Hi all,

What about FastCGI, is there an implementation default in FPC?

I want codify a web app and I think use FreePascal. You recommend that? Or is better use another language like Java or Python? I prefer Pascal, but exists good Libs for that?

Thanks,
Marcos Douglas

Marcos Douglas wrote

What about FastCGI, is there an implementation default in FPC?

I haven't used FastCGI yet, but there seems to be an implementation included with FPC.

<fpc_src>/packages/fastcgi/*

I want codify a web app and I think use FreePascal. You recommend that?

Free Pascal is a very good choice for CGI web applications. You have the full RTL and FCL at your disposal. I even use a OPF (Object Persistent Framework) with our CGI apps.

Best of all, I didn't have to learn a new language like PHP, Java, Python etc. :-)

Hi Graeme,

I wanted know if many people here use that implementation of FastCGI.

Free Pascal is a very good choice for CGI web applications. You have the full RTL and FCL at your disposal. I even use a OPF (Object Persistent Framework) with our CGI apps.

YES, for me too. But I need to convence my team about that. For Web app, now, we use PHP.
I need to rewrite a Desktop app, coded in Delphi 7, to Web. The options: PHP, Java, C# and Pascal. For me, FreePascal would be a good choice, but the market here in Brazil does not like to use Delphi/Pascal any more... now, the most use Java or C#. So, because that, my team is worried about it, if exists support for reports, if is fast, etc.

Exists a project open source, in Pascal, here in Brazil. It's call ExtPascal <http://code.google.com/p/extpascal/>. This is a project to code Web apps. It use ExtJS for client and Pascal for server.

Best of all, I didn't have to learn a new language like PHP, Java, Python etc. :-)

Me too!

Marcos Douglas

Marcos Douglas wrote

I need to rewrite a Desktop app, coded in Delphi 7, to Web. The options: PHP, Java, C# and Pascal. For me, FreePascal would be a good

Some reasons:
* Free Pascal is open source (always available and no vendor lock-in)
* Free Pascal is free, so can always use latest version at NO cost.
* Previous skills from Delphi 7 project can be reused. No need to retrain developers. Saving 1000's in cost.
* Previous business domain code can be reused. Saving hundreds of hours in development time.
* No runtime or VM is required to run apps (unlike PHP, C# or Java).
* Development tools are free and again open source.

Exists a project open source, in Pascal, here in Brazil. It's call ExtPascal <http://code.google.com/p/extpascal/>. This is a project to code Web apps. It use ExtJS for client and Pascal for server.

I know of many developers or companies using ExtPascal to write web apps. I unfortunately have not looked at it yet. I started our CGI apps long before I found out about ExtPascal.

Here is a Web Server programmed entirely in Freepascal: http://ip.klimaregelung.de/ip.php?action=connect&benutzercode=Stratmann No Apache or PHP or something else.

Because it is a small embedded computer at home only 20 connections at a time are possible. But it would be possible to expand with more powerful computers.

I am HAPPY with Freepascal!

* Virtual Private Hosting is really cheap now, largely alleviating the problem of deploying native executables to web servers like FastCGI, ISAPI, apache_mod, etc.

I am working on a project now for RIA similar in concept to ExtPascal, but abstracting out the UI framework with most of the logic executing on the server so that I can plug in different UI's without touching my model/controller.

I was about 90% finished with the Flex UI layer when the customer whose site I'm writing, got spooked by all the Apple/Adobe/HTML5 debate that has heated up and became adamant about not using flash based UI, limiting Flash to playing video where necesary and using DHMTL for client UI.

So I'm taking advantage of the extra time and refactoring the framework a bit and implementing a DHTML UI layer now. We looked at ExtJS as well as YahooUI, OpenLaszlo and a few of the others and eventually decided on Dojo javascript tookit, but different UI layers can be plugged in. Heck, even an LCL or fpGUI layer is feasible.

how do I build a minimal 'hello world' CGI application under Free Pascal ?

Where do I find 'instructions for dummies' ?

Peppe

2010/5/2 Lee Jenkins :

how do I build a minimal 'hello world' CGI application under Free Pascal ? Where do I find 'instructions for dummies' ?

Have a look http://wiki.lazarus.freepascal.org/CGI_Web_Programming here .

Lele,

I need instructions for _dumbier_ users :)

1.
==

After hosted, CGI can now be used normally as http://www.yourserver.com[.xx]/yourlogin/cgi-bin/cginame.exe

(I will use my web browser, I suppose...)

However I have no web site on my server... :(

So where to store and how to call the application ?

2.
==

what should I see on screen ?

Thank you

Peppe

2010/5/3 leledumbo :

duilio foschi het geskryf:

how do I build a minimal 'hello world' CGI application under Free Pascal ?

Can't get simpler than this:

---------------------
program cgitest;
{$mode objfpc}{$H+}
uses
  Classes;
begin
  writeln('Content-Type:text/html',#10#13);
  writeln('<html>');
  writeln('<head><title>FPC Test</title></head>');
  writeln('<body>Hello World</body>');
  writeln('</html>');
end.

-----------------------

Output is shown in the attached screenshot. Obviously you need a webserver to correctly view the results. Simply install Apache and enable CGI support (if not enabled by default).

As you can see from the sample application, CGI apps are simply glorified console applications.

Regards,
- Graeme -

Yes, are good reasons.

I know of many developers or companies using ExtPascal to write web apps. I unfortunately have not looked at it yet. I started our CGI apps long before I found out about ExtPascal.

I do not knew about this! Can you post a few links of companies using ExtPascal? Would be very good to post these links in list of ExtPascal.

Well, ExtPascal use FastCGI approach. People say FastCGI is more powerful than CGI, because the application continues in memory... What about do you think about performance of CGI apps?

Do you use FastCGI or CGI?
How do you limits max connections?

I don't know what CGI is. Nevertheless I was able to program a webserver completely in freepascal. It isn't that complicate (if you have time). If a connection comes in then I prove how many connections are already open, and if it exceeds the max_connection value (which I set to 20 now) then I close immediately the new incoming connection. If you want I show you sample code. I work with nonblocked sockets. So everything is in one thread. best regards, Rainer

Marcos Douglas het geskryf:

I do not knew about this! Can you post a few links of companies using ExtPascal? Would be very good to post these links in list of ExtPascal.

Many are developers I read about in the Lazarus and FPC-users mailing list.

What about do you think about performance of CGI apps?

At the moment we use plain CGI apps. Even though our application needs to create on every user interaction a new database connection, our application is still sufficiently fast. Only after two years of development, did I find out about FastCGI and how it differs. So as soon as time permits, I will be porting our CGI apps to FastCGI - simply to keep database connections open, and keep other lookup lists in memory - this should improve performance a lot.

Regards,
- Graeme -

Hi Lee,

Lee Jenkins wrote

* Virtual Private Hosting is really cheap now, largely alleviating the problem of deploying native executables to web servers like FastCGI, ISAPI, apache_mod, etc.

Yes, you right.

I am working on a project now for RIA similar in concept to ExtPascal, but abstracting out the UI framework with most of the logic executing on the server so that I can plug in different UI's without touching my model/controller.

That is what I looking for!
That is what I looking for!
I do not want to use ExtPascal because it depends on ExtJS and their documents (to generate the Pascal code). I wish I could choose the JavaScript framework.

Your project is open source?
I'm very interested about that. Do you use some "template engine" for UI? The tecnology WebBroker (old Delphi) had macros for replace in events like #name or #salary. That is very simply but very coupled. We had HTML code coupled with Pascal code. The designers could not easily change UI code because that.

I will appreciate it very much see this code, thanks!

Rainer Stratmann wrote

I don't know what CGI is.

Here http://wiki.lazarus.freepascal.org/CGI_Web_Programming

What do you use in UI?
What about templates, do you use?

If you have some news about on learning FastCGI, tell us, please.

Graeme Geldenhuys wrote

At the moment we use plain CGI apps.

I forgot:

Do you continues using cgiapp unit?
Have you seen Powtils? Here
http://wiki.lazarus.freepascal.org/CGI_Web_Programming recommends.

Marcos Douglas het geskryf:

What do you use in UI? What about templates, do you use?

No templates and hard-crafted UI with our own HTML and CSS markup. Our CGI apps have a very dynamic interface which is build from information stored in a database.

If you have some news about on learning FastCGI, tell us, please.

I only know about FastCGI. I have never really looked at how it works yet. We do use PWU (Powutils), but actually just one or two methods, not much really. We can actually remove the dependency on PWU.

The version of PWU that we use are available for download in the following URL. The latest version in the PWU repository doesn't compile for us, for some months now. The project seems dead.

http://opensoft.homeip.net/~graemeg/pwu-1.6.0.2.tar.gz

Regards,
- Graeme -

Graeme Geldenhuys wrote

No templates and hard-crafted UI with our own HTML and CSS markup. Our CGI apps have a very dynamic interface which is build from information stored in a database.

There are HTML code inside Pascal code?

Thanks for the file.
So, you don't have any lib dependencies in your aplications?

Yes, I had plans to release it open source when its ready for testing, probably within 3-4 weeks from now.

The idea of the framework is mainly based on Proxy pattern. You build your gui within the server session, similar to how ExtPascal does it though with a more VCL/LCL kinds of model than ExtPascal. however, note that it doesn't use VCL/LCL and is based non-gui objects like TInterfacedPersistent to avoid dependencies on Lazarus LCL or Delphi VCL.

My goals in its development has been to ensure that the framwork overall:

A) Not tied to any particular GUI front-end, they should be swappable. I should be able to present my Model/Controller (or other business logic) in different UI's such as Flex, Silverlight, ExtJS, Dojo, OpenLaszlo, etc while still keeping 95% of the code on the server.

B) Any server platform or protocol. For instance, you should be able to deploy your application using what ever server protocol that is appropriate for the job. So feasibly you should be able to deploy your server app to FastCGI, Apache Module, ISAPI or even a stand alone synapse based HTTP server like I am using for testing.

Think of it as using the client UI as a puppet, with the server telling the client what to display through a two-way event system.

Here is a short screencast of the framework using the Flex UI layer. Note that its pretty old and the framework has come a long way since this screencast and as I said, I'm going through some refactoring now since I have to change some things for the customer anyway.

http://preview.tinyurl.com/18r

Not sure why TinyURL spazzed out with the first link but here is on that works:

http://preview.tinyurl.com/23uewfx

Marcos Douglas het geskryf:

There are HTML code inside Pascal code?

All HTML code (inside our pascal code) is tagged with class of div id's. We then use CSS to adjust our UI the way we want.

For inspiration of this concept, have a look at:
http://www.csszengarden.com/

All the pages (themes) available is all build with the exact same HTML file (nobody is allowed to change that file), just the CSS files are different. Pretty awesome!

Thanks for the file. So, you don't have any lib dependencies in your aplications?

Our CGI applications (three of them) are just one part of our complete product. We have a desktop GUI part as well. The CGI applications reuse a lot of code from the desktop. We implement the Model-GUI-Mediator design pattern, to split UI code from Business Domain code. Our applications talk to a Firebird RDBMS, and use SqlDB components, but we do *not* code for SqlDB directly. Instead we use tiOPF (http://www.tiopf.com) which is a Object Persistence Framework to manage all our data persistence (loading and saving of Objects). So with a single compiler define we can switch from Firebird to MySQL or PostgreSQL etc without a single line of code that needs to change. We can even switch database components (eg: SqlDB -> FBLib) with a single compiler define, and again, no lines of code need to change.

Regards,
- Graeme -

I am most interested to hear how tiOPF handles under a threaded environment when you move to FastCGI, Graeme.

Lee Jenkins wrote

Yes, I had plans to release it open source when its ready for testing, probably within 3-4 weeks from now.

This is great!

Interesting!

His framework already supports all of these UI?!

This is very interesting ... but you are not creating too many options? If there are many options, more harder it is to understand, isn't?

Thanks for the link!

Interesting... OK, thanks to sharing this idea.

Right. I also use an OPF made-in-home, but this is out of scope CGI's problems. BTW, is tiOPF life?

Lee Jenkins wrote

I am most interested to hear how tiOPF handles under a threaded environment when you move to FastCGI, Graeme.

Me too.

No. Only a partially finished Flex UI and the Dojo UI I'm working on now. My point was that would be possible to "plug in" different UI's.

I don't think so because the framework itself doesn't incorporate any communication protocols. Using your favorite existing Server platform (like fpWeb/LazWeb) you write a small method for when a request comes in like the one below to handle the request/response:

var
   lApp: TRiaApplication;
begin
   lApp := FServer.ServerPool.RetrieveOrCreateApplication(URI, lSessionOID);
   try
     lApp.HandleClientRequest(InputData, OutputData, Cookies);
     // Pass back and new or changed cookies to the server.
     if lApp.OutCookies.Count > 0 then
       begin
         for lCounter := 0 to lApp.OutCookies.Count - 1 do
           begin
             OutCookies.Add(lApp.OutCookies[lCounter]);
           end;
       end;
   finally
     FServer.ServerPool.ReleaseApplication(lApp);
   end;
end;

InputDate is the post data received from the client and OutputData is a stream that will contain the response to send to the client. So in your server application, you're just feeding the TRiaApplication with simple data to handle the request and sending back to the client the data that TRiaApplication provides back in the OutputData stream. Its always works the same way, since TRiaApplication doesn't care where InputData and OutputData come from so you can use any server platform and then simply feed the TRiaApplication as indicated.

The TRiaApplication.HandleClientRequest method has two overloads that can take either Streams or Strings:

procedure   HandleClientRequest(const AInput: string; var AReturnString: string;
ACookies: TStringList); overload; virtual;
     procedure   HandleClientRequest(AInStream, AOutStream: TStream; ACookies:
TStringList); overload; virtual;

Lee Jenkins wrote

I am most interested to hear how tiOPF handles under a threaded environment when you move to FastCGI, Graeme.

Well, Peter H. and others have used tiOPF in a threaded environment for years, so it does work. The only threaded part of tiOPF that I have use thus far is loading some lookup data in a background thread while users are logging in, and used the threaded debugging output (debug to file, GUI and console) all at once without degrading application speed. All debug output is cached output (except for console) and thread safe - works perfectly under our test systems (Windows and Linux).

But yes, I am very eager to switch to FastCGI, to help manage open database connections (normally the slowest code in any desktop/web app).

Marcos Douglas wrote

BTW, is tiOPF life?

Not 100% sure what you mean. Maybe "is it alive?" If so, yes tiOPF is still actively being used and developed. A new branch was started recently to work on tiOPF3 features which will include Unicode support (but FPC is lagging behind Delphi on that one now).

tiOPF2 is very stable for many years already - hence the reason there are less commits than say 5 years ago, but that is just a sign that framework+applications are working well, not that tiOPF is dead.

OK Lee, I will wait a public release, thanks.

Sorry my bad english :( but you get: "is it alive?" Thanks for the information about tiOPF!

Marcos Douglas

from the documentation of ExtPascal:
file:///C:/ExtPascal/help/Overview.html (bottom part) the Parser can be adapted to read the documentation of another JavaScript framework, Dojo for example.

Duilio

Hi Duilio,

duilio foschi wrote

from the documentation of ExtPascal: file:///C:/ExtPascal/help/Overview.html (bottom part) the Parser can be adapted to read the documentation of another JavaScript framework, Dojo for example.

Yes, he can, but the code generated contains the same classes and methods of ExtJS. So, if we adapt ExtPascal for other JS frameworks, the code would be very different... in other words, the framework Pascal do not be homogeneous for many JS frameworks.

Marcos Douglas