Ken Snyder

Will Mobile Devices Make Flash Stronger?

2010-03-08T16:52:39Z

Yesderday I was playing Flash games with my 5 year old on our Ubuntu desktop. As you may know, Flash support on Linux is dismal. Specifically I was using the Adobe plugin on Firefox 3.6 in Ubuntu 9.10 with a powerful NVIDIA GeForce 9600-series graphics card and a speedy Intel Core2 Duo. We played games on flonga.com.

Here are some of the problems that made games unplayable:

Gets stuck in a loop on the splash screen
Annoying flicker
Buttons don't work (e.g. clicking "Play" does nothing)
CPU usage was intense and game was slow

The problems seemed to crop up somewhat related to UI complexity, but I get the feeling that many of the problems are due to poor programming and a poor Flash implementation for Linux.

If these problems exist on powerful desktop hardware on Linux, I can only imagine the challenges of implementing Flash on Android or OSX mobile devices which have processors of 1 GHz or less and run on the equivalent of two AA batteries.

Recently I formed the opinion that mobile devices would kill flash Flash as Steve Jobs is pushing for. But playing the games made me realize that Flash on mobile could make Flash stronger!

See, I stayed away from any game that was unplayable. With a high number of users making the same choices, Flash developers and Adobe will adapt or die. Flash developers will avoid unnecessary UI complexity and slow animations. Adobe will re-factor slow code. Flash on mobile could make Flash stronger!

We've already seen that Adobe is chomping at the bit to get Flash on mobile devices; they've added interfaces for reading mobile-device-specific hardware such as accelerometers and GPSs.

Keep an eye out, especially as Mobile Flash rolls out to Android devices in the next few months.

Wrangling MS Word's HTML

2009-10-27T22:55:57Z

Oh boy.

Handling a paste from a Word document into a browser-based WYSIWYG editor is a pain in the butt. I'm using CKEDITOR, which does have a built-in tool for stripping Word's nasty HTML, but it doesn't work well. I also had no success using PHP's HTMLPurifier, htmLawed or Tidy alone.

For a taste of Word HTML, see the section following this article. If you write HTML, a little part of you will die inside every time you see MS Word HTML.

One of the hard parts is extracting ordered and unordered lists. Especially since that varies so much between browsers.

For this PHP project, I needed to accept HTML from a WYSIWYG editor to save into a CMS system. The HTML needed to be quite restricted; e.g. to disallow changing font faces and font colors. Anyway, here is the algorithm I ended up with:

Find and replace common entities that seem to get mangled in a normal DOMDocument conversion
Remove comments
Remove nested FONT tags since DOMDocument discards content inside nested FONT tags
Extract ordered and unordered lists with regular expressions
Convert B and I tags to EM and STRONG and disallow any attributes in any of those
Replace TABLE tags with a simple tag containing a css class and cellspacing of 0
Load into DOMDocument
Remove any tags not on the whitelist
Remove any attributes not on the whitelist
Disable href and src attributes that do not contain an http, https or relative link
Strip out disallowed css styles from the style attribute
Remove css classes that Word commonly uses
Dump back to HTML
Remove DOCTYPE, HTML and BODY tags that DOMDocument automatically adds
Use Tidy to clean up any additional problems, add P tags to plain text and remove duplicate white space
Remove the linefeeds that Tidy leaves (we are sending content to Adobe Flex which parses HTML but interprets all white space literally)
Remove spans that have no attributes and thus no effect
Remove empty paragraphs

It feels good to get that worked out!

Continue reading "Wrangling MS Word's HTML"

Flash's Über Compatibility

2009-10-22T22:13:58Z

Here is the HTML that Adobe Recommends to embed a flash file:

It is compatible with IE3 and Netscape 2. Really? Do we need that level of compatibility? I mean really!

And if you want something more "automated" you can use Adobe's AC_RunActiveContent.js JavaScript file. Oh boy!

So I looked at the popular video sites and their "embed source" links. All are shorter and simpler. Blip.tv was the shortest. Here is what Blip.tv uses:

More examples are below.

Continue reading "Flash's Über Compatibility"

pathConcat

2009-10-21T15:24:28Z

I developed the following php function after writing trim($path,'/') too many times. It took me a lot of iterations to pass all the unit tests, but it works with URI and file paths for all OSs. It goes as far as to account for the strange possibility of a path containing an escaped slash. It runs pretty quickly--less than twice as long as a simple use of join: join('/',$parts).

Much of the time, simply joining with a slash is acceptable--file systems and web servers treat consecutive slashes as one. When comparing two paths for equality, spurious slashes are a problem. Or when running rewrite rules, an extra slash may throw the application into an entirely different path.

function pathConcat() {
$parts = func_get_args();
$base = array_shift($parts);
$base = str_replace('\/',"\x01",$base);
$base = rtrim($base, '/');
$paths = array();
foreach ($parts as $part) {
$part = str_replace('\/',"\x01",$part);
$part = trim($part, '/');
if (strlen($part)) {
$paths[] = $part;
}
}
$fullpath = join($paths, '/');
$fullpath = $base . '/' . $fullpath;
$fullpath = str_replace("\x01",'\/',$fullpath);
return $fullpath;
}

Examples:

pathConcat('one','two','three/'); // 'one/two/three'
pathConcat('one','','two','/','three/'); // 'one/two/three'
pathConcat('http://one/','/two/','//three/'); // 'http://one/two/three'
pathConcat('/one','/two/','//three.php'); // '/one/two/three.php'
pathConcat('c:/one/two/','/../three/'); // 'c:/one/two/../three'
pathConcat("bats\\/","like","thedark"); // "bats\\//like/thedark"
pathConcat("bats\\//like","caves"); // "bats\\//like/caves"

Multiple Codebases on localhost

2009-10-19T17:13:05Z

After writing my last article about using apache's RewriteCond to work with multiple codebases on localhost, a coworker pointed out a far simpler method using apache VirtualHosts.

On my dev machine, I'm lazy about server admin and just use wamp. To work with multiple codebases below is my simple and easy configuration.

In httpd.conf:


   DocumentRoot "c:/wamp/www"
   ServerName localhost



   DocumentRoot "c:/wamp/www/app1/"
   ServerName app1



   DocumentRoot "c:/wamp/www/app2"
   ServerName app2

In hosts file (c:/WINDOWS/system32/drivers/etc/hosts):

127.0.0.1    localhost
127.0.0.1    app1
127.0.0.1    app2

Access in the browser:

http://app1/
http://app2/

It can't get much easier.