THTTPsend
lazarus / 38-Networking and Web Programming

----------------------------------------------------------------------
DanishMale · 2025-08-01 11:33

Hi

I am a total newbie to Synapse and HTTPsend and don't seem to be able
to find the correct settings

I have written this code and it returns 500 - Internal server error

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
GetHTTP(webaddress: String; headerdata: TStringList = nil):
String;const  WEB_USERAGENT : Array of String = (  'Mozilla/5.0
(Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/138.0.0.0 Safari/537.36',  'Mozilla/5.0 (Windows NT 10.0;
Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0',  'Mozilla/5.0
(Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/138.0.0.0 Safari/537.36 Edg/138.0.0.0'  );begin  WEBdata :=
THTTPsend.Create;  try    WEBdata.Clear;    WEBdata.Protocol:='1.1'; 
 WEBdata.UserAgent := WEB_USERAGENT[RandomBetween(0,
Length(WEB_USERAGENT)-1)];    WEBdata.KeepAlive := True;   
WEBdata.MimeType := headerdata[0];    headerdata.Delete(0);   
WEBdata.Headers.AddStrings(headerdata);    if not
WEBdata.HTTPMethod('GET', webaddress) then    begin      raise
exception.create(IntToStr(WEBdata.ResultCode) + ' - ' +
GetHTTPerrorText(WEBdata.ResultCode));    end;    Result :=
WEBdata.Document.ReadAnsiString;  except    on E: Exception do   
begin      Result := 'ERROR -
'+E.Message+LineEnding+LineEnding+IntToStr(WEBdata.ResultCode) +     
         ' - ' + GetHTTPerrorText(WEBdata.ResultCode) +              
LineEnding+LineEnding+WEBdata.Headers.Text;    end;  end;  headerdata
:= nil;  WEBdata.Free;end; 
and is called with this code:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Button2Click(Sender: TObject);begin  Memo1.Clear;  HeaderList
:= TStringList.Create;  HeaderList.Clear;  HeaderList.Add('text/html,a
pplication/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'); 
HeaderList.Add('Accept: */*; q=0.01');  HeaderList.Add('Accept-
Language: da,en-US;q=0.7,en;q=0.3');  HeaderList.Add('Accept-Encoding:
gzip, deflate, br, zstd'); 
Memo1.Lines.Add(GetHTTP('https://www.tnt.fr', HeaderList));end; 
I have added laz_synapse to the project and upgraded to ssl_openssl3
in synapse also downloaded the latest DLL's in x64.

I wonder what I can't see or overlooking..........

Any help is really appreciated

----------------------------------------------------------------------
rvk · 2025-08-01 11:38

First line in your header string list is
Content-Type: text/html

You take that and put it in thhtpsend.mimetype.
The ENTIRE line.
That's incorrect. You need to only take the value after : and out it
in mimetype.

----------------------------------------------------------------------
DanishMale · 2025-08-01 11:45

Quote from: rvk on August 01, 2025, 01:38:52 pmFirst line in your
header string list is
Content-Type: text/html

You take that and put it in thhtpsend.mimetype.
The ENTIRE line.
That's incorrect. You need to only take the value after : and out it
in mimetype.

Corrected , however, still same error ....

----------------------------------------------------------------------
rvk · 2025-08-01 12:49

First I'm not entirely sure why you want to set a MimeType (Content-
Type) for a GET.

Second... you do get an error 500 when openssl isn't initialized
properly.
Did you add ssl_openssl or ssl_openssl3 to your uses clause?
And put the correct openssl dll's in the exe directory.

Third... I'm not sure you can use THTTPSend.Document.ReadAnsiString to
get the data.
It is a TMemoryStream so TStream.ReadAnsiString should work but for me
it crapped out with a read stream exception.
You CAN'T use TStream.ReadAnsiString because that expects a length at
the beginning of the stream (see the ReadBuffer (TheSize ) at the
beginning).

You can use this snippet to put the content of the memorystream to a
string;
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
MemoryStreamToString(M: TMemoryStream): ansistring;begin 
SetString(Result, PAnsiChar(M.Memory), M.Size);end;

----------------------------------------------------------------------
Thaddy · 2025-08-01 13:39

I would not use Synapse for that anymore, but TFPHttpClient: better
maintained, modern and standard.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {$mode
objfpc} uses  Sysutils, classes, fphttpclient, opensslsockets;  const 
WEB_USERAGENT : Array of String = (  'Mozilla/5.0 (Windows NT 10.0;
Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0
Safari/537.36',  'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0)
Gecko/20100101 Firefox/128.0',  'Mozilla/5.0 (Windows NT 10.0; Win64;
x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0
Safari/537.36 Edg/138.0.0.0'  );  var  Client: TFPHttpClient; 
Page:TStrings;begin  Client := TFPHttpClient.Create(nil);  Page :=
TStringlist.Create;  try    Randomize;    Client.AddHeader('User-
Agent', WEB_USERAGENT[Random(High(WEB_USERAGENT)+1)]);   
Client.AddHeader('Content-Type','text/html,application/xhtml+xml,appli
cation/xml;q=0.9,*/*;q=0.8');    Client.AddHeader('Accept-Encoding',
'gzip, deflate, br, zstd');    Client.AddHeader('Accept-Language','
da,en-US;q=0.7,en;q=0.3');    Client.AddHeader('Accept', '*/*;
q=0.01');    Client.AllowRedirect := true;    try     
Client.Get('https://www.tnt.fr',Page);      Writeln(Page.Text);     //
or simply writeln(Client.Get('https://www.tnt.fr',Page)) and save you
a stringlist    except      on E:Exception do       
writeln(e.message);    end;  finally    Page.Free;    Client.Free; 
end;end.