Howto: Installing TracDiscussion

TracDiscussion allows adding discussion forums to the Trac (http://edgewall.org) system. Unfortunately, there’s not a lot of info on how to to it. In a perfect world, you’d just issue the command “easy_install TracDiscussion” and bam-you’re-done. In this world, not yet, anyway. Installing TracDiscussion requires installing some prerequisite packages. If you’re running Trac 11 or later, you don’t need […]

Android – Projection Maps explained

Android comes with the SQLite database. Although it’s a lighweight DBMS, its authors are sufficiently proud of it that instead of listing what features it has, they prefer to list what features it doesn’t! In addition to the SQL support we all know and love, Android includes some SQLite features that aren’t really well explained. First and foremost […]

Android ListViews with Checkboxes

Android has a very useful way of organizing lists: the ListView. However, it doesn’t seem to work right when you include a checkbox in the list! Actually, it turns out that it works exactly right, but only if you understand what “right” actually is. The normal behavior of a ListView item is that you can highlight it and […]

Using the Apache OpenJPA command-line tools

Stuff that’s unfortunately not concentrated into a convenient ready-to-use example in the Apache OpenJPA docs. But that’s what this blog is all about! When using the reverse engineering, schema, and other tools directly from a shell script (not Ant or Maven), the default place to get datasource definitions and related options is in META-INF/persistence.xml. This file is mandatory […]

JSF Submit-on-Enter forms

It’s not (so far as I know) officially required anywhere, but it’s a generally accepted principle that a form on a web page containing one text field and one submit button should submit itself when you type in text and press the ENTER key. A classic example of this is Google . In actuality, it isn’t quite that […]

Eclipse: Tomcat FileNotFoundException

After happily using the sysdeo Tomcat plugin for years. I’ve finally been pushed into using the Server facility bundled into Eclipse Ganymede’s JEE drop. For some reason, once started, sysdeo cannot be stopped or restarted – it loses track of the logfile classes. In theory, you just create a new server of your choice in the Eclipse Servers […]

Setter not found for property class

I hate this. Messages like this shouldn’t be permitted. The proper format should be Setter not found for property “class” In other words, a JSF tag was coded with a “class=” attribute. So actually, an even more precise rendering should be: No valid setter method exists for attribute named “class”. In a civilized world, the element name and […]

Trac: Permission denied connecting to PostgreSQL Server

Another one of those obscure things that a web search didn’t turn up. Using the “psql” command-line utility, it was possible to connect to and access the PostgreSQL Trac database. However, the webapp failed, with “cannot connect to server: Permission denied”. No amount of tweaking the firewalls or the pg_hba.conf file would help. It turns out that the […]

PrettyFaces downstream effects

Latest in the ongoing story of why even the simple things take much longer than they should: I’m working on an app where the menus generate PrettyFaces bookmarkable URLs. However, when I jump to the target page, then click on a commandLink, the secondary target page won’t post properly. When you click on the actionButton, it throws a […]