Failed image upload in Joomla 1.5

If we encounter error 403 while uploading images in Joomla 1.5, try adding these 2 lines in .htaccess:

SecFilterEngine Off
SecFilterScanPOST Off

The fix works for me.

References: http://www.dart-creations.com/the-joomla-blog/blog/media-manager-upload-failed-403-error.html

Finding files modified since a certain time

To find files in the current and its subdirectories that were modified since 1 day ago:

find . -mtime -1 -print

To find files in the current and its subdirectories that were modified since 1 week (7 days) ago:

find . -mtime -7 -print

References: http://www.mydigitallife.info/2006/01/19/find-files-that-are-modified-today-or-since-certain-time-ago-in-unix/

How to generate facebook infinite session

When developing facebook applications, we might need an infinite session that will enable us to update the app users’ profile periodically. For instance, a “Quote Of TheDay” application needs to update its users’ profile everyday with a new quote.

Here are the steps to generate an infinite session that does not expire. Note: these steps only need to be done by the developer once; no action is needed from the app users.

• Login to your own facebook account.
• Browse to: http://www.facebook.com/code_gen.php?v=1.0&api_key=YOUR_API_KEY (replace YOUR_API_KEY with your app’s API key) Click through the simple instructions on the page. After that, you’ll be provided with a one-time code like 5P4I8D .
• Invoke facebook API auth.getSession using the one-time code. The returned result will be the infinite session key.

Source of info: http://wiki.developers.facebook.com/index.php/Authentication_guide

How to stay in facebook Page context

When developing Facebook application for Pages, it is mandatory to “stay in Page context” in order for <fb:page-admin-edit-header/> to be rendered. Thanks to Thought Labs Blog, for documenting the way to do so:

you MUST add the ‘fb_page_id=[pageID]‘ URL param to the POST URL.

How to display PHP compilation errors

It’s frustrating when PHP compilation errors are not shown during development. To make such compilation errors visible on the web pages, add this line in .htaccess:

php_value display_errors 1

Alternatively, if access to .htaccess is not allowed, this PHP code achieves the same result too:

ini_set(’display_errors’,1);

Modify Tomcat startup script in Eclipse

Right-click on server’s name -> Run As -> Open Run Dialog -> Arguments

FreeRADIUS’s init script

FreeRADIUS’s init script is located at scripts/rc.radiusd of the source tarball.

How to log each MySQL query

To log each and every query executed by MySQL, simply specify “-l” when starting mysqld_safe. For instance:

/usr/bin/mysqld_safe -l ...

All queries will then be logged to <hostname>.log in the data directory (typically /var/lib/mysql).

Grails quickstart

A quick start guide to Grails

There was a period of time when Java developers can only envy the RoR developers for completing the day’s work by lunch time. Not anymore, for we have Grails to the rescue!

After exploring Grails for an hour, I’m really impressed by its fuss-free scaffolding. (In an hour, I had enough time to touch on the basics and to write this post. Ha ha ) Don’t be convinced by me, you’ve gotta try it for yourself to believe it.

Ok, first of all, we will need to install Grails, which is nothing more than just:

• Download and unzip Grails.
• Define a GRAILS_HOME environment variable to point to the unzipped Grails directory.
• Add $GRAILS_HOME/bin to your $PATH.

Installation is complete!

Now let’s begin writing our very first “real-world” application. For starters, our application will help to manage seminars and registrations. Execute these steps on your shell:

• grails create-app myapp
• cd myapp
• grails create-domain-class Seminar
• grails create-domain-class Registration
• Edit myapp/grails-app/domain/Seminar.groovy:
  • class Seminar {
    String title
    Date startDateTime
    String city
    Float cost
    Boolean mealsProvided
    static hasMany = [registrations:Registration]
    }
• Edit myapp/grails-app/domain/Registration.groovy:
  • class Registration {
    String name
    Date dateOfBirth
    String gender
    Seminar seminar
    }
    
• grails generate-all Seminar
• grails generate-all Registration
• grails run-app

That’s all the code you need to write to set up the scaffolding! Let’s enjoy the fruits of our labour by browsing to http://localhost:8080/myapp. You’ll notice this scaffolding automatically includes:

• CRUD functionalities for both our Seminar and Registration domain classes.
• In the Registration data entry page, the Seminar field is rendered as a dropdown list of all Seminar objects.
• In the Seminar data entry page, the MealsProvided field is rendered as a checkbox.

Here are some screen shots of the scaffolding:

Oh, did I mention the one hour also includes a trip to the kitchen to reward myself with a cuppa coffee?

For further reading, I recommend this wonderful and FREE e-book: Getting Started with Grails by Jason Rudolph

Tweaking browser appliance

Found a handy document on tweaking the browser virtual appliance: http://www.spywareinfo.com/articles/vmware/batweaks.php

Among other stuff, it covers:

• Enabling FireFox updates
• Discard changes after shutdown
• Sharing files between appliance and host
• etc…