[Lazarus] Quick Video: A Web Application
mschnell at lumino.de
Wed Nov 8 12:08:13 CET 2017
On 08.11.2017 11:14, Mattias Gaertner via Lazarus wrote:
> A server is not needed. You can write standalone browser applications that work offline too.
OK. Great ! Stand alone browser based applications might be one
desirable type of application, but AFAIK, the more commonly required
type of application would be server based.
> Sigh. Michael, sometimes I got the impression you are stuck in a loop.
> Use TFPTimer and TThread.
You might be right :-)
But it's not just me, but it's based on the Lazarus claim "write once,
compile everywhere" which means that I can design and test an
application in - say - Windows (using the "RAD"-way that once has been
introduced by (Borland-) Delphi, and then tell Lazarus to create a
server application with a browser GUI by just compiling my code. In a
perfect world this should simply work, in a less perfect world, some
tweaks might be necessary to optimize the thing for either platform to
>> - Communication between the Server application and the part running on the brower via a 3rd party web server.
> There are various ways since years.
I do know. Some are depreciated, I feel at the moment WebSocktes is the
way to go.
But see above: the Lazarus user should not even see this, but the
infrastructure would organize the communication in a (as good as
possible) compatible way, by just telling Lazarus to compile the
application as a server based application with a browser based GUI
accessible via a web-server.
>> - allowing for decent Debugging in Lazarus (e.g. via an optional built-in web server, which AFAIK already is in place) .
> Server debugging is already possible. But I agree, it could be easier.
> Client side debugging is working. You can use the browser's debugger to set breakpoints in the Pascal code and step through.
I suppose you are talking about pas2js, running in a Browser, which is
perfectly viable, of course.
What I meant was debugging the server based part of the application
(which accesses an attached GUI part done in pas2js. Here (AFAIK) a
webserver unit that allows for attaching to a browser to display the GUI
while the application (i.e. the "business code") runs under Lazarus,
already is provided. so I don't assume any problems here. (While in
Delphi AFAIK, this is a major problem).
>> - Lazarus providing a GUI builder for the browser based GUI.
> That's a big topic. Some parts already work.
As I already did some research om that (some time ago) I do know that is
is a big topic :) . That is why I ask. Great to hear that it is worked
on and something already is functional.
>> Moreover IMHO a migration path from Java script in the Browser (pas2js)
>> to using WebAssembly in the Browser should be considered.
> It has been started in FPC, but no one is working on that.
So same state as since quite a while. Regarding that most decent
browsers nowadays provide the WebAssembly framework, it seems viable to
ask, but of course developing time is limited.
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