When is setting pointers to null usefull ?

If you are just curious or need to profile your application, there are some debates :

• Cedric Beust
• IBM DeveloperWorks Garbage collection and performance
• And the big thread from TSS

There are some free profiling tools out there for Eclipse and NetBeans, more on this later.

Validating web.xml : mime type error

If you ever try to validate the default web.xml Tomcat’s file : you will notice that there are errors due to a wrong pattern used in the Sun’s web-app_2_4.xsd schema.
The pattern doesn’t support the “+” used in application/mathml+xml or application/rdf+xml.
This isn’t quite an issue, because you just don’t really need to validate it. But since I use Eclipse : it runs validation easily and once it catch an error, it stay with an annoying red cross. Then, I had to make a local catalog of schema so I can validate off-line.
So,once I had the schema locally,it was easy to locate the buggy pattern and add the missing part (in bold) :
<xsd:pattern value="[\p{L}\-\p{Nd}]+/[\p{L}\+\-\p{Nd}\.]+"/>

Local XML catalog

Because I am not always connected, I need to set up a local catalog of XML Schema (DTD, XSD and RelaxNG) so I can still validate my XML files.
The entries in the catalog allow you to map an URI (path to your local file) to a key of type “Schema location” (generally the file’s URL : http://…) This is the basis, but you can do smarter things. I will try for a next post.
I found some informations but no real consensus about how to set up such catalog. The problem is where to put the catalog file, where to put the shema and if possible find a convenient tool to manage the whole …
Here is what I found for now :

• The environment variable is XML_CATALOG_FILES
• The default catalog is in /etc/xml/catalog.
• Finally, the shema could go to /usr/share/xml/ or /etc/xml/dtds …

This is mainly what can be found in the Debian XML Policy.

Some references :

• http://xmlsoft.org/catalog.html Explainations + a command line tool to add/remove entries in the catalog.
• Eclipse WebTools supports XML Catalog. Go to Window / Preferences then Web and XML/ XML Catalog, there you can easily add local schema and they took priority over the online ones.
• Many references in the Cover Pages (OASIS)

Open Source ports for MacOSX

Update : 17/09/2006 : MacPorts !
I needed lftp (an efficient ftp program) on my Mac. I found several “Ports projects” : Fink (deb packages) ; MacPorts.org (ex DarwinPorts.org) and DarwinPorts.com (Source based.) The first (.org) is part of OpenDarwin.org and the second (.com) is more young, more uptodate but more uncertain too.
I choose .org and it went quite well :

1. Install XCode tools (the installer was on my HDD anyway)
2. download and install DarwinPorts click, click …
3. create a .profile in your home directory
   # For DarwinPorts
export PATH=$PATH:/opt/local/bin
export MANPATH=$MANPATH:/opt/local/share/man
export INFOPATH=$INFOPATH:/opt/local/share/infoexport
   Now you see where it is installed : /opt/local/
4. Type : sudo port install lftp in a terminal and your done.
5. To keep it up-todate put this in crontab sudo /opt/local/bin/port selfupdate
sudo /opt/local/bin/port upgrade installed .

Note that the basic utilities are already in MacOSX. And if you can purchase a MacOSX Server, you will get MySQSL, Postfix and so on with nice GUI to configure them !

Finally, some ships MacOSX binaries, more or less integrated. This leads to some forks, like Camino wich is a Firefox cousin or NeoOffice an OpenOffice twin.

MacOSX environment variables

How to set the environment variables in MacOSX : it is all there Runtime Configuration Guidelines
I still wonder how to set system wide environment variable (for the mysql “user” for example) I guess it may be in the startup scripts (BSD.)
How to open an hiden folder with finder : use the menu GO -> Go to folder

Different JVM for running Eclipse, Ant build

Eclipse has multiple relation with the JVM : there is the JVM used to run Eclipse ; the JVM used by Eclipse to compile and build your projects ; Ant’s build file can fork and use another JVM too.

• The most important and the easier : the JVM used for your projects. You can see them in Window / Preference ... : Java / Installed JREs. There you can add a new one or check the default one. Could it be override by each project ? (I didn’t find where.)
  The WebTools Platform let you choose one of those JVM to run your application server (ex: Tomcat.)
• The JVM used to run Eclipse is harder to configure ! You can get general info in help.eclipse.org.
  To know wich JVM is used go to Help / About and click Configuration Details. By default, Eclipse uses the first JVM it finds in the PATH (not JAVA_HOME.)
  So, you have to put a -vm /path_to/java argument to Eclipse. If you use MacOSX … Ctrl-click your Eclipse icon and Show Package Content ; open Info.plist and in the Eclipse node add two sibling -vm and /System/Library/Frameworks/JavaVM.framework/Versions/1.5/Home/bin/java (put them at the end and continue the numbering.)
  Note the info.plist is for Eclipse arguments only, for the jvm they can be put in MacOSX/eclipse.ini (still in the Package Content.)
• Ant too can launch a task with a different JVM : look at the java task. You can use the jvm attribute :

  <target name="start.tomcat">
      <java classname="org.apache.catalina.startup.Bootstrap"
              jvm="/System/Library/Frameworks/JavaVM.framework/Versions/1.5/Home/bin/java"
              fork="yes">
          <jvmarg value="-Dcatalina.home=${tomcat.home}"/>
          <arg value="start"/>
      </java>
  </target>

WordPress plugin : Ultimate Tag Warrior

I upgraded the Word Press Plugin : Ultimate Tag Warrior to 2.8. This is the moment to write an article about it.
Well, her site is a mess : you will have hard time to just find the last version ! But the plugin is great.
I already explain why tags are generally better than fixed categories.
Then there are a few things to setup in Word Press in order to get the most out of your Tags.
You can get a help page on your site : WordPress/wp-content/plugins/UltimateTagWarrior/ultimate-tag-warrior-help.html.

In the default sidebar, you should add :
<h2>Tag cosmos</h2>
<?php UTW_ShowWeightedTagSet(sizedcoloredtagcloud); ?>

I found some hints about how to change the templates in Jarrod Trainque’s blog.

I show the “related posts” when a single post is selected : (in post template)

<?php
 if (is_single()) {
   echo "<p><small>Related posts :<ul>";
   UTW_ShowRelatedPostsForCurrentPost("posthtmllist");
   echo "</ul></small></p>";
 }
 ?>

Note : to change the templates : go to Presentation / Theme Editor. Depending on your template, you may choose different presentations.

Finally, I set up a “tag cosmos” page : in the “Page Template”, I put after <div class="entrytext"?> this dirty hack :

<?php if ($post->ID==85) { ??>
   <p style="font-size: larger;"?>
      <?php UTW_ShowWeightedTagSetAlphabetical(sizedtagcloud); ??>
      <?php UTW_ShowWeightedTagSet("weightedlongtail") ??>
   </p?>
<?php }else { ??>
normal content ...

where 85 is the ID of a fake page I created. (replace with your own page ID.)
Then I put a link to this page in the “Tag cosmos” title of the sidebar.

del.icio.us tool : direc.tor

del.icio.us direc.tor is an AJAX based prototype for an alternative web-based rich UI to del.icio.us.
This tools is a first step towards what delicious and many tag based application are lacking the most : a good tag manager, so you can get the most of your tags.

Delicious tool : Revealicious

Revealicious is a set of graphic visualisations for your del.icio.us account that allow you to browse, search and select tags, as well as viewing posts matching them.
Well, not finished yet, they should improve the design for better readability.

A List Apart

There is a new version of the site : A List Apart : For people who make websites. The design is great and it is great under the hood too : CSS+XHTML, Ruby on rails and MySQL.
The articles are good : they really know the differences that make a site “Professional”. (By the way, I read that eBay is lagging.)
This week’s article is about javascript logging with fvlogger. It is shown as a debugging tool, which I think it is not ! (Venkman is, but only on Firefox/Mozilla.) But it is not a logging tools too, I would expect it to write logs in a file or database for latter research or exam.
At most, it will allow you to show messages (better than with an alert()) in a cross-platform way, if don’t wan’t to open Venkman and MS Visual Studio at the same time …
Don’t forget to check the discussions, there is a link at the end of the article, and they are usefull (and bad) comments (sdly, they are cut in pages wich I don’t find practical.)