Archive for June, 2006

ExternalInterface Slower Than getURL

June 25th, 2006

The test page speaks for itself. Basically, I wanted to see whether it was worth using ExternalInterface for Flash-to-JavaScript communication when the JavaScript function doesn’t return anything.

It turns out getURL still has its advantages. My results from this test show the following:

10000 ExternalInterface calls: 1593ms.
10000 getURL calls: 83ms.

That’s pretty significant. My theory for the difference in execution speed is that ExternalInterface is waiting for the JavaScript function to finish executing before it allows the next call to take place. With getURL, I believe it is leaving it to the browser to queue up those JS calls, and doesn’t bother waiting for a return value.

In my test case, all the JavaScript function does is assign a variable, so it executes pretty quickly. However, in real life, a slow JavaScript function could have your ExternalInterface calls waiting for a return value that never comes.

Flash RIA Testing Effort

June 20th, 2006

Yesterday, in my post “Why a Flash vs Ajax Debate?” I talked about how targeting an older version of the Flash player in the development of RIAs can yield a multiplication in testing effort as compared to their Ajax counterparts. See the original post for more detail, but basically this is because you have to test every minor Flash Player version back to the targeted version, on every browser, in order to make a cross-platform compatibility promise.

This prompted some great comments regarding QA methodologies for Flash, and I would like to hear more.

I’ll start:

When developing solo, I test heavily on all major revisions of the Flash
player back to the targeted version. If I am targeting Player 6, I also
pay special attention to 6 r47. I spot-check a few minor revisions between
each major version.

My testing for browsers mirrors typical user
agent statistics: 85% IE PC, 10% Firefox, 5% everything else.
In other words, I test heavily on IE PC and spot-check virtually everything
else, with a little extra attention paid to Firefox.

This ends up being a manageable testing effort for solo development, and very few bugs have ever made it through. With JavaScript, the testing is usually similar, except that the Flash player is not a factor at all. I pay a little more attention to IE 5.x and Safari because of differences in their JavaScript implementation, but usually those differences are handled by a framework and don’t present much of a problem.

Though my thoughts so far have been focused on the code behind the scenes, I would be remiss not to point out that one place where Flash can unquestionably reduce the QA effort is in the UI. Rendering differences between Flash player versions are almost nonexistent. In fact, this is one area in which I have come to take Flash for granted – you forget about the UI if it’s not causing you problems. Getting complex components to work identically everywhere is not always a sure thing, but you can be guaranteed that they’ll LOOK the same. Compare/contrast with HTML/CSS, and Flash clearly comes out the victor on that score.

So, what Flash player/browser combinations do you test in? What known issues do you specifically look out for? If you’re an Ajax developer, what frameworks do you use, and which browsers do you test in? This promises to be a great discussion and one well worth having.

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Why a Flash vs Ajax Debate?

June 19th, 2006

I’ve been wondering for a while why Ajax has become so popular recently, when Flash has had the same capabilities and more for several years. I’ve been working with both JavaScript and Flash since 1999, and for me, there’s never been a debate over which was the superior technology. I avoided JavaScript when possible, mostly because cross-platform compatibility was my prime directive, and because it was possible to do things in Flash that JavaScript was incapable of. For a long time, the Flash Player was more ubiquitous than the presence of advanced JavaScript capability.

Today it seems to me that the Flash Player and advanced JavaScript capability are almost on an even footing in terms of ubiquity (I say this based on user agent stats I’ve seen from a few different market segments). When you consider that MSIE 6 can make up 90% of the traffic to a consumer-oriented site, that’s a pretty good chunk of it. Then, you’ve got the IE 5.x’s, the Firefox’s and the occasional Safari. Really, the browser that can’t do Ajax is increasingly rare.

I still believe Flash is superior, in many ways. But ironically, the things that used to be its main strengths are becoming liabilities.

I used to rely on Flash because it reduced my testing effort. With Flash, I could be basically assured that what worked on PC IE would work on Mac IE (no small feat, by JavaScript standards). Unfortunately, over the last several versions of the Flash Player, many obscure bugs have come and gone, bugs that existed for perhaps only one minor version of the Player on one browser. I recall one particularly egregious bug in Player 6-dot-something for Mac IE, where you could not cancel a loadMovie request once it was made (hogging up bandwidth to an unusable degree, in my case).

Fortunately, Macromedia was great about fixing those bugs. Unfortunately, the public was not so great about updating their players. These days, if you want to reach that 97% audience that Adobe advertises, you have to target Player 6. I recently came across a scenario where the company-wide IT policy was Player 6, no hope of upgrade (in some companies, shockwave is just completely blocked at the firewall level).

[As a long-time Flash devotee, I cringe while writing the following]

The upshot of all this is that Flash represents a multiplication in testing effort for every back-version you target. Even some of the simplest tasks, such as Local Shared Object read and write, can not in my experience be relied upon to work identically across all minor player versions back to 6.0. If you want to make a compatibility promise, the only way to do so is to test every feature of your application in every version of every targeted browser, in every minor version of the Flash player going back to the targeted version.

To put that in perspective, there are 6 releases in the Player 6 archive, and Player 7 had 7. Let’s ignore Player 8 for now. Let’s suppose we want to target MSIE 5 and greater, Firefox 1 and greater, and Safari 2 and greater. That’s at least 3 versions of IE, at least 3 of Firefox, and probably 2 of Safari (I’m speaking loosely here, I’m sure there are more). That makes 8 browsers to test on, and 13 versions of the player – a total of 104 test configurations.

Yikes.

No development team in their right mind would take on such a testing effort, even for a mildly involved project. (Now, I’m not suggesting that you have to – you can definitely achieve high quality products in Flash without all that. But to be precise, you can’t make a cross-platform compatibility promise without actually testing on all targeted configurations.) Compare this to JavaScript, where you have only the browsers themselves to concern yourself with.

Now, I have never tested a complex application in every minor version of the Player, and more often than not, the cross-platform compatibility promise of Flash does hold true. But I have also had situations where bugs didn’t present themselves until the product was launched and customers complained. Those situations have made me very cautious, and even though I don’t test all the minor versions, I do end up with longer QA cycles on my Flash projects than the JavaScript ones.

Not that testing JavaScript-based apps is easier: there tend to be more unanticipated bugs than in Flash, so I probably end up with more QA cycles.

Ultimately, Flash can still do way more than JavaScript, and I firmly believe it remains a better solution for RIA. But I don’t think Adobe can rightfully trumpet cross-platform compatibility and player ubiquity in the same breath. If you want all the considerable advantages that the Flash Player has to offer, you have to sacrifice some market penetration. If you want 97% reach, you have to author for Player 6 and test like mad.

One thing Adobe could do to help the situation would be to publicize the bug databases from old releases of the player. That would at least allow us to know what we’re dealing with when developing for older player versions. A lot of the bugs that have given me the most grief in the past were only documented in the Flashcoders archives, and only in the ad hoc format of a discussion thread.

I have had a hard time understanding why so many developers were so keen to jump on the Ajax bandwagon when Flash has been around so much longer. Maybe this testing effort thing has something to do with it. Am I onto something here?

Flash Bug – Contents of TextField w/autoSize = true Scroll When Selected

June 19th, 2006

This one’s for Mark Wubben of SIFR fame -

When you create a multiline TextField and set its autoSize = true, the TextField should expand to accomodate its contents, and the contents should not scroll when selected by clicking and dragging within the text field. However, sometimes when you select the text, it scrolls and the top gets chopped off. This seems to happen most frequently when the mouse exits the TextField at the bottom edge, rather than the right edge.

The best solution I have found for this is not to use the autoSize property at all, but rather to simulate it, and add a little extra height:

myTextField._height = myTextField.textHeight + 7;

7 seems to be the magic number. This is just enough extra padding to prevent the scrolling, and is only a pixel or two taller than the autoSize = true version. 7 seems pretty aribitrary, and the difference between the autoSized TextField and the non-autoSized TextField varys with font face and font size. So, I use 10px to be on the safe side. I’ve tested this with a lot of different font faces and sizes, and it hasn’t failed me yet. To maintain an accurate visual representation, I subtract 10px from the height of the containing object (in the case of SWF Headings, its the ActiveX object or plugin, but it could also be a masked movieclip).

Here’s a test case, and the source as well.

[Edit: in the test case, the TextField on the left is autoSize = true, the one on the right has the workaround applied ]

More About Failing Eolas Patent Workarounds

June 14th, 2006

I happen to be one of those lucky people for whom the Eolas workarounds do not always work. The issue for me is that if I clear IE’s cache and then visit an Eolas-remediated site, the workarounds fail. If I restart the browser after clearing the cache, the workarounds are fine. Not all of my PCs exhibit this behavior.

I found the following article which says essentially that the problem may be due to a faulty installation of the Eolas patch:

http://blog.metawrap.com/blog/MicrosoftsEolasActiveXPatchForIESometimesBreaksJavaScriptWorkaround.aspx

Awesome article. Too bad I can’t uninstall the patch to prove the theory. Windows gives me Access Denied errors, and won’t even let me do System Restore to a date prior to the Eolas patch. I feel a rant coming on…

But I’ll spare you my feelings on Mac v. Windows. I think I’ll instead keep an eye out for a JavaScript tweak to fix the issue, although at the moment I’m feeling very doubtful that such a critter exists.

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A Sad Day on Flashcoders – Update

June 14th, 2006

As of about 6 PM yesterday, Flashcoders is offline. Maybe it began loathing what it had become and decided to end it all? Start casting your votes – if Flashcoders was standing on a ledge, would you

a) Talk it down – it has so much to live for

or

b) Give it a nudge?

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A Sad Day on Flashcoders

June 13th, 2006

Today was a dark day in Flashcoders history. I counted no fewer than 45 posts on the topic of “Flash coders content degrading” today, and this was a carry over from yesterday. Many of these posts were multi-paragraph rants regarding noobs, RTFM & Googable questions, the place of newbies in the mailing list ecosystem, elitists, etc. The tone of the posts ranged from irate to juvenile to jovial to concerned. The vitriol spilled into other threads as well, with accusations being hurled as to who did and did not Google or read the Help manual before posting. Scorn was heaped, soap-boxes were stood upon, and real questions went unanswered.

I resisted the temptation to voice my own opinion, except to defend one hapless soul who happened across Micael Stuhr’s inbox at the wrong time. But my hackles are up, and this blog is the correct forum to voice my opinion, and so here it is:

The only people degrading the content on Flashcoders are the ones who post messages about people degrading the content on Flashcoders, and the occasional “joke of the day”. What about the noobs and all their silly questions, you say? I believe there is no such thing as a stupid question, as long as it is sincere. I have learned more from answering “newbie” questions, and from reading answers to “newbie” questions than I have learned from almost any other source. Anybody who thinks they’re above “newbie” questions simply doesn’t see the benefit they can gain from a review of the basics.

Like many others, I love Flashcoders for its potential to provide answers to really difficult questions. But I recognize that some of the very people who today are asking “simple” questions are the same ones who will be answering hard questions in the future. Over the years, I have watched some great minds at work on Flashcoders, many of whom no longer post to the list. Today, those guys are legends in the Flash world, and probably busier than hell.

Who has taken their place? From today’s conversation, it looks like their places are empty.

So, what can be done? Stacey Mulcahey issued a call to save Flashcoders, but then promptly disappeared from the scene. (I don’t mean that as a personal attack on Stacey… it’s just that 1) I love her blog and have been looking for an excuse to link to it, and 2) I was right there with her and a little disappointed not to see her on Flashcoders anymore). She’s not the only one who complained and then dropped out of site. But if you want to save Flashcoders, you can’t abandon it.

Here’s what can be done: do not respond to off-topic messages. There are those who will… Ignore them. With regard to newbies and RTFM questions: either answer the question, or do not answer the question. It seriously does not take long to determine if a question is of interest to you.

The key thing to remember is this: it is not your civic duty to reprimand anyone for OT, RTFM, or anything else. You are not the OT Police. Dave Watts is pretty much the only person who can be attributed that title, and he seems disinterested in the job.

I know this is an idealistic approach, and not likely to reduce the amount of OT. But it WILL cut the amount of OT about OT, and that actually seems to be more of a problem these days.

Shared Libraries – Branden Hall's Original Solution

June 12th, 2006

I was researching shared fonts for my SWF Headings library, and I kept coming across references to a post on Branden Hall’s blog where he found a slick way to allow dynamic creation of elements from shared libraries. Alas, the post no longer seems to exist anywhere on his blog.

Finally, I found this post on Flashcoders which contains a sizable excerpt:

http://chattyfig.figleaf.com/pipermail/flashcoders/2002-August/045588.html

Interesting technique. Not sure I’ll be able to use it, but good to have in the arsenal just the same.

[Edit] Found a more complete writeup elsewhere on Flashcoders: http://chattyfig.figleaf.com/pipermail/flashcoders/2004-June/115662.html

[Edit] Naturally, the Wayback Machine is the first place I should have thought to look:
http://web.archive.org/web/20021206180401/http://www.waxpraxis.org/archives/000062.html

Flash 8 ColorMatrix Explained

June 9th, 2006

Here are a couple sources I found really useful in understanding the ColorMatrix class:

http://www.adobe.com/devnet/flash/articles/matrix_transformations_04.html

http://chattyfig.figleaf.com/pipermail/flashcoders/2005-September/150592.html

These were simple and straightforward, unlike many of the articles on ColorMatrix that assume you have prior knowledge of matrices in general. Also, much better than the help docs on this topic.

JavaScript – Concatenating NodeLists

June 8th, 2006

In JavaScript, you cannot concatenate two nodeLists using Array.concat(). This is because nodeLists are not true Arrays, they are more like Objects that happen to have a length property. Here’s an example scenario:

var pElements = document.body.getElementsByTagName(“p”);
var divElements = document.body.getElementsByTagName(“div”);

// This results in a new array where the last element is the entire
divElements nodeList
var pAndDivElements = pElements.concat(divElements);

As a workaround, I wrote a quick method that will join two nodelists:

joinNodeLists: function(list1,list2){
var i = list2.length – 1;

do{ list1[list1.length] = list2[i];

}
while(i–);

return list1;
}

Note that I use list1[list1.length] = list2[i] instead of list1.push(list2[i]). This is for compatibility with IE 5.

To Do: Make a function that accepts an unlimited number of nodeLists and joins them all.