dragffy.com

Came accross the following post at:
http://www.pluralsight.com/community/blogs/fritz/archive/2007/06/19/47771.aspx

“I spent more time than I care to admit tracking down this one, perhaps this post will save someone else the trouble…

When defining a number of functions in a prototype in JavaScript, do not include a trailing comma after the last function:

MyType.prototype = {
    foo : function() {
          // ...
    },

    bar : function() {
        //...
    }, //< - fails in IE!
 }

What was especially tricky about tracking this problem down was that FireFox works with or without the trailing comma, so it only fails in IE!”

Instead of:
$(’#ranges option’).click(function() {
var val = $(this).val();
//do something with val
});

Had to change it to:
$(’#ranges’).change(function() {
var val = $(this).val();
//do something with val
});

Django is a pretty decent web framework for Python. Having brushed up on my Python programming I started to fall in love with doctests. I then went ahead and wrote about 100 lines of doctest for model in Django, then found all tests were failing because the database fixtures weren’t being loaded.

I couldn’t find out how to install fixtures inside doctests from the official documentation, I did however, come across what seemed like a web page written in Japanese. I had to skip the Japanese but figured out the code samples. Getting fixtures working with doctests in django is fairly simple - once you know how!

At the top of your doctest you will need the following two lines:
>>> from django.core import management
>>> management.call_command("loaddata", "project/fixtures/test.json", \
verbosity=0)

Replace project and test.json with your project name and fixture. Then continue with the doctests as per usual. After they are done put the following line at the end of the doctest:
>>> management.call_command("flush", verbosity=0, interactive=False)

That should be just about it

Frustrated at having to create my own drop-down country lists in CI I created a helper for it. It can even work with the CI Validation class, so if the form is submitted and fails validation when it is redisplayed the same country is selected as the form was submitted with.

Download the file MY_form_helper.php and put it in the folder: /system/application/helpers/.

Download the file countries.php and place that in /system/application/config/.

You will now be able to create drop-down lists of countries in your views like this:
< ?=form_countries( 'country', $this->validation->country, array( ’style’ => ‘width: 250px’ ) )?>

Ensure that you create a validation rule called “country” in your controller and that you are loading the form helper.

form_countries() takes three arguments. The first is the name you would like to give the select box, this is required. The second is the country to select by default - this could be something like ‘GB’, or $this->validation->country, otherwise you can leave it blank. The third argument is any additional properties to give the select box, you can leave this blank, or pass an array. In the example above we also set the width to 250x. The country chosen by the user will be returned to the script as a two-letter ISO country code, if you are validating this then you can set the min and max length values as 2, and accept alphabetical characters only. If using MySQL as your database you will get best performance by creating a column of the type char with a length of 2.

Profiling an application is a great way to see how it is performing. CodeIgniter comes with a profiling class, which you can make calls to from your controllers. However, during development I find profiling so helpful that I want it on all my pages, without having to specifically call it each time. I also want to be able to deploy my development site to a production server - making calls to the profiler throughout the controllers means I would need to edit each and every controller to make sure the profiler wasn’t active on the live server.

After much searching I discovered a better solution. This allows you to add profiling to the bottom of every page (along with its debug info and SQL query info). When you copy the dev site live you just exclude 1 file, and profiling will be removed totally. All you need to do is create a file called MY_Output.php in system/application/libraries that extends the Output core class, with the following contents:

< ?php
# /system/application/libraries/MY_Output.php
if (!defined('BASEPATH')) exit('No direct script access allowed');
class MY_Output extends CI_Output {
function __construct() {
parent::__construct();
$this->enable_profiler( TRUE );
}
}
?>


This will enable profiling output on all your pages for development and debug purposes. When you copy your site to a production server just make sure you don’t copy MY_Output.php file. I normally use rsync for copying live and just add: --exclude="MY_Output.php" to the rsync command.

The condition to using the name MY_Output.php is that you left the variable $config['subclass_prefix'] in config.php as default. This defaults to $config['subclass_prefix'] = ‘MY_’;, so if you change it you will need to alter the filename of your new class.

There was a time when I would recursively grep the contents of literally thousands of files at a time to search for particular occurances of characters. The usual starting place was something using grep, which we can time for crude benchmarking:

user@localhost$ time grep -rn 'hello' *
templates/temp.tpl:1:hello

real 1m56.190s
user 0m1.400s
sys 0m0.940s


Using Ruby to write a script, which I named Grope, I made the search process 450 times faster, reducing an operation that took more than a minute to taking a blink of an eye…

user@localhost$ time grope 'hello'
templates/festival/06/temp.tpl: 1
hello...

real 0m0.181s
user 0m0.100s
sys 0m0.070s


A trivial Ruby script for replacing any number of tabs in input.csv with a single comma and then writing it as output.csv.

The first version works from the command line and makes use of concatenating a file and piping it to a ruby command which then diverts the output in to a file, a one liner:
cat input.csv | ruby -pe 'gsub( /\t+/, "," )' > output.csv

This can be further enhanced by using the in-place-edit switch of the Ruby interpreter, editing the input.csv file and leaving a pristine copy with .bak extension.
ruby -i.bak -pe 'gsub( /\t+/, "," )' input.csv


The final version is what you might put in to a Ruby file. Although the input and output files are hard-coded, it would be trivial to allow them to be specified on the command line.

#!/usr/bin/env ruby

# Initialise a new file object that is writable
file = File.new( "output.csv", "w" )

# Open the existing tab delimited file and read each line
File.open( "input.csv", "r" ).each do |line|
  # Perform a global substitution of tabs with commas and
  # put that in the new file
  file.puts line.gsub( /\t+/, "," )
end

# Tidy up by closing the newly written output file.
file.close