Gamecreatures' Development Blog

Production gotcha: Rails send_file seems to corrupt files

admin — Thu, 20 Nov 2008 22:42:17 +0000

What’s wrong with the following Rails code?

class ResourceController < ApplicationController
DEFAULT_OPTIONS = { :disposition => ‘inline’ }

def send_file1
send_file ‘flash1.swf’, DEFAULT_OPTIONS
end

def send_file2
send_file ‘flash2.swf’, DEFAULT_OPTIONS
end
end

This code works perfectly in development mode. In production mode retrieving the two different files the second file gets corrupt / wrong…

After a long search I looked in the rails code:

def send_file(path, options = {}) #:doc:
raise MissingFile, “Cannot read file #{path}” unless File.file?(path) and File.readable?(path)

options[:length] ||= File.size(path)
options[:filename] ||= File.basename(path) unless options[:url_based_filename]
send_file_headers! options
#….
end

OOops… the send_file code modifies my class constant!
And after the first call the length and filename is placed in the class constant…
This is no problem in development mode because the classes are reloaded every time. In production mode every mongrel server has it’s own instance…

Victory: Installing JBuilder 2006 on VISTA

admin — Wed, 05 Nov 2008 22:28:36 +0000

No I really don’t like JBuilder that much. But I really hate the workspace thing in Eclipse.

The problem:
At the company I work for, we have a lot of modules written in JBuilder. The gui designer layouts are not compatible with any other IDE. Even The newest JBuilder, which simply is Eclipse doesn’t support these gui designs…
Borland: This is a VERY BAD company policy…!!!
We will migrate the GUI to netbean.. Ha!

JBuilder 2006 doesn’t work in Vista anymore
JBuilder 2006 doesn’t activate anymore

The solution for Vista Install:

Before installing disable the fancy vista layout and select classic windows (else you have invisible checkboxes in the setup)
Run setup as Administrator! (Right mouseclick exe, “Run as Administator”
Install JBuilder the normal way
Download the latest JDK1.5 and replace the JDK1.5 in the JBuilder director
In the startmenu, rightmouse click on the Jbuilder start icon, choose properties and set the compatibility mode to Windows XP. Disable visual themes. And enable ” Run as admninistrator”

The solution for activating:

Make sure you have the registrationmail/file: reg674.txt
Copy this file in your user directory: C:\Users\username (in vista) or c:\Documents and Settings\username (in windows xp)
Set the date of your PC to the year and month you’ve downloaded the file. My working date is 25 october 2005 (I guess the activation is +/- 30 days valid)
Start JBuilder and activate with the given file
Run JBuilder and exit it again
restore the computer date
et voila.. JBuilder works !

UPDATE 2008-11-07

Working with JBuilder I found it had some redraw problems. Scrolling didn’t go wel…
I solved this by setting the following lines in the file bin\jdk.config

#vmparam -Dsun.java2d.ddoffscreen=false
vmparam -Dsun.java2d.noddraw
vmparam -Dsun.java2d.d3d=false

I found the solution for these redraw problems here.

Crash IE, slow down Firefox, with this e-mail validation routine

admin — Tue, 10 Jun 2008 14:50:45 +0000

Searching the internet I found the following e-mail validation routine:

function isValidEmailAddress( address )
{
return String(address).match(/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,7})+$/);
}

Feed the following (invalid) address to the routine

123456789012345678901234567890abcdefg

Result:

IE hangs, need a complete browser restart!! Maybe you need to be very very patient!
Firefox detects a slow script

I think this is pretty strange!!

Click the link below to test this ‘bug’:

Please crash my browser

Flash Actionscript Smooth Horizontal Text Scrolling

admin — Tue, 20 May 2008 07:23:57 +0000

Well sounds simple. But it caused me a severe headache.

I created a movieclip with a text field, that needed to scroll horizontally from left to right.
The text must be readable because you must type this word before it reaches the end…

The movieclip graphics moved very smoothly, only the textfield wasn’t.

To solve the problem I needed to perform the following operations:

Set the anti-alias method for this textfield to “Optimize for Animation”

Well that was not enough, after a lot of trying, I found out I also needed to Embed the font of the textfield, for a completely smooth animation..

Very frustrating…
And I don’t like the solution because my swf file is bigger… But it will do for now..

PHP’s Frustrating Flush

admin — Mon, 19 May 2008 10:06:51 +0000

PHP not listening when you try to flush data. Try the following, it helped for me:

@ob_flush(); // try a normal flush
flush();

If PHP isn’t flushing it could be your webserver that’s collecting your output for gzipping:

mod_gzip_on no

This worked for me..

Synchronization of calendar, contacts on my (windows) mobile, horde and thunderbird.

admin — Tue, 29 Apr 2008 22:30:15 +0000

(Sorry for the format, it’s a straight copy from my DokuWiki)

This is my situation:

* I’ve got a FreeBSD server which runs PHP, Apache, Mysql, Courier Imap.
* I’ve multiple clients which run Thunderbird as my mail client. I’m using imap for mail access
* My thunderbird clients also run lightning for agenda functionality
* I also have a mobile phone HTC Touch with Windows Mobile 6.

I would like to share my contacts, agenda items, notes and tasks with all my clients.
My phone syncs all these items.
Thunderbird only the contacts an agenda..

This document describes the installation of this system. I assume you already
have a working server like described above.

Install Horde

I downloaded the Horde Groupware Webmail Edition. WARNING this **must** be at least
the 1.1 edition. At this moment it’s still a Release Candidate. (Horde Groupware Webmail Edition 1.1-RC3)

http://www.horde.org/download/app/?app=webmail

Complete Install manual of horde can be find here:

http://www.horde.org/webmail/docs/

Summary of this setup:

* Extract this file to a web directory (horde-webmail-1.1-rc3.tar.gz)
* run the setup script: php scripts/setup.php
* build the database, enter the database settings etc.
* enter the name of your IMAP user that gets administrator rights for horde

Things to know:

* you can login to horde with your IMAP username and password
* The syncML url for horde is: http://yourserver/horde-setup-location/rpc.php
* Use your IMAP username and password for this synchronisation

Thunderbird

I assume you already have thunderbird running with lightning. I’ve got the latest versions:
Thunderbird 2.0.0.9
Lightning plugin 0.8

 * At the Thunderbird extensions site download Funambol Plugin
   * You can find it at the source:
       http://sourceforge.net/project/showfiles.php?group_id=149326
   * Choose Funambol Mozilla PIM plugin
   * I've tested version 0.4.4: Funambol-Pim-Plugin-win32-v0.4.4.xp
 * Change the config for this plugin
   * Thunderbird Menu: Extra => Funambol Plugin
   * Choose Options
     * Enter your server details:
           http://yourserver/horde-setup-location/rpc.php
     * Enter your IMAP username and password settings
     * Goto tab 'Synchronize'
       * Enable contacts, press details,
                and enter 'contacts' (without quotes) in the remote name.
       * Enable calendar, press details,
               and enter 'calendar' (without quotes) in the remote name.
       * tasks are not (yet) available :-(  too bad.

Make your phone support SyncML

Download Funambol: http://www.funambol.com/opensource/downloads.php
Tested with version: funambol-pocketpc-plugin-6.5.14.cab

  * Install this cab file on your phone.
  * Start Funambol
  * Choose Menu / Account
    * Again enter the Server and login details
  * Choose Menu / Settings
    * Enable only: contacts, calendar, tasks and notes! Disable the others!!
    * Choose Menu / Advanced
      * Enter the following names for the items:
        * contacts: contacts
        * calendar: calendar
        * tasks: tasks
        * notes: notes

This was all that it took to sync all my devices!

“2008-03-30″.to_date.to_time.tomorrow == “2008-03-30″

admin — Mon, 31 Mar 2008 20:05:31 +0000

I wrote a very nice routine which would iterate over a few days.
Today I found my loop never ending !?! And this is very scary because the routine is a background process that needs to iterate over the last x-days.

But there’s a problem when you’re living in The Netherlands and you have to use daylight savings.

Try this code:

>> “2008-03-30″.to_date.to_time.tomorrow.to_date
=> Sun Mar 30

WTF !! 2008-03-30 => Tomorrow => 30 March 2008 ?!?

I indeed complained, that time was passing so quickly. But I didn’t mean to keep it stuck at 30 March!
Oh.. I’ts only my Rails Application…

How’s this possible?

>> “2008-03-30″.to_date.to_time.tomorrow
=> Sun Mar 30 23:00:00 +0200 2008

At 30-03-2008 the clock has been set back for daylight savings. Well I assume rails simply adds 24 hours with the method tomorrow. And yesterday we had 25 hours.

More info about this bug: http://dev.rubyonrails.org/ticket/2353

My temporary solution is to add some hours to tomorrow.

>> tomorrow_time = “2008-03-30″.to_date.to_time.tomorrow + 12*60*60
=> Mon Mar 31 11:00:00 +0200 2008
>> tomorrow_time.to_date
=> Mon, 31 Mar 2008

Sometimes I hate Ruby on Rails!

why don’t we collectively protest agianst the oppression of daylight saving time?
Well Tijn, I agree!

Choosing a direction for Rich Internet Applications

admin — Tue, 05 Feb 2008 13:32:51 +0000

Currently we’re at the point of a big shift/hype of (Web) Application Development. The development of Rich Internet Applications. (RIA). A RIA is an application that runs via the web, probably via a webbrowser though this isn’t a requirement.
The idea is that RIA makes this application work like a local desktop application. This could mean the application should be capable of running offline and online.

There are severy solutions for this purpose:

Ajax Based ~ This is wat I’m used to, but it has it’s limitations.

Google Gears ~ Browser Plugin Based. Look Nice, browser plugin offline application use

Adobe FLEX/Flash ~ Via the Flash plugin that’s installed on almost every PC

Adobe Air ~ To run applications from the desktop

Microsoft Silverlight ~ Microsoft attempt to join the club

JavaFX ~ Beta, Looks nice. unfortunally I’m not a big fan of the large overhead the Java plugin has.

Ajax isn’t an ideal solution because it never gives me access to the local user’s PC and doesn’t work offline.

Now is my Problem, what direction should I choose?! Staying with Ajax for now seems like a safe choice, because it will run probably on the most platforms..

This is something that requires some good Research!

Using the h method in a controller / model

admin — Tue, 29 Jan 2008 19:09:45 +0000

The h method you use in a Ruby on Rail View, isn’t available in a model or in a controller.
That’s very frustrating. An alternative method to use is:

CGI::escapeHTML( string_to_escape )

Apache Authentication and Mongrel Cluster

admin — Mon, 21 Jan 2008 07:15:24 +0000

Currently I’m running a mongrel cluster for my rails application. This works much nicer then the FastCGI version.
There was only one problem, I had an .htaccess file to restrict access to the public directory.

AuthName "Somewhere"
AuthType Basic
AuthUserFile /home/nobody/.htpasswd
Require valid-user

The problem was I needed to enter this login data 2 times.
Well after doing some google research I found out the problem was the location of the authorizationcode. I think the .htaccess file is used by every Process of the ProxyBalancer… But I’m not sure…

The solution for this problem was to place the authorization code in the proxy balancer:

BalancerMember http://rails_site:5532
BalancerMember http://rails_site:5533
AuthName "Somewhere"
AuthType Basic
AuthUserFile /home/nobody/.htpasswd
Require valid-user
</Proxy>

That’s all ;-)