Blackberry 5.0 devices only partially work, needs improvement

[sbelen]

Hello,

I'm trying to view the JQ Mobile demo: http://jquerymobile.com/demos/1.0a2/ on Blackberry Bold 9000 (BB5) but it only returns a white page with only the title filled in.

[toddparker]

We just tested this on our 9330 Curve and 9550 Storm 2 and both devices loaded that page correctly and I was able to navigate around. Can you re-try?

[sbelen]

Hello,

I've tried it again and it fails again.
Actually when i try the 1.0a1 demo it works fine..

Maybe this is because the proxy of my Mobile Provider is between ?

[toddparker]

Could be. Can you try it on wifi?

[DavidDeSloovere]

I'm seeing the same problem on the Blackberry simulators: https://github.com/jquery/jquery-mobile/issues/issue/478

[ry0ohki]

Seeing the same issue on the simulator and on an actual BB5 phone (Blank screen with scroll bars on demo page)

[nariman-haghighi]

There seems to be a workaround for this at least: http://forum.jquery.com/topic/i-can-t-get-jquery-mobile-to-render-on-blackberry-os-5-simulators

[johnbender]

Can you test on the lastest? Thanks!

http://jquerymobile.com/test/

[Inawire]

I still had the problem with some apps. Newest build seams to load most times for me now.

Try turning off "JavaScript Timeout" for the BB browser.
(Options - Browser configuration - Terminate slow running scripts)

Application now renders.
Note: Not a solution just an area to start looking for a solution...

I added some more on this in the thread:
http://forum.jquery.com/topic/i-can-t-get-jquery-mobile-to-render-on-blackberry-os-5-simulators

Looks like a time out issue with no warning. I'm assuming that with code optimization this might be avoided but how to handle some sort of warning when it does?

[TZAdvantage]

There is an issue where mobile providers change the contents of the html and combine css and js files to minimize requests. If you have files that have a UTF-8 signature (first 3 bytes) this will corrupt the the combined files with invalid characters in between. One solution is to combine the files on your side (don't forget to strip the utf8 signature when present) and even better when possible also compress them. In that case the provider will leave those files alone.

in c# you do something like this:
foreach (string FileName in Files) {
byte[] bytes;
if (File.Exists(context.Server.MapPath(FileName))) {
bytes = File.ReadAllBytes(context.Server.MapPath(FileName));
if (bytes[0] == 0xEF && bytes[1] == 0xBB && bytes[2] == 0xBF) {
m = System.Text.ASCIIEncoding.UTF8.GetBytes("/\r\n File: " + FileName + ". Removed UTF-8 Signature.\r\n/\r\n");
Writer.Write(m, 0, m.Length);
Writer.Write(bytes, 3, bytes.Length - 3);
} else {
m = System.Text.ASCIIEncoding.UTF8.GetBytes("/\r\n File: " + FileName + ". Unkown encoding. Writing as if it was UTF-8 without signature.\r\n/\r\n");
Writer.Write(m, 0, m.Length);
Writer.Write(bytes, 0, bytes.Length);
}

                    } else {
                        m = System.Text.ASCIIEncoding.UTF8.GetBytes("/*\r\n  File: " + FileName + ". FILE NOT FOUND!!!.\r\n*/\r\n");
                        Writer.Write(m, 0, m.Length);
                    }
                }

hope this helps to exclude some unexpected results.

[toddparker]

This is now closed with our fix that excluded BB5 from Ajax navigation, among other tweaks.

[dcherman]

This is still occurring with JQM Beta 2. I have a simple page that with a single UL, but has 50 items in the list (each containing a link element).

The page does not finish rendering before it hits the BB Browser "slow script" timeout. If I turn off that option, it works fine. If I leave it on, I get a blank page close to 100% of the time.

[ricksuggs]

I can confirm this as well, I've narrowed down my Blackberry 5.0 problem to the script terminating when processing a listview of 16 items containing links, the script repeatedly terminates after the first 6 listviews in the 'listviewcreate' event handler.

[mbernier85]

This issue should be open, try using a BlackBerry 9300 on OS 5.0 and the page :

http://jquerymobile.com/demos/1.0b3/docs/lists/lists-performance.html

The problem will occur, the javascript will timeout and show a blank page, which is not a good behaviour, we lost a good amount of time seeking the problem.

[toddparker]

Ah, well that page is designed specifically to push the boundaries of how large a page could be before it hangs. We don't recommend building a page with 400+ list items on any mobile device, let alone a BB5 device. That page is mainly there for testing.

[mbernier85]

Yeah maybe, but right now we are building a full web application, and some pages contain more than 1000 lines of html, and they hang, just like your example. It hangs at around 1500 lines.

And making the page smaller is not a possibility.

[toddparker]

Regardless of whether you are using jQM or your own homebrew JS, having 1,000 lines of code isn't going to work on some mobile devices, especially those like BB5 that have very limited amounts of RAM and slow processors. IF BB5 is a priority, you need to keep your pages really small and limit the amount of scripting overhead.

[mbernier85]

If we take off jquery mobile from the page, the page load pretty well, even with 3000 lines of code.

There are no other JS than JQuery mobile in our page right now, and when we pass 1500 lines of html it hangs, which is not normal.

I know that OS5 is a pain, but we still need to support it, and offer a minimum of feature to the user.

[dcherman]

As a workaround if it fits your use case, you can try to implement infinite scrolling on your page rather than rendering everything at once. As the scrollbar reaches some percentage of the screen, you'd load and initialize the next batch of items rather than loading everything at once.

Might file a separate enhancement for a "partial" refresh function would which enhance this even further, if it's doable.

[scottjehl]

Hey livinloud,
The problem is BB5 is known to have a very slow processor and JS parser. Our code works on BB5, as in it's functional, but it's quite slow. Even jQuery itself takes quite a while to parse before jQM even starts!

You may decide that it's better for your users to simply not serve BB5 javascript at all. If the site is built using Progressive Enhancement, that may be an easier decision to make.

In our own client work on the new BostonGlobe.com, we did just that: BB5 gets no JavaScript, but the presentation and content is still nice and functional.

We're quite open to pull requests that improve our performance, so definitely submit ideas if you have any. However, I think this is just an issue of a slow JS parser and too many jQM-driven components in your page. If you're using list views, you might try not using the list view plugin and simply serving the UL as it would be after JS manipulation. Maybe that'll ease some of the extra work jQM is doing.

On Sep 27, 2011, at 3:45 PM, livinloud wrote:

If we take off jquery mobile from the page, the page load pretty well, even with 3000 lines of code.

There are no other JS than JQuery mobile in our page right now, and when we pass 1500 lines of html it hangs, which is not normal.

I know that OS5 is a pain, but we still need to support it, and offer a minimum of feature to the user.

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