Volume 1, Who Needs Ruby? is a pragmatic, succinct guide to improving your efficiency and the cleanness of your code. Attractive to amateurs and professionals alike, The CodeIgniter Handbook isn't your usual programming book. It's short, useful and easy to read, and covers how to improve the quality of your code and the speed of your development time.

It's available to buy as a print book or an eBook. It's also much cheaper than most programming books, at only £12 (roughly $18) for the print book and £6 ($10) for the eBook.

I've had some great feedback already -- everyone appears to be enjoying it! Thanks for your support.

Purchase the CodeIgniter Handbook today!

In order to cure this ailment, I re-defined the cd command and got it to list the contents of a directory every time I change directories. It's nice to have a constant reminder of how unorganised I am.

If you'd like to have this sweetness, add this to your ~/.profile:

cd () {
  builtin cd "$*"
  ls -al
}

Then, either re-open your Terminal window or run $ source ~/.profile to load it into the shell. Happy cding!

I use memcached lots. CI has a fantastic caching driver built in (as of 2.0). Normally, the code you'll write looks like this:

$accounts = $this->cache->memcached->get('user.' . $user_id . '.accounts');

if (!$accounts)
{
    $accounts = $this->db->where('user_id', $user_id)->get('accounts')->results();
    $this->cache->memcached->save('user.' . $user_id . '.accounts', $accounts);
}

$this->load->view('accounts/index', array( 'accounts' => $accounts ));

However this quickly becomes repetitive, boring and cluttering. With a bit of PHP5.3 magic, we can create a really nice little caching helper function that cleans this code up in no time:

function cache($key, $data) {
    $CI =& get_instance();
    $cache = $CI->cache->memcached->get($key);

    if (!$cache) {
        // There's been a miss, so run our data function and store it
        $cache = $data($CI);
        $CI->cache->memcached->save($key, $cache);
    }

    return $cache;
}

Now, our cluttered caching code becomes a commendable concoction of coding culinary craft:

$accounts = cache('user.' . $user_id . '.accounts', function(&$ci){
    return $ci->db->where('user_id', $user_id)->get('accounts')->results();
});

The anonymous method you pass through will only be executed if the cache misses (i.e. there's no data under that key, or it has expired). It will be saved into the cache and return. Delicious.

Let's look at a simple view that displays some information about a user's bank account:

<div id="account">
    <h1><?= $this->bank->get($account->bank_id)->name ?> - <?= $account->title ?></h1>

    <p class="information">
        <strong>Name:</strong> <?php if ($account->name): ?><?= $account->name ?><?php else: ?>N/A<?php endif; ?><br />
        <strong>Number:</strong> <?php if ($account->number): ?><?= $account->number ?><?php else: ?>N/A<?php endif; ?><br />
        <strong>Sort Code:</strong> <?php if ($account->sort_code): ?><?= substr($account->sort_code, 0, 2) . "-" . substr($account->sort_code, 2, 2) . "-" . substr($account->sort_code, 4, 2) ?><?php else: ?>N/A<?php endif; ?>
    </p>

    <p class="balances">
        <strong>Total Balance:</strong> <?php if ($account->total_balance): ?><?= "&pound;" . number_format($account->total_balance) ?><?php else: ?>N/A<?php endif; ?>
        <strong>Available Balance:</strong> <?php if ($account->available_balance): ?><?= "&pound;" . number_format($account->available_balance) ?><?php else: ?>N/A<?php endif; ?>
    </p>

    <p class="statements">
        <?php if ($this->statements->get_by('account_id', $account->id)): ?>
            <?= anchor('/statements/' . $account->id, 'View Statements') ?>
        <?php else: ?>
            Statements Not Currently Available
        <?php endif; ?>
    </p>
</div>

This is a rather typical view; it's displaying bits of content from an object, checking for a value's existence and pulling in bits from other database tables. It's fine, but it's all a bit messy, and we're duplicating a fair bit of code. Ideally, we want our view to look something like this:

<div id="account">
    <h1><?= $account->title() ?></h1>

    <p class="information">
        <strong>Name:</strong> <?= $account->name() ?><br />
        <strong>Number:</strong> <?= $account->number() ?><br />
        <strong>Sort Code:</strong> <?= $account->sort_code() ?>
    </p>

    <p class="balances">
        <strong>Total Balance:</strong> <?= $account->total_balance() ?>
        <strong>Available Balance:</strong> <?= $account->available_balance() ?>
    </p>

    <p class="statements"><?= $account->statements_link() ?></p>
</div>

This clears up our view considerably and removes a bunch of the duplication. It also strips out as much logic as possible from the views, and can make for some very succinct code.

We're going to create an application/presenters directory, and inside there an account_presenter.php file. This file will contain the presenter class for our account object. Let's start by extracting the title:

<?php

class Account_Presenter {

    public function __construct($account) {
        $this->account = $account;
        $this->ci =& get_instance();
    }

    public function title() {
        return $this->ci->bank->get($this->account->bank_id)->name . "-" . $account->title;
    }
}

We make sure that we can access the CodeIgniter superobject in $this->ci and the account object that we're presenting in $this->account. We can then port the logic that was previously in the view into a title() method.

We can now go ahead and tidy up the information section:

public function name() {
    return $this->account->name ?: "N/A";
}

public function number() {
    return $this->account->number ?: "N/A";
}

public function sort_code() {
    if ($sc = $this->account->sort_code) {
        return substr($sc, 0, 2) . "-" . substr($sc, 2, 2) . "-" . substr($sc, 4, 2);
    } else {
        return "N/A";
    }
}

Similarly, we can tidy up the balances section:

public function total_balance() {
    return ($this->account->total_balance) ? "£" . number_format($this->account->total_balance) : "N/A";
}

public function available_balance() {
    return ($this->account->available_balance) ? "£" . number_format($this->account->available_balance) : "N/A";
}

And finally, the statements link:

public function statements_link() {
    if ($this->ci->statements->get_by('account_id', $this->account->id)) {
        return anchor('/statements/' . $this->account->id, 'View Statements');
    } else {
        return "Statements Not Currently Available";
    }
}

Fantastic. Finally, in our controller, we need to pass through an instance of the presenter rather than the account object itself.

public function show($account_id) {
    $account = $this->account->get($account_id);
    $this->data['account'] = new Account_Presenter($account);

    $this->load->view('account/show', $this->data);
}

...and don't forget to load the presenter at the top of your controller:

require_once APPPATH . 'presenters/account_presenter.php';

...and we are done!

As I'm sure you can see, using presenters allows you to tidy up your views in a really object-oriented way. It'd be great to hear your thoughts about presenters and whether or not you plan on using them.

And lots of people think I'm an idiot.

http://postdesk.com/blog/whats-wrong-with-smoking

Teenage developer Jamie Rumbelow is all for open source but argues that creating a side business surrounding a community can actually help it grow and flourish.

Read it over on .net.

In Part 1, we looked at the basics, why and how to use the config file most effectively and we built a simple example. In Part 2, we extended our config file to allow for multiple servers without changing any values. Today, in Part 3, we'll look at tidying up our config file and we'll take a look at some of the extensive hidden configuration variables.

Let's take a look at our config file so far:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/* Dynamic Configuration
-------------------------------------------------------------------*/
$ext        = ($_SERVER['SERVER_ADDR'] == '127.0.0.1') ? ‘.local’ : ‘.com’;
$base_url   = $base_url = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == "on") ? "https" : "http");
$base_url .= "://".$_SERVER['HTTP_HOST'].$ext;
$admin_url  = $base_url . '/admin.php';

/* ExpressionEngine Configuration
-------------------------------------------------------------------*/
$config['app_version'] = "213";
$config['license_number'] = "0000-0000-0000-0000";
$config['debug'] = "1";
$config['install_lock'] = "";
$config['system_folder'] = "system";
$config['is_system_on'] = "y";
$config['allow_extensions'] = "y";
$config['site_url'] = $base_url;
$config['server_path'] = FCPATH;
$config['cp_url'] = $admin_url;
$config['theme_folder_url'] = $config['site_url']."/themes/";
$config['theme_folder_path'] = $config['server_path']."/themes/";
$config['save_tmpl_files'] = "y";
$config['tmpl_file_basepath'] = $config['server_path']."/templates/";
$config['avatar_url'] = $base_url."/uploads/system/avatars/";
$config['avatar_path'] = $config['server_path']."/uploads/system/avatars/";
$config['photo_url'] = $base_url."/uploads/system/member_photos/";
$config['photo_path'] = $config['server_path']."/uploads/system/member_photos/";
$config['sig_img_url'] = $base_url."/uploads/system/signature_attachments/";
$config['sig_img_path'] = $config['server_path']."/uploads/system/signature_attachments/";
$config['prv_msg_upload_path'] = $config['server_path']."/uploads/system/pm_attachments/";

/* CodeIgniter Configuration
-------------------------------------------------------------------*/
$config['base_url'] = $config['site_url'];
$config['uri_protocol'] = 'AUTO';
$config['language'] = 'english';
$config['charset'] = 'UTF-8';
$config['subclass_prefix'] = 'EE_';
$config['permitted_uri_chars'] = 'a-z 0-9~%.:_\\-';
$config['enable_query_strings'] = FALSE;
$config['directory_trigger'] = 'D';
$config['controller_trigger'] = 'C';
$config['function_trigger'] = 'M';
$config['log_threshold'] = 0;
$config['log_path'] = '';
$config['log_date_format'] = 'Y-m-d H:i:s';
$config['time_reference'] = 'local';

/* End of file config.php */
/* Location: ./system/expressionengine/config/config.php */

This is already nice and tidy. But it'd be great to consolidate our database information in here too, wouldn't it? That way, we can change all our system configuration in one file. This is how we do it:

/* Universal database connection settings
-------------------------------------------------------------------*/
$active_group = $ext;
$active_record = TRUE;

$db['.local']['hostname'] = 'localhost';
$db['.local']['username'] = 'root';
$db['.local']['password'] = 'root';
$db['.local']['database'] = 'some_database';
$db['.local']['dbprefix'] = "exp_";
$db['.com']['hostname'] = 'localhost';
$db['.com']['username'] = 'user';
$db['.com']['password'] = 'password';
$db['.com']['database'] = 'database';
$db['.com']['dbprefix'] = "exp_";

$db[$active_group]['dbdriver'] = "mysql";
$db[$active_group]['pconnect'] = FALSE;
$db[$active_group]['swap_pre'] = "exp_";
$db[$active_group]['db_debug'] = FALSE;
$db[$active_group]['cache_on'] = FALSE;
$db[$active_group]['autoinit'] = FALSE;
$db[$active_group]['char_set'] = "utf8";
$db[$active_group]['dbcollat'] = "utf8_general_ci";
$db[$active_group]['cachedir'] = $config['server_path'].$config['system_folder']."/expressionengine/cache/db_cache/";

By extracting out the majority of the variables (the ones that probably won't change depending on environment), and then using the $ext variable to switch the $active_group, we can adjust the database connection settings automatically depending on environment. There's one more thing we need to do. Open up your config/database.php file, empty it, and give it a solitary line:

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

require 'config.php';

/* End of file database.php */
/* Location: ./system/expressionengine/config/database.php */

Now, all references to the database configuration will be brought through the DB config file from the config.php file.

Alongside the standard configuration - paths, debug settings, URLs etc - we can customise a lot of ExpressionEngine's behaviour through a little-known technique called hidden configuration variables. A quick TextMate project search for 'Hidden Configuration Variable' bears 33 different variables with which to customise behaviour. Let's look at a couple of them:

$config['allow_textarea_tabs'] = 'y';

If you wish to preserve tabs in textareas, or let the user add a tab character, rather than shift focus to the next input, you can set this config item and all textareas in MarkItUp mode will preserve their tabs. Turning it off is as simple as setting it to 'n'.

Is the automatic JavaScript login reminder in the CP annoying you? Turn it off:

$config['login_reminder'] = 'n';

Do you want your formatted text links to automatically open in a new window?

$config['popup_link'] = 'y';

I'm sure you get the idea. There's a comprehensive list of the hidden configuration variables in the user guide.

I hope that this series has taught you one or two things about customising and using your config.php file to best effect. It's a fantastically powerful weapon to have in your arsenal, and it should make creating dynamic websites with ExpressionEngine much simpler.

I've decided to go back to college and finish my education. I want to go to University, study and grow as a person. I realise that moving out so early on was a wrong choice. It wasn't a mistake; I'm very happy in Bath and I'm really enjoying my life. I just feel like I can do so much more, get so much further and grow so much more.

The problem is, I'm too late into the term to start back at college. The solution, thankfully, is simple. Take my gap year :)

So, I'm now looking for freelance/contract work, in any language - preferably PHP, Ruby or CoffeeScript - in any country. I'm a fast, able and independent developer. I love working with other people and can manage myself independently. I'm charismatic, friendly and energetic. Historically, I've specialised in CodeIgniter and ExpressionEngine development, but I'm happy to work with any other platforms. I'm willing to relocate anywhere in the world too for a few months - hell, I'd love it. I speak decent Spanish and am willing to invest time in learning any other languages.

I'm also looking for writing and speaking gigs. I want to use the next year to diversify and work on a range of different things, and I really enjoy engaging with the community and allowing my creative side to flourish.

Email me on jamie@jamierumbelow.net or telephone me on +44 (0)7956 363875. I can't wait to hear from you.

Let's demonstrate this with a quick function. Let's say we want to remove a specific element from an array. My first guess would be to write:

var arr = [ 1, 2, 3, 4 ];
delete arr[0]; // [ nil, 2, 3, 4 ]

The issue with this, of course, is that we are left with a stray nil. That's not particularly convenient if we're using the array a lot. Instead, let's write a function and patch it onto the Array class.

Array::remove = ( element ) -> 
    if (@indexOf(element)) > -1
        @splice @indexOf(element), 1

We're using the built-in splice() method to remove the element at the index of our element. That isn't such a bad first attempt, but it's not particularly terse or pleasant. Let's remove the repetition and move index's assignment into the conditional:

Array::remove = ( element ) ->
    if (index = @indexOf(element)) > -1
        @splice index, 1

We can use CoffeeScript's keyword syntax and bracketless method calling to clean it up a bit further:

Array::remove = ( element ) ->
    if (index = @indexOf element) isnt -1
        @splice index, 1

And finally we can push it all into one line:

Array::remove = ( e ) -> @splice i, 1 if (i = @indexOf e) isnt -1

If we compare this to the JavaScript it generates:

Array.prototype.remove = function(e) {
    var i;
    if ((i = this.indexOf(e)) !== -1) {
        return this.splice(i, 1);
    }
};

…it's a no-brainer. CoffeeScript is a wonderful way of making JavaScript cleaner, more concise and altogether much more pleasant to work with. I'd highly recommend downloading a copy and trying it out.

Taggable is now at version 1.4.6, which fixes some pretty major bugs and improves the intutitiveness of the tag searching. It's highly recommended you update your Taggable install to this version.

I've also updated one of my free add-ons, SP Table Select, which allows you to create dropdowns filled with arbitrary data from arbitrary database tables. Version 1.2.0 adds support for the excellent Matrix add-on. Check it out!

http://getsparkplugs.com/taggable
http://devot-ee.com/add-ons/sp-table-select