Sample apps speed, etc.

[Simeon]

Hi,

Just registered, new with Laszlo.

I noticed that at least on my machine the "Contacts" sample app was running really slow.
Can this be influenced by Net access problems? Is it just me or other people experience the same? I think my CPU utilization goes to 100%.

Where can I find some examples of apps using Laszlo besides company's site?

Regards,
Simeon

[antun]

Hey Simeon

If you've just started with Laszlo then some of this may be gibberish to you, but hopefully it will fall into place.

High CPU usage is normal during View Instantiation. Basically after the swf is sent to the client, the views (the building blocks of a Laszlo app) get created. This is the expensive part of the process. The reason that the app becomes visible after the progress indicator has stopped, but continues to apply a heavy load on the CPU is because some of the views in contacts are explicitly instructed to instantiate after, using the initstage="late" attribute.

After the app is fully started, CPU usage should drop (on mine it drops down to about 2%). If you start dragging the window around a lot, then of course CPU usage will go back up (as it will if you drag anything around in your OS).

Now, the Contacts app uses what's called lazy replication, which means that views that are bound to data (i.e. the rows of contacts) are not instantiated until needed (i.e. they become visible). This is something you do when you have lots of data, and you don't want all the processing done at the start. That's why there's a slowdown when you enlarge the window.

As for other apps, right now there aren't any that I'm aware of online (we only launched the DR release a short while ago you see).

Take care,

Antun

Take care,

Antun

[Simeon]

Hi Antun,


Yes, the CPU utilization goes down after while, but generally it still goes quite high when using the app and the responsiveness is rather slow.

My PC is nothing much - Celeron at 500, but Flash is quite fast on it.

I wonder if there is a bug involved or (hope not) Laszlo client is so slow in general?

Regards,
Simeon

[antun]

Hey Simeon

A Laszlo app will always respond a bit slower than your OS - that's to be expected because it's running in the Flash client, rather than using OS APIs. Remember that pulling down a menu within a window that's running a Laszlo app (as in Contacts) is going to be much heavier on the processor than pulling down a the File menu in your browser or word processor, because the browser/wp is making use of the OS's menu, not one being rendered in the Flash client.

There does appear to be a bug with mode management in contacts, which means that if you open up the properties dialog box, then close it, it retains the mode, so the first click back on the main window gets treated as a focus click. This makes it feel to me that my clicks aren't even being caught.

How are the other sample apps running?

-Antun

[Simeon]

Hi Antun,


>A Laszlo app will always respond a bit slower than your OS - that's to be expected because it's running in the Flash client, rather than using OS APIs.
I understand, it's just that the delay looks a bit too much, just on the edge when it feels unresponsive.
I kinda hoped that this is a debug code and the release one will be better.

>How are the other sample apps running?
Weather applet looks and behaves best (I assumed that some of the delays are done on purpose ;-).
Chat - nobody to chat with so I can't really tell. And the UI is very basic anyway.
TicTacToe is behaving well.
I was moslty interested in Contacts, because first it closer to real life applet, and second - it's very close to something we need in one of my current projects.
Yes, I noticed that there are some bugs in it, not all menu items seems to work.

Regards,
Simeon

[Simeon]

BTW, is the source code for the sample applications accessible?
It will be nice a addition to the tutorials.

Regards,
Simeon

[antun]

Yes - they're packaged with your download.

Take care,

Antun

Originally posted by Simeon
BTW, is the source code for the sample applications accessible?
It will be nice a addition to the tutorials.

Regards,
Simeon

[Simeon]

Ooops, please excuse me for not doing my homework ;-(

S.