Author Archive for Stefan Pantke

07
Feb

A collection of tablet devices [variations of Apple's iPad]

Since I really like the idea of tocuhscreen-only table devices, here’s a short list of products I’ve found. In case you fond more,

exoPC :: 599.- USD, 8.9” multitouch, Windows 7 oder Linux

A promissing device comes from exoPC. Here’s a video from engadget.com. The device comes with a single-core Atom N270 and plays video on its 1024×600 touchscreen quite good:

Have a look inside the exoPC: Image galery. The device is planned to be shipped March 2010. All in all, it’s quite good equipped: 2 GBByte RAM, 32 GByte SSD [4.5 GByte reserved for OS], full-size SD Card slot, Atom 270 @ 1,6 GHz, WiFi 802.11 b/g, Bluetooth, Lan 10/100, 3 x USB, Audio in/out, VGA – and an 1.3 Megapixels webcam. Compare the exoPC with other here device on this page. Product photos.

joojoo :: 499.- USD. 12.1-inch tablet-appliance

joojoo is a nice looking device of enourmous 12.1 inc size. While other system come with Microsoft’s Windows oder Apple’s MacOS, joojoo comes with its own pure browser-based environment. As far as the web-site explains, each and everything runs in a browser. Thus, joojoo doesn’t run native applications – but Flash and Java. joojoo originated from the never released crunchPad.

Continue reading ‘A collection of tablet devices [variations of Apple's iPad]‘

30
Jan

Kindle 2 isn’t a device for me – Amazon doesn’t convert math text

Some days ago, I received a Kindle 2. The device looked good and buttons and controls felt just fine.

Actually, I returned it today, since Amazon’s PDF conversion service is by no means able to convert more than trivial text.

Here is part of my input PDF, which I created using LaTeX:

Continue reading ‘Kindle 2 isn’t a device for me – Amazon doesn’t convert math text’

22
Dez

upgrade to WP 2.9 – if auto-upgrade doesn’t go auto

Yesterday, I tried to auto-upgrade to WP 2.9. I pressed the respective button and Safari presented a new page indicating a download process. Unfortunately, the process suddenly finished – with no upgrade at all.

In case you try to auto-upgrade too, here is the way to manage the task anyway:

  • - First, download the WP 2.9 upgrade archive file [download link]
  • - Unpack the archive file to a local volume [your Mac OS X system unpacks automatically]
  • - Start you FTP-client and connect to your WP virtual host [for Mac OS X, you might wish to download the FTP client Cyberduck]
  • - Finally select all files within the archive and drag them to you FTP-client’s window

Now, it’s time to run the real upgrade process. Enter this URL

http://www.yourSiteName.com/wp-admin/upgrade.php

or, if WP is installed in a folder named e.g. myBlog, enter this URL

http://www.yourSiteName.com/myBlog/wp-admin/upgrade.php

At this point, you might end up with a blank page or one, which indicates a HTTP error 500. In this case, have a look at my previous post, which provides a solution regarding PHP setting of certain providers (namely 1&1).

After that, enter one of the above URLs again. WordPress should now present a small upgrade wizard, which explains the next steps to do. A typical upgrade process should finish within a few minutes (at least mine finished soon).

21
Dez

Get schema-free within minutes using MongoDB

As me, many software developers learned the relations view of database management system: Identifiy entities, develope a database schema, normalize it and map it to a real DBMS system. That’s fine. And for many application this approach is just fine.

For other types of application, this approach tends to make development complicated.

Continue reading ‘Get schema-free within minutes using MongoDB’

21
Dez

Upgraded to WP 2.9 – and ended up with an HTTP error 500

After quite some time, I visited this my blog to apply the most recent Wordpress upgrade, the 2.9 release.

After the I finished the upgrade, the front-end rendered fine, while I constantly got an error from with ADMIN site: HTTP 500 error.

In case your site runs on a server hosted by 1&1 too, you have to do two things to get ADMIN running again:

1. Create a php.ini in WP’s root directoy and add this single line of text:

memory=20MB

2. Edit WP’s .htaccess file  and add

AddType x-mapp-php5 .php

as the very first line.

26
Feb

Flex’ mx_internal_uid considered harmful

Actually, not that harmful. But you should be aware of a special meaning of this Flex object property. Here’s the story:

Today, I tried to develop a method the create shallow and deep copies of objects. Finally, I prepared this method, initially without the line marked with __MARK__:

static private function clone( source:Object, deep:Boolean = false ):Object
  {
    if ( null == source ) {
    return null;
    }
    var copy:Object;
    if ( true == deep ) {
       copy =  ObjectUtil.copy( source );
    } else {
      copy = new Object();
      for( var key:Object in source ) {
        if (  ( 'mx_internal_uid' != key ) ) {     // __MARK__
          copy[ key ] = source[ key ];
        }
     }
  }
  return copy;
} // clone

Without the line marked by __MARK__, the method copies (more or less raw) objects, but the dataProvider-driven controls gets in trouble: List-based control add each managed object a ‘mx_internal_uid‘ to identify each data object. Thus, if you copy the ‘mx_internal_uid’ property, e.g. a DataGrid will no longer be able to distinguish the original source object or the clone(source) object.

Thus, it’s appropriate to not copy ‘mx_internal_uid‘ from source to clone.

18
Feb

InfoQ article compares Blaze DS and LCDS

In case you are interested in figuring out details of Blaze DS and LCDS or you need to compare both solution, have a look at this InfoQ article: http://www.infoq.com/news/2009/02/Blaze-LiveCycle

23
Jan

all in plain english

Wheter you need to explain a customer a modern web-oriented service, or your friend really doesn’t know what Twitter is: Here is a collection of famous YouTube video explanations. All in plain english and fun to view.

Twitter in plain english

Continue reading ‘all in plain english’

15
Jan

Flex deployment: Using the correct mime type

Fine! You just managed to finish your first Flex-base AIR application. Using FlexBuilder’s Export Release Build…., you managed to package your deployable solution into a *.air file. Finally, you uploaded the *.air file to your web-server – and your coding mates tell you that not event a bit of an installation gets started. Too bad. What happened?

Most likely, you missed to assign the correct mime-type! Don’t forget, that you need to tell browsers, that files with *.air extensions actually are Adobe AIR installer files.

If you run Apache, adding the correct MIME type is simple:

AddType application/vnd.adobe.air-application-installer-package+zip .air

As always: Big trouble, small solution.Don’t forget, that this setting is absolutely vital! You need to set it – even if some browsers might be able to run the AIR install package with it. Most browser won’t…

04
Jan

Rumsfeld’s Knowns and Unknowns

Donal Rumsfeld, US Secretary of Defense, 12 Feb. 2002, Department of Defense News Briefing:

As we know, there are known knowns. There are things we know we know.
We also know there are known unknowns. That is to say we know there are some things we do not know.
But there are also unknown unknowns, the ones we don’t know we don’t know.

Related to RIAs? No, not a bit! But strongly related to the current credit crunch or investment banking in general.

Satyajit Das’ beautifully explains the concepts of known knowns, known unknowns, unknown knowns and unknown unknowns in his great book Traders Guns & Money. For anybody, who aims to know the history and evolution of investment banking, Das’ book is a must.