Michael Van Canneyt wrote:
I know, I develop them myself, I even write articles about them.
Oh really ?
So it is possible that you could do a Lazarus article in a Linux
magazine at some point in the future if you had the time ?
what I am proposing is keep the lazarus app... but when compiled, runs as a
javascript app without rewriting it.
That is not possible. Maybe with a 'hello world' app, but not with a
real-life application...
In software anything is possible....
Others are telling me that it is already being done....
I just want that to make the same app inside a browser...
Yes, provided you design it from day 1 as a web-app.
Yes, in todays tools, that is possibly true.
But Lazarus designs controls on a form with coordinates.... and has
events....
Please explain why that isn't possible to do a conversion of such an app
using Javascript ?
I'm not so sure it cannot be done...
ok, let us look a bit more closely at those items....
- database - all web apps, ie perl + python can access the db. It isn't
significantly
different than what we have in fpc. What I mean by this is that they use
recordsets
and database classes just like what we do.
Either you miss the point, or I explain it wrongly.
The DB API is not available in the browser.
So you need to totally implement a new database API to be able to access it
through the browser.
This cannot be accomplished with a mere recompile of a desktop app: you need
to use the "web DB API" components or whatever you wish to call it, if you
wish to access the database from within the server.
So what you are actually doing is explaining a possible solution, right ?
If the things you say are done, then a solution is possible ?
That is how I am reading what you are saying...
To make it specific: suppose you have an existing application, coded with
TDBF, accessing a dbf file. There is simply no way to just recompile this
so it works in your browser.
You'll have to replace the TDBF with something else that talks to the
webserver, which then maybe uses tdbf to access the file, and sends responses
back to the browser (asynchronously, because that is how AJAX works).
Then you must use this new component in the application, and take care
of the asynchronous nature of the AJAX process -> again something to be
changed.
yes, perfect.
You are a master problem solver !!
What is different is the rendering of the grids. They would be rendered via
javascript
instead of being rendered using the window manager api.
In regards to the database location, that just sits on the LAMP server, and
not the "database" server as we know it. It is still the same database, just
more
likely to have a web server on it as well.
Exactly. And for this you need to implement a new set of components.
So a mere recompile is not an option.
Once again, you are describing how it might be possible.
- file - files now sit on the web server in the appropriate data directory. We
might have to change program paths. Something we are already doing in the
upgrade to vista.
I am talking about access to the local file system where the browser is
running. I am talking about accessing MS-Word or OO-Writer using COM.
I am talking about registry access, or .ini file access.
You cannot do this from within JavaScript.
You can read files from the server with Javascript.
The widget set is the least of the problems. You can make any
windows app look just like a web-app. Only: no-one does.
True. Because they don't have the "Legacy" apps that we do.
We have millions of lines of Pascal code we want to port across.
Have you seen a winamp-like application in the browser ?
Skins and shaped windows and all ? I haven't.
Yes. Within Plone. It is a python based CMS.
Web simply works different than desktop.
A little different yes. But web apps are looking more and more like
native apps every day.
Morfik has a decent
approach, IMHO the only correct one, which allows you to code
your web application almost as a desktop one. But the 'almost'
is the tricky thing... You cannot completely hide the fact that
you run inside a limited browser environment.
Well you are once again saying it is possible and that there is a
"correct" way.
Excellent.
The important issues here are keeping our Legacy app codebases, and
somehow moving them into a browser.
You have identified some of the issues and suggested some very good
solutions.
Over time, it would be nice to be able to see them working.
David
