Dinamis

At Dinamis, we've put to good use several ORM's in various worlds.

Personally, one thing I find is that they are not fully object oriented. There is an atmosphere in the community around these ORMs that seem to relegate Object orientation to Inheritance. Sure, inheritance is important ... but how much ?

What I believe is fundamentally more important in an ORM and which is sadly missing, is the idea that objects are entities and that they have relationships.

First, I describe the Foreign Key, which I believe is too low-level for an object world.

Here is the original code:

That would not play at all with IE6 or 7 but it played fine with Firefox, Konqueror, and Opera. After much digging, I found SWFObject which enabled me to embed the Flash player using JavaScript. Here is the revised code:

Add the Cooker main and contrib media sources.

urpmi freenx nxagent nxproxy nxviewer libnxX11_0-1.4.0-3mdk

Disable the Cooker media sources to avoid installing other packages from the Cooker repositories. Cooker repositories should only be used in the stable (official) distro when you are absolutely certain of what you are doing. In the case of freenx, there are very few dependencies and certainly none that require upgrading critical packages like rpm and urpmi so it is fairly safe to install from Cooker.

nxserver --adduser someuser
nxserver --passwd someuser

The following is applicable to Xen 2.0.6.

1. Do a minimal install of Mandriva 2005 LE + the following packages for the sake of convenience:
* wget
* screen
* openssh-server
* openssh-clients
* slocate
* lynx
* rsync
* traceroute
* vim-common
* vim-enhanced
* drakwizard
* drakxtools
* ncftp
* lsof

If you intend to use LVM backed VBDs (Virtual Block Devices) for domU, install the lvm2 package too.

2. Go to http://urpmi-addmedia.org and configure main, contribs, and updates urpmi media sources.

Over the last couple of weeks, I have had a few mysterious crashes with Mandrake 10.1 Community Edition. When the machine became non responsive, it would not accept ssh connections, typically failing with a "no route to host" response, or even pings. There would be no video on the console and even the Caps Lock key on the keyboard would not work. I would have no choice but to hit the Reset button on the machine. The logs did not yield any useful information.

When generating a PDF using ReportLab, watch the number of columns passed to a table object. If you pass fewer than what you have defined, you will get the "AttributeError: Table instance has no attribute '_cellvalues'".

Be sure to reference the TreeView, not the ScrolledWindow or you will not be able to set_model.

Watch for http://127.0.0.1 vs. http://localhost. The two are not the same from Mozilla's perspective. I spent hours trying to troubleshoot a non-existent problem all because I was referencing 127.0.0.1 in the code and localhost in the browser. Mozilla would throw an exception: "Permission denied to call method XMLHttpRequest.open" whenever I tried do an xmlrpc request from Mozilla using the jsolait libraries. The same code had worked previously without monkeying around with signed.applets.codebase_principal_support but was failing because I was pointing the browser at localhost!

I noticed my IBM ThinPad A21p running Mandrake 9.1 was taking an inordinate amount time to boot so I paid attention to where it was stuck. The machine seemed to have hung at the "Loading sound module" step of the boot process so I just powered off and restarted the machine. This time, I got a notice that the filesystem needed checking but when I typed "Y", it complained that there was no such file as e2fsck.hda1, or something to that effect. Mandrake suggested that I should run e2fsck -b 8193 /dev/hda1. I did that but this time it responded:

I was having trouble compiling psycopg. It would link against the version of Python that was installed via RPM on my Mandrake 9.1 box, which was version 2.2.3. I knew I had to link against the latest version of Python that I had installed from source. At the recent PyGTA meeting I attended, I asked if anyone knew about compiling psycopg from source. No one volunteered an answer but the fellow sitting next to me was looking over my shoulder as I attempted various things. He noticed that I had not specified where the python executable was but had only specified the version.