Archive for September, 2008

Dokeos in Machu Picchu

September 30, 2008 Leave a comment

As I was in Cusco the other week to hold a few speeches at a 3 days conference, I took the opportunity to go to Machu Picchu. This time, I managed to walk to the Intipunku (la Puerta del Sol, The Sun Gate) and take a picture from there, wearing my wonderful – but old now – Dokeos t-shirt from the 2005 User’s Day. It’s time someone offers me a new one, really :-)

Dokeos Machu Picchu

Dokeos Machu Picchu

And for those who think I look nuts… try doing a one-day-return trip to Machu Picchu and find the time, after the guided tour, to climb the 45 minutes stairs to Intipunku under a burning sun, and then we’ll talk!

Yes, sorry, I’m hiding half of it (in my defense, it was really though seeing it on the little camera screen with the bright sun beating down on me).

Here’s a better view

Machu Picchu from below the Guard Tower

Machu Picchu from below the Guard Tower

Is respecting GPL too complicated?

September 30, 2008 1 comment

I’ve had a bunch of hunches recently about companies abusing the licensing terms of Dokeos by officially declaring (but only verbally so far) that their product (being Dokeos, but not officially) is not open-source software.

The GPL licensing makes it clear that the software derived from GPL software, or any alteration to a GPL software *must* be open-sourced, at least for the people it is distributed to. While I’m slowly starting to plan a series of legal actions, this is something I sometimes add to the bottom of my e-mails:

I’d like to take the opportunity to remind you that you are free to use the software, but that any alteration that you would redistribute needs to be made available to the people you distribute it to, and any application you would embed Dokeos into needs to be open-sourced as well. This is about the only restriction that applies to our software
but we are very strongly watching that everybody respects that. Of course, we welcome external contributions and will almost always integrate it into the main distribution, avoiding additional update costs in the long run.

It’s very sad to me to see that, with the amount of efforts we put into this software, some people still find ways to not respect the rules and selfishly profit from something that has been passed on to them along with responsibilities… This is clearly stealing intellectual property.

While I understand that some companies might have problems in their business plans with respecting the GPL (because they develop their own software and don’t want the source to be available to third parties), the rules of GPL are simple: either use it and comply to open-sourcing your code, or do not use it in the first place!

Dokeos 1.8.5 – Hoja de referencia rápida

September 29, 2008 Leave a comment

Acabo de escribir un post por mi blog en Inglés, que creo que sera de mucha utilidad aquí también. Hace mucho tiempo que quería escribir una hoja de ayuda de referencia para desarrolladores de Dokeos. Ya esta! Esta en Inglés, pero hay poco texto de toda forma. Descargenla desde el blog en Inglés:

Dokeos 1.8.5 Quick Reference Sheet

September 29, 2008 1 comment

It’s been ages since I first thought I should publish a quick reference sheet for Dokeos developers. It’s now done. It’s a first version but I think it will be really useful to new Dokeos developers. It is already useful for me (particularly for $httpHeadXtra and $htmlHeadXtra), so I don’t doubt that bit.

Dokeos 1.8.5 Quick Reference Sheet

It is published under the Creative Commons BY-SA license (Paternity, Share-Alike) and I have the SVG format locally, so just ask me for it if you want to extend it. I might pretty well extend this sheet to specific class methods (like Database and Security) in the near future, but this is a good start.

Fixing the upgrade procedure of WebCalendar 1.2 for PostgreSQL 7.4

September 28, 2008 1 comment

When trying to upgrade WebCalendar to 1.2, I fell on a series of errors due to the fact that the upgrade script relies on a dependency to PostgreSQL 8.1, which allows much more ALTER TABLE syntaxes than PostgreSQL 7.4. Nevertheless, there are ways to make it work by updating the upgrade script a little to suit the new syntax.

I’m giving bits of code here, which are directly based on the www/install/sql/update-postgres.sql script, and altered to make it work.

This script can be executed manually as many times as you want with the PostgreSQL user you use for Webcalendar. Something like

psql -U webcalendar -W webcalendar < upgrade-postgres.sql

Please note that using the “postgres” user will inevitably create permissions problems that you might have to fix later using something like:

GRANT ALL PRIVILEGES ON DATABASE webcalendar TO webcalendar;

or something more specific if that doesn’t fix it.

The “TYPE” syntax error

On line 156 of the update-postgres.sql script, you will find the following query:

ALTER TABLE webcal_user ALTER COLUMN cal_passwd TYPE VARCHAR(32);

The ALTER TABLE – ALTER COLUMN with a TYPE constraint, however, is unknown in Postgresql 7.4, so you need to change this line. Here is the code I used to replace it (quite long as you will see)

/* Query in PG 7.4 form */
/*ALTER TABLE webcal_user ALTER COLUMN cal_passwd TYPE VARCHAR(32); */
ALTER TABLE webcal_user ADD COLUMN new_col VARCHAR(32);
UPDATE webcal_user SET new_col = CAST(cal_passwd AS VARCHAR(32));
ALTER TABLE webcal_user DROP COLUMN cal_passwd;
ALTER TABLE webcal_user RENAME COLUMN new_col TO cal_passwd;
VACUUM FULL webcal_user;

The VACUUM FULL command at the end allows for a complete memory clean-up which would otherwise not happen.

The UPDATE TABLE error for webcal_user

You will find the following lines around line 305:

ALTER TABLE webcal_user ADD COLUMN cal_enabled CHAR(1);
UPDATE TABLE webcal_user SET cal_enabled = ‘Y’;

This one is easy: the “UPDATE TABLE” syntax is not allowed in PG 7.4. You simply have to remove the “TABLE” keyword:

ALTER TABLE webcal_user ADD COLUMN cal_enabled CHAR(1);
UPDATE webcal_user SET cal_enabled = ‘Y’;

The NOT NULL constraint in webcal_entry_log problem

This one seems to be a real bug somewhere in the creation procedure for PostgreSQL tables. In fact, if you look into the tables-postgres.sql file, you will find that the webcal_entry_log.cal_user_cal column has a NOT NULL constraint, while in the equivalent script for MySQL, NULL values are authorized. This is tricky to fix (and uses the same procedure as the “TYPE” syntax bugfix above. In order to place it more or less in the right place, I have tried to put it around the same line as a query on the webcal_entry_log table in the upgrade-mysql.sql script (which is around line 75, or just before a comment talking about version 1.1.0).

/* Fix not null constraint in webcal_entry_log.cal_user_cal */
UPDATE webcal_entry_log SET new_col = CAST(cal_user_cal AS VARCHAR(25));
ALTER TABLE webcal_entry_log DROP COLUMN cal_user_cal;
ALTER TABLE webcal_entry_log RENAME COLUMN new_col TO cal_user_cal;
VACUUM FULL webcal_entry_log;

The webcal_nonuser_cals.cal_is_public missing column

For some reason, the cal_is_public field had not been created by the upgrade procedure, so I had to add it manually (I did that around line 200)

ALTER TABLE webcal_nonuser_cals ADD cal_is_public CHAR(1);
ALTER TABLE webcal_nonuser_cals ALTER cal_is_public SET DEFAULT ‘N’;
ALTER TABLE webcal_nonuser_cals ALTER cal_is_public SET NOT NULL;

The webcal_entry_repeats.cal_wkst DEFAULT constraint

Around line 240, you will find the following query

ALTER TABLE webcal_entry_repeats ADD cal_wkst CHAR(2) DEFAULT ‘MO’;

Because default values constraints cannot be assigned directly in an ALTER TABLE query, you have to split this line

/* Update to upgrade in PG 7.4 */
/* ALTER TABLE webcal_entry_repeats ADD cal_wkst CHAR(2) DEFAULT ‘MO’; */
ALTER TABLE webcal_entry_repeats ADD cal_wkst CHAR(2);
ALTER TABLE webcal_entry_repeats ALTER COLUMN cal_wkst SET DEFAULT ‘MO’;

You should now be alright with the SQL upgrade procedure.


You might (but this has *nothing* to do with the above) run into an encoding problem whereby the accentuated characters are transformed into little squares with question marks. This is generally due to the fact that Webcalendar only deals with ISO charsets, while your Apache configuration might be set to a default encoding of UTF-8. Make sure there is an Apache’s VirtualHost defined with an encoding of ISO-8859-1 if you are going to use this encoding.

Dokeos in Cusco

September 21, 2008 Leave a comment

I’ll be having two speeches at a free software event in Cusco these 24, 25 and 26th of September 2008. If you would like to meet us there, please get in touch beforehand by e-mail or a comment over here.

See the official announcement for more details

Dokeos en Cusco

September 21, 2008 2 comments

Nuestro equipo (Michela, nuestra relacionista pública, y yo) estará en Cusco los días 24, 25 y 26 de Setiembre para una serie de charlas sobre software libre y estándares.

Si es que ustedes quiere encontrarnos ahí para oportunidades de negocio o de desarrollo de proyectos, este viaje es una ocasión excepcional, porque es la primera visita oficial de Dokeos a Cusco, no duden en ponerse en contacto por e-mail o móvil (1 996574247).

Estaremos listos con unos contratos de instalación y de capacitación por si acaso.

Dokeos es una herramienta profesional de e-learning (capacitación en línea).

Más detalles del evento en el cual estaremos presentes:

Categories: comercial, eventos, Spanish Tags: ,

Instalar Kcachegrind en Ubuntu 8.04

September 17, 2008 Leave a comment

Kcachegrind es una aplicación que nos muestra gráficamente el consumo de tiempo y memoria que un proceso php (función, comando) provoca a un servidor Apache. Aqui una manera facil de instalarlo:

En un terminal ejecutar:

sudo apt-get install kcachegrind
sudo apt-get install php5-xdebug

Configurar estos parametros en el php.ini o en la carpeta /etc/apache2/site-available/sitename

php_admin_value xdebug.profiler_enable 1
php_admin_value xdebug.profiler_output_dir /tmp/kcache

Donde /tmp/kcache es la carpeta donde se guardarán los archivos generados, para luego poder verlos con en Aplicaciones->Programación->Kcachegrind

es necesario que la carpeta /tmp/kcache tenga permisos de escritura

sudo chmod 777 -R /tmp/kcache

Estoy suponiendo que tenemos ya instalado el apache2 y php5 correctamente instalados.

Renaming things in a piece of software with users with habits

September 12, 2008 1 comment

One of the terrible things that happen for users, from time to time, is that their usual actions are suddendly made completely unusual by a change of version, because the name (nothing else) of their favourite feature has been changed. We understand that, and we do everything we can to avoid it, but the truth is that some of our naming conventions don’t really make sense.

For example, a “learning path” is something only a guy with a degree in e-learning understands. For everybody else, a learning path is a good old “course”, while our notion of course in Dokeos is actually some kind of a “course zone” or “activity zone”. Renaming these, when we find a really good name that doesn’t let anyone misunderstand it anymore, is one of the objectives we want to reach for versions 1.8.6 and 1.8.7. We want to make Dokeos even easier to use by renaming the non-obvious to some obvious name.

This is why you may realize, in the coming months, that some things change names. But don’t worry, the icons will remain the same, at least for the time being, until everybody gets used to the new names. Then only we might want to change the icons to refresh the look a little…

Dokeos Latinoamérica crece

September 11, 2008 Leave a comment

Gracias a la confianza de nuestros clientes, Dokeos Latinoamérica crecera de 4 a 8 empleados en el més de Setiembre. Es un gran paso para nosotros, pero quiere decir

  1. que hacemos un buen trabajo
  2. que podremos hacerlo mejor aún
  3. que podremos llegar más rápido, más alto

Esperamos llegar al nivel de pequeña empresa aca en Perú antes del fin de este año. Creo que crear esta sede de Dokeos en Perú fue una muy buena decisión, debido al crecimiento económico actual y al nivél de la educación que me permite encontrar desarrolladores de un buen nivel, lo que es fundamental en mi situación de desarrollador del negocio.

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