTF-8';
 

Is Indy not doing the conversion correctly?

The second one is https://www.rspamd.com/doc/modules/mime_types.html this one. The others don't give a big score:

R_MIXED_CHARSET        2.89     Mixed characters in a message
MISSING_MIME_VERSION   2.00     MIME-Version header is missing in MIME message
R_BAD_CTE_7BIT         1.05     Detects bad content-transfer-encoding for text parts 7bit;utf8;
 

Can somebody give me a hint on how to fix this?

Christian

I use the full sql string as key now. Maybe I'm just too old - sometimes still thinking that having several thousand strings as keys may affect performance...

Christian

I use a cache for sql query results. For this I create a key with THashBobJenkins for the sql string and then I have dictionary with the results with these hashes as key.

Unfortunately I run into a problem that two different sql strings give the same hashkey. So I probably have to use the whole sql string as key. Or can somebody provide me a good solution to reduce the sql string to a "smaller" key without loosing uniqueness?

Christian

When I use TStringList.SaveToFile() on a hidden text file, I get a create error. Even if I do this as administrator.

So the only solution I see is to read the attributes with GetFileAttributes, then save the file and then use SetFileAttributes to hide the file again. Or do I miss something?

Christian

When a user starts my application, I would like to know all groups assigned to that user. On the command line I can do this:

dsquery user -samid "christian.kaufmann" | dsget user -memberof -expand

Now I have a delphi function I could use to run this call and then parse the input. But before I start to implement that I would like to know:

- Is a regular user allowed to call this in order to read that information?

- Is there another way to get this info from the system?

- Or are only administrators allowed to read this information?

The background is, I would like to show the user a list of available projects based on the groups he is a member of.

Christian

My problem is, that user managment is done by an external company with quite expensive people. Not my choice, and I just try to make things user friendly with the part I do.

One final question: The shared drives as UNC path look like \\tsclient\c\..... Is this "\\tsclient" a default by Microsoft in a terminal session or can this prefix be customized by the administrator?

Christian

Yes I know. In the end it's more to help the user do use only his local drives to save/load files.

Christian

My application runs on a server as remote desktop application. Now I want a function to add files from a local the drive. The RDP file is configured to map local drives and I can see/select these in the file open dialog.
Now I would like to limit this dialog to the clients local drives only. 
- Is there a global option for that?
- Is it enough to set a OnFolderChanging event and check the path to be a local drive?
- Are there other things todo? Since the file open dialog is almost a complete Explorer today, I would like to limit functionality to open/load a file.

Regards
Christian

Thanks for the reply. I have one final question. First I tried with this call:

var
  tmp : TIdBytes;

  FClient.IOHandler.ReadBytes(tmp, -1, False);
  FPartMsg := FPartMsg + IndyTextEncoding_UTF8.GetString(tmp);
  ....

Here I noticed, that if ReadBytes had nothing to read, tmp was not reset to length zero, but once some bytes could be read, tmp was set to the number of bytes. What is the reason for that?

Christian
 

My application has to connect to another application. It waits for messages in XML format, delimited with SOH and EOT. I wrote a listener thread. So far it works, but I wonder, if this is the way to do it. Here is my code:

- Is it correct to call ReadLn and then the thread is blocked until any data is sent by the server?

- I cannot test the error handling with SendData because I don't succeed to deactivate the server in the moment when the data is sent. Will it work that way? Or should I check another property of my TIdTcpClient to see if the server was deactivated?
- Do I need more cleanup if I destroy my TTsClient object?

Christian
 

type
  TTsClientThread = class(TThread)
  strict private
    FClient   : TIdTCPClientCustom;
    FMessages : IBSQueue<IBSXmlElement>;
    FPartMsg  : String;
  strict protected
    procedure Execute; override;
  public
    constructor Create(AClient: TIdTCPClientCustom; const AMessages: IBSQueue<IBSXmlElement>);
  end;

  TTsClient = class(TIdTCPClientCustom)
  strict private
    FListener : TTsClientThread;
    FMessages : IBSQueue<IBSXmlElement>;
  public
    constructor Create(const AIpAddress: String; APort: Integer);
    destructor Destroy; override;
    function IsAlive: Boolean;
    function Pop(var AMessage: IBSXmlElement): Boolean;
    procedure SendData(const AMessage: IBSXmlElement);
  end;

{ TTsClientThread }

constructor TTsClientThread.Create(AClient: TIdTCPClientCustom; const AMessages: IBSQueue<IBSXmlElement>);
begin
  FClient   := AClient;
  FMessages := AMessages;
  inherited Create;
end;

procedure TTsClientThread.Execute;
var
  s : String;
begin
  while not Terminated do begin
    try
      s := FClient.Socket.ReadLn(Char.EOT, IndyTextEncoding_UTF8).Substring(1);
      if not s.IsEmpty
        then FMessages.Append(NewBSXmlFromString(s));
    except
      on E: EIdSocketError do begin
        Terminate;
        Exit;
      end;
    end;
  end;
end;

{ TTsClient }

constructor TTsClient.Create(const AIpAddress: String; APort: Integer);
begin
  inherited Create(nil);
  FMessages   := TBSGenerics.GenQueue<IBSXmlElement>;
  Host        := AIpAddress;
  Port        := APort;
  Connect;
  FListener := TTsClientThread.Create(Self, FMessages);
end;

destructor TTsClient.Destroy;
begin
  FListener.Free;
  inherited;
end;

function TTsClient.IsAlive: Boolean;
begin
  Result := not FListener.Terminated;
end;

function TTsClient.Pop(var AMessage: IBSXmlElement): Boolean;
begin
  Result := FMessages.Pop(AMessage);
end;

procedure TTsClient.SendData(const AMessage: IBSXmlElement);
begin
  try
    Socket.Write(IndyTextEncoding_UTF8.GetBytes(Char.SOH + AMessage.AsXmlDataString([]) + Char.EOT));
  except
    on E: EIdSocketError
      do FListener.Terminate;
  end;
end;

For many enumeration type I have I define the same set of methods. Here is an example:

  TBSSwGender = (sgeNone, sgeMen, sgeWomen, sgeMixed);

  TBSSwGenderHelper = record helper for TBSSwGender
  public
    function AsInteger: Integer;
    function Code: String;
    function Name: String;
  end;

function TBSSwGenderHelper.AsInteger: Integer;
begin
  Result := Ord(Self);
end;

function TBSSwGenderHelper.Code: String;
begin
  Result := '#Enumeration.BSSwGenderCode%d'.Fmt([AsInteger]).Translate;
end;

function TBSSwGenderHelper.Name: String;
begin
  Result := '#Enumeration.BSSwGenderName%d'.Fmt([AsInteger]).Translate;
end;

Now my question is, instead of writing the same code for all types. So something like this:

TBSEnumHelper<T> = record helper for T
  function AsInteger: Integer;
  ...
end;

TBSEnumHelper<TBSSwGender> = record helper for TBSSwGender

Christian

This is what I did. The builder class itself has no RTTI. But I created a generic record.

IBSLookupElements is a simple collection of (Key, Caption, ParentKey) elements. Fmt() and Translate() are string helper methods for Format and language specific translations.
Then TBSCatalogBuilderSimple is a general subclass of my TBSCatalogBuilder class.

Here is my record definition:

type
  TBSCatalogBuilder<T> = record
  strict private
    FCatalogId : Integer;
    FDefault   : Integer;
    FName      : String;
    FTextIdent : String;
    FTypeData  : PTypeData;
  public
    constructor Create(ACatalogId: Integer; const AName: String);
    function Gen: TBSCatalogBuilder;
    function SetDefault(const AValue: T): TBSCatalogBuilder<T>;
    function SetTextIdent(const AValue: String): TBSCatalogBuilder<T>;
  end;

{ TBSCatalogBuilder<T> }

constructor TBSCatalogBuilder<T>.Create(ACatalogId: Integer; const AName: String);
var
  i : PTypeInfo;
begin
  i := TypeInfo(T);
  Assert(i.Kind = tkEnumeration, 'Passed type is not an enumeration.');
  FTypeData  := GetTypeData(i);
  FCatalogId := ACatalogId;
  FDefault   := 0;
  FName      := AName;
end;

function TBSCatalogBuilder<T>.Gen: TBSCatalogBuilder;
var
  tmp : IBSLookupElements;
begin
  tmp := NewBSLookupElements;
  for var ix := (FTypeData.MinValue + 1) to FTypeData.MaxValue
    do tmp.AddOrSet(FTextIdent.Fmt([ix]).Translate, ix);
  Result := TBSCatalogBuilderSimple.Create(FCatalogId, FName, tmp, FDefault);
end;

function TBSCatalogBuilder<T>.SetDefault(const AValue: T): TBSCatalogBuilder<T>;
begin
  FDefault := TValue.From<T>(AValue).AsOrdinal;
  Result   := Self;
end;

function TBSCatalogBuilder<T>.SetTextIdent(const AValue: String): TBSCatalogBuilder<T>;
begin
  FTextIdent := AValue + '%d';
  Result     := Self;
end;

Then the usage of the helper looks like this:

type
  TElmeSchlafmodus = (esmNone, esmKeinSchlafmodus, esmTeilzeit, esmVollzeit);

  ADef.RegisterCatalog(TBSCatalogBuilder<TElmeSchlafmodus>.Create(CAT_ELME_BETRIEB_SCHLAFMODUS, 'Schlafmodus')
                         .SetTextIdent('#ElmeBetrieb.Schlafmodus')
                         .SetDefault(esmVollzeit).Gen);

Thanks for all help.

Christian

Ok, here is the long story. In my system I define catalogs that can be used as lookup for values. There are complex catalogs with dynamic content that can be edited by the users. And there are simple catalogs that are hard coded in my application. For these hard coded catalogs I have builder class:

  TBSCatalogBuilder = class abstract
  strict protected
    function AddItem(AItemId: Integer; const AName: String; AIsDefault: Boolean = False; const AParentItem: IBSCatalogItem = nil): IBSCatalogItem;
    procedure DoBuildItems; virtual; abstract;
  public
    constructor Create(ACatalogId: Integer; const AName: String; AOptions: TBSCatalogOptions = []);
  end;

So to define a catalog I create a subclass of TBSCatalogBuilder, overwrite the DoBuildItems method and call AddItem several times to define the catalog.

Now some hard coded catalogs just represent the items of an enumaration type and instead of creating a subclass I would like one class with a constructor that takes the type of the enumeration and a second parameter with the default value. Right now the definition looks like this:

  TBSCatalogBuilderSetType = class sealed(TBSCatalogBuilder)
  strict protected
    procedure DoBuildItems; override; final;
  public
    constructor Create(ACatalogId: Integer; const AName: String; ASetType: PTypeInfo; ADefault: Integer = 0);
  end;

and then I can use it like this:

type
  TBSColumnType = (ctUnknown, ctBoolean, ctBytes, ctDateTime, ctFloat, ctInteger, ctMemo, ctString, ctGuid);

begin
  myColumnTypeCatalog = TBSCatalogBuilderSetType.Create(1, 'Column Types', TypeInfo(TBSColumnType), Ord(ctString));
end;

This works and it does what I want, but the TypeInfo() and the Ord() just don't look nice and I was wondering if there is not a way to avoid these. And I didn't want to define a generic class because like this the code is duplicated for every catalog. But maybe this is the only way to do it:

  TBSCatalogBuilderSet<T> = class(TBSCatalogBuilder)
  public
    constructor Create(ACatalogId: Integer; const AName: String; ADefault: T);
  end;

Christian
 

It's just a question of readability. My version works fine, but now I would like to avoid these TypeInfo() and Ord() when I call Foo().

And if I can validate the second parameter to be a valid member of the first (tkEnumeration) Parameter, this would be a nice additional check.

Christian

Yes "generic" is maybe the wrong word because I don't mean a generic method. Maybe I should have said untyped or typeless. I would just like to call it like this:

Foo(TSet1, a13);
Foo(TSet2, a21);

Christian

I have a generic method that requires an enumeration type and a value in this enumeration. Right now my function definition looks like this:

procedure Foo(ASetType: PTypeInfo; ADefault: Integer);

This works fine. With GetTypeData() I can extract what I need (number of elements in enumeration). However, in the usage of this function I have to add TypeInfo() and Ord() each time:

type
  TSet1 = (a11, a12, a13);
  TSet2 = (a21, a22, a23)

then I can call:

  Foo(TypeInfo(TSet1), Ord(a12));
  Foo(TypeInfo(TSet2, Ord(a23));

My question is, how to define the two parameters in order to avoid the TypeInfo() and the Ord() each time?

Christian

I have two applications that communicate in a LAN using UDP. Both applications have TIdUDPClient and a TIdUDPServer. Until now the user must configure the port and the IP address. Now I would like a solution where client computers "find each other" automatically. What is the best way to do that?

Regards
Christian

In my Windows applications I use VirtualTreeview for grids with inplace editors. Sometimes I load up to several 10'000 rows (nodes). For this I use rather light node classes.

When I look at TTreeviewItem in FMX, then each node is a control and I don't think, this will work the same way.

So are there alternatives. I need

- tree check functionality (simple, tristate)

- multiple columns

- inplace editors

- lazy load for child nodes

Christian