[How to prevent simultaneously call a procedure/function ?]

Use critical sections for this.

 

Hello Farshad Mohajeri,

 

Thank you for your help.

 

It works with critical sections.

 

I have another question.

Is it possible to reject / terminate concurrent call a procedure/function,

in this case not using critical section.

I mean the second client call for the procedure/function will be informed that

the procedure/function is being called by other client.

 

Thanks

[How to prevent simultaneously call a procedure/function ?]

Hi All,

 

How to prevent a procedure/function been called simultaneously by 2 or more clients ?

 

I use a global variable as a flag.

code like this :

var
 isCalled: Boolean; // Global variable

function TMainForm.UpdateData: Boolean;
begin
 if isCalled then
   Exit(False); // exit cause this function is being called by other client

 isCalled:= True; 
 .
 <my code>
 <my code>
 .
 isCalled:= False; // set isCalled to False in order other client can call this function
 Exit(True);
end;

 

It works but I think this is not safe because there is still possibility this function been called

simultaneously if this function is called at the same time by two or more clients.

 

is there any other way ?

 

Thanks in advance.

Hendra

[Unigui call Datasnap function simultaneously]

In unigui applications, each user session can't share same vars/objects, becouse each user session have her own thread, then better way is create ojects/vars into unimainmodule.

 

Remove ClientModule1 from autocreate, declare public var on mainmodule class, and create it on mainmodule.oncreate

 

procedure TUniMainModule.UniGUIMainModuleCreate(Sender: TObject);
begin
 Client:=TClientModule1.Create(self);
end;

 

then, in mainform you must access UnimainModule.Client

 

Procedure TMainForm.UniBitBtn1Click(Sender: TObject);
var
 i,x: Integer;
begin
 UniListBox1.Clear;
 for I := 1 to 10 do begin
   x:= UniMainModule.Client.ServerMethods2Client.RetValue(i);
   UniListBox1.Items.Add(IntToStr(x));
 end;
end;

 

Hello Docjones,

 

I works, problem solved.

 

Thanks for your help.

[Unigui call Datasnap function simultaneously]

My application project :

uniGuiAndDataSnap.rar

[Unigui call Datasnap function simultaneously]

Hi all,

 

My unigui apps call a simple function in a Datasnap application simultaneously.

I am using Delphi XE.

 

the function in Datasnap is:

function TServerMethods2.RetValue(aVal:Integer): Integer;
begin
 Sleep(1000); // pause execution for simulating simultaneous execution
 Exit(aVal);
end;

the function just return back the parameter value, no other calculation.

 

and the code to call the RetValue function in uniGui application :

procedure TMainForm.UniBitBtn1Click(Sender: TObject);
var
 i,x: Integer;
begin
 UniListBox1.Clear;
 for I := 1 to 10 do begin
   x:= ClientModule1.ServerMethods2Client.RetValue(i);
   UniListBox1.Items.Add(IntToStr(x)); // Return value in listbox
 end;
end;

 

and the correct result is :

 

but if I call the DataSnap function simultaneously by opening the uniGui in two firefox tabs, it retuns variety

wrong value.

 

 

 

 

 

How can I solve the problem and thanks in advance.

 

Thanks

Hendra

[Access Variable in ClientEvent]

The easiest (but not the best) way is to create a hidden unilabel and store variable in its caption so you can access it in client browser.

The right way is to create your own "namespace" in javascript globals and store variables there with UniSession.AddJS(), something like this

 

window.MyVars = window.MyVars || {};
window.MyVars.Salary = 1000;

...

function OnClick(sender, e)
{
 if window.MyVars.Salary < 10000 then ...

 

Hi. Thanks for your help.

[Access Variable in ClientEvent]

Hi All,

 

Please help.

I am newbie in Web Application

 

I want the ClientEvent OnClick Execute ajaxRequest with EventName depend on an variable value declare in MainForm

 

For example :

 

Salary is variable declare in MainForm

 

function OnClick(sender, e)

{

if (Salary < 10000)

{

ajaxRequest(sender, 'Event1');

}

else

{

ajaxRequest(sender, 'Event2');

}

}

 

Please help me to correct the function above.

 

Thanks in advance.

[How to connect database reside other place than in web server]

Did you install on the 2.22.22.222 computer

the Firebird client.

Since you're using ADO did you install, configure and test the ODBC driver ?

 

Hi,

Firebird server run on 2.22.22.222 (Web server) and 3.33.33.333 (client computer)

Maybe Firebird server need not run on 2.22.22.222 (Web server) cause Database now on 3.33.33.333, I will test it later.

 

I use Anydac not ADO, not configure and test the ODBC driver.

[How to connect database reside other place than in web server]

Disable firewall solve the problem.

I have to disable Windows Firewall and firewall of anti virus Eset Smart Security on the client computer.

 

My uniGui Web Application can connect remote database.

[How to connect database reside other place than in web server]

Can you ping db server from web server?

Hi, thanks and sorry for my late reply.

 

Yes I can ping db Server(client computer) from web server and vice versa.

 

And the process connecting database is done in client computer, this mean

the user in client computer try to connect his local database.

 

I also try to remote connect the client database (I can ping the client computer) from my computer with Desktop application (create with VCL Delphi not uniGUI) but failed either.

 

the error message is :

 

Unable to complete network request to host 'xx.xx.xxxx' <- client ip address

failed to establish a connection.

 

 

I used to be able remote connect the client database use the desktop application but now fail to connect.

 

So I think this is not because of UniGUI application, but network connection problem.

 

I use Logmein Hamachi to connect client computer.

[How to connect database reside other place than in web server]

Hi All,

 

I am using AnyDac component and firebird database.

 

Suppose that the Web Server IP Address is 2.22.22.222 and the web application

want to connect database reside in client computer (IP Address 3.33.33.333)

 

with code like this :

 

idx:= ADConnection1.Params.IndexOfName('Database');

ADConnection1.Params[idx]:= 'Database= 3.33.33.333:C:\Employee.fdb';

ADConnection1.Connected:= True;

 

raise Ajax Error : Server unavailable

 

My plan is not to host the web application and the database in the same computer.

 

as I read article Database Security Best Practices :

 

Separate the Database and Web Servers

 

so that mean the web application computer and database server computer will have different IP Address.

 

Thanks in advance.

[How Save File To Client Storage]

You save local and like upload the file to web?

Then you must use UniFileUpload, for

Download use unisession.sendfile.

 

Hi,

Yes, it works

use unisession.sendstream no need save the file excel to server then download to client.

[How Save File To Client Storage]

please see demo sample for first

 

Hi Irwan, thanks for reminding me.

I already saw demo samples before but I forget there are these download demo samples.

 

 

Regards,

Hendra

[How Save File To Client Storage]

You save local and like upload the file to web?

Then you must use UniFileUpload, for

Download use unisession.sendfile.

 

Ok, I will try it in my client computer tomorrow

unisession.sendfile act like download file so client user may should open the file first

and then save it to the target directory.

 

 

Thanks.

[How Save File To Client Storage]

Hi,

 

no problem, use UniSession.SendFile Method for this.

 

We do the same, we create a Excel file with flexcelreport from TMS

and the Unisession.sendfile method.

 

Hi Gerhard Kimmeringer, Thank you for your help.

 

I am new in web application,

can you kindly help what the code in my case use UniSession.SendFile Method,

I am using NativeExcel.

Suppose the client user want to save the excel to directory C:\Reports

 

In desktop application the code is :

WorkBook.SaveAs('c:\Reports\Report.xls');

 

Regards,

Hendra

[How Save File To Client Storage]

Hi All,

 

My application need to convert data to Excel file and save the Excel file to client computer (harddisk/flash disk).

 

Can web Application save the Excel to Client Computer ?

 

with code :

 

WorkBook.SaveAs('c:\Report.xls');

 

the report.xls will be saved in web server harddisk not in the client harddisk.

 

 

Thanks in advance

[Edit Data unidbGrid (Desktop VS Web Mode)]

Hi All,

 

uniDBGrid has a different behavior in editting a cell value between desktop and web mode.

In desktop mode, in a selected cell we can just type a new value then the selected value will be overwrite,

but in web mode before typing we should type Enter key to unselect the cell value.

 

How can I change this behavior so in web mode dbgrid can be like in desktop mode ?

 

thank in advance

 

Sorry for my bad english.