Showing posts with label linux. Show all posts
Showing posts with label linux. Show all posts

Friday, July 18, 2008

PmWiki

One of my activities these months is setting up a community-oriented wiki for the improvisational theater group Preparee (which I'll be captaining next academic year. Oh, the suspense !). I went for the PmWiki distribution, developed by Patrick Michaud. Since quite a lot of customization went into converting the base installation to a user-oriented / CMS-like system I thought I'd better share some of the tricks and snippets I've been writing.

Always check the PmWiki cookbook before you start hacking away yourself: there are tons of available recipes which might already offer the functionality you wish.

Installation is a piece of cake, it's a matter of unpacking the source files and making the right directories writable by the webserver process (by using chmod on the wiki.d directory). I installed pmwiki on a Linux box. All the further customization is done in the local/config.php file, in separate skins or on the wiki pages themselves. Make sure not to touch the files that came with the core distribution (scripts, default skin ...), it makes upgrading a lot easier. I learned it the hard way :)

Users

The first part consisted of converting the wiki into a private one with several accounts which had different permissions. Setting the site-wide privacy settings (which can be finetuned per page or group by using ?action=attr in the URL) is done in the config.php file:

$DefaultPasswords['read'] = 'id:*';
$DefaultPasswords['edit'] = 'id:*';

This only allows logged-in users to read and edit pages. The site-wide admin password is bound to one account name (mine, in this case), but can be bound to a group too.

The accounts themselves can be defined in the SiteAdmin/Authuser page, in the config file, ... I soon realised that this was cumbersome, since I had to create all of the accounts by hand. By moving the accounts to a .htpasswd file and the group definitions to a .htgroup file I was able to automate the registration process :

  • Install the excellent htpasswdform recipe. It shows regular users a change password form, unregistered users a new user form and admin users a group/user management tool. Prevent account spam by installing the Captcha recipe too.
  • New users get added to a unchecked group. They get restricted privileges. Authorizing them is simply transferring them to the users group. This allows admin to check user accounts first.
  • The next part is letting pages display different links for each group. This is done by adding some custom Conditional Markup to the config file: $Conditions['authgroup'] = '$GLOBALS["AuthList"][$condparm] > 0';
    This allows you to check a current users group by using (:if authgroup=groupname:) and thus showing different content. I managed to write a quite complicated sidebar / AuthForm chock-full of checks. Dirty, but it works wonderfully well. Other interesting checks: (:if enabled AuthId:) (:if auth admin:) (:if auth read:)
Usability

The next step was to add functionality. It's pretty easy to edit the standard edit-form GUI buttons:

$GUIButtons ['textred'] = array($ArrayCount++, '%25red%25', '%25%25', '$[Red Text]','$GUIButtonDirUrlFmt/hightextred.gif"$[Red Text]"');

Adds an extra button which allows the user to color text. Check this page for more info.

Another thing I wrote was a simple shoutbox using Fox forms. This allows people, just by using standard button interaction, to post content to a page (in this case: a shoutbox). I wrote several fox scripts to allow users with no wiki knowledge whatsoever to perform basic tasks (shoutbox, adding themselves to an event, ...) by just using buttons and standard forms. It doesn't always result in pretty code, though ...

Shoutbox

I submitted this to the PmWiki cookbook. You can find the code here. This block was implemented as a page in a permanent div block I added to my custom skin. It's pretty straightforward from there. Don't forget: do not edit the default pmwiki skin, it will get replaced by a new version on the next upgrade.

Event attending/not attending list

This one's a bit uglier:

%comment% Start enroll/disroll code '''Attending''' %comment% enrolllist '''Not attending''' %comment% disrolllist (:fox enroll:) (:foxreplace template=Site.EnrollRemove target={$FullName} put=all mark="* [[Profiles/{$$author}]]" foxsuccess='[[<<]]' foxfailure='[[<<]]':) (:foxadd template=Site.EnrollAdd target='{$FullName}' put=below mark=enrolllist foxsuccess='Attending!' foxfailure='Probleem !':) (:input hidden author value='{$Author}' :) (:input hidden csum value='is attending':) %center%(:input submit post 'Im attending':) (:foxend enroll:) (:fox disroll:) (:foxreplace template=Site.EnrollRemove target='{$FullName}' put=all mark="* [[Profiles/{$$author}]]" foxsuccess='[[<<]]' foxfailure='[[<<]]':) (:foxadd template=Site.EnrollAdd target='{$FullName}' put=below mark=disrolllist foxsuccess='Not attending' foxfailure='Problem !':) (:input hidden author value='{$Author}' :) (:input hidden csum value='is not attending':) %center%(:input submit post 'Im not attending':) (:foxend disroll:) (:foxmessage enroll:)
(:foxmessage disroll:)

As you can see, both of the buttons are in a different fox form, each with two actions: replace the current occurences of the author name on the page, and add it to the right list. Disadvantage: you can't use more than one of these on the same page, only the first will get updated. Makes you wonder ... what if people were actually good enough to simply use the edit button and add their name ? :)

Tuesday, April 1, 2008

The long dark teatime of Dist-Upgrade

Every six months, it's that time again ... upgrading to the newest Ubuntu release. I don't know which department is in charge of the release branding, but with the label for release 8.04 (The year 2008, fourth month) they have outdone themselves: Hardy Heron. I really hope Mark Shuttleworth opens an Ubuntu Zoo out there in South Africa. Screw PETA, it would be horribly nice of him. The man's been into space, is there anything he can't afford ? A couple of drakes, fawns and herons would do the trick.

Back to the dist-upgrading then. The great thing about Unix is that all of your settings are stored in a central place: the Home folder (trademark). Backing up your system is a simple matter of backing up one directory. Even if it all goes bottoms up, it's just a matter of an hour (I/O wait time, mostly) to get your system back into the exact state it was.

After the obligatory reboot - yes, the only necessary reboot is when your kernel has changed - all seemed to work, except for a few Gnome panels. I'm 23 days early, the release is still in beta, so I was expecting some trouble either way.

Let's go quickly over the big changes in this release:

  • Firefox 3 beta: A huge improvement. The overall feel is a lot smoother, pages render blazingly fast, regardless of how many flash elements, poorly structured chunks of HTML or high-resolution pictures the page holds. The interface (and the download dialog) had a necessary cleanup, and the bookmarks system is a lot clearer now.
  • Gnome 2.22: Simple, yet elegant, Gnome remains my favorite desktop manager, although I'm going to check out the spectacular-looking KDE4 too. The most noticable improvement probably is the bundling of file transfer dialogs. When you're moving a lot of files between disks, the task bar used to get cluttered with "copying files" or "moving files" dialogs. Now, they are all bundled into one convenient dialog. It's a detail, but it sure makes a difference.
  • CFS (Completely Fair Scheduler): Since kernel 2.6.23, the standard Linux schedular has switched to CFS mode, which is an intelligent way of distributing processor time over several processes. It improves desktop reaction time, and makes the overall experience of working with GUI's feel smoother. You can read the (nerdy at first glance, extremely interesting at a second look) lengthy discussion Mr. Torvalds had with the other kernel developers here.
I'm very satisfied with the new release overall ! Also, very interesting for windows users: you can try out Ubuntu from within windows now, thanks to the new Wubi installation system !

(warning: next section is extremely boring if you don't have an Intel Proset Wireless chipset in your laptop, if any :) )

And now, on to the slightly bad news: this update bricked my wireless connectivity, partially. Since the 2.6.24 kernel version, ubuntu has switched from ipw3945 to ilw3945 as kernel module for Intel Proset Wireless interfaces. This new module seems to have several quirks, which hopefully will be ironed out before Hardy goes out of beta. Here's a couple of things you can do if you're experiencing troubles with given card:
  • Launchpad #204709: Solution for network interface wlan0 changing to wlan0_rename and useless activation of eth1 after performing an upgrade.
  • This thread offers a solution which is connected to a broken CAPA implementation, but that seems to be resolved in the latest Network-Manager updates.
  • Launchpad: #210005: My bugreport about the issue

Monday, January 14, 2008

Never leave the chair

In my never-ending quest to make life even lazier than it is, I decided to fiddle around a bit with my Bluetooth-enabled phone. I have a Nokia 6600, which only downside I've found so far is it's clunky size and weight. Then again, the weight has its upsides too. Within a 10-yard radius, I'm deadly with this phone.

Back to the Bluetooth-goodness then. Although it was hyped up by the telecom sector around the year 2000, it's most common use field today is still in the business section. You've seen them, those fancy headsets. Have a look at the advert on the left. It's hard to neglect the pure joy of wearing a headset, even when you're a businesswoman with curly hair. Most people have Bluetooth-enabled phones nowadays, but don't realize the tremendous fun and excitement it brings.

For instance, I was at a concert once, and a guy in front of me was trying to capture the whole experience using his cell phone. I fail to see how much joy he would have afterwards when watching the blurry VGA 30-second clip, bundled with the sound equivalent of farts in a box, but hey, who am I to judge. He was, however, blocking my view with the desperate cell-phone waving.

So I flipped out my mobile, scanned for Bluetooth devices, and found his gadget. When I sent him the Bluetooth connection invitation, the video recording application on his phone quit. He spent the next 10 minutes figuring out what the hell happened, and I was the concert hero. Well, not exactly, at least I could see the stage again.

Today, I managed to control my Linux music player using my cell phone. Using Remuco, an open-source server/client(java) bundle, I'm now capable of switching tracks, changing the volume and rating tracks, all without leaving the chair.

And that, my friends, is holy.