Paul Herron: Articles

Fat Links in CakePHP

2008-01-20 01:31:16

Occasionally, several links are relevant to the same piece of text. The usual approach to presenting this is to apply separate anchors to individual words within that text:

There are many search engines available...

This of course makes very little sense semantically, and it might not be immediately obvious that more than one link is available.

Another option is to make a ul or an ol and place that inline within the document. That can be detrimental to the flow of the text though, and isn't really in the non-linear spirit of hypertext.

The solution below takes a fat link approach, whereby several URLs are rolled into one. An appropriate script can then extract the links and present them as a list on their own page.

There are many search engines available...

This code is written for CakePHP 1.2, and has a controller action processing the fat link before sending an array of links to the view:

[php]<?php
class LinksController extends AppController
{
   var $argSeparator = "|";

   function index()
   {
       $links = explode(';', str_replace('/' . $this->params['controller'] . '/', '', $_SERVER['REQUEST_URI']));
       foreach ($links as $key => $link) {
           // If link text is present...
           if (preg_match('^\|^', $link)) {
               $link = explode('|', $link);
               $links[$key] = array('text' => urldecode($link[0]), 'href' => $link[1]);
           // If no link text is present...
           } else {
               $links[$key] = array('text' => $link, 'href' => $link);
           }
       }
       $this->set('links', $links);
   }
}
?>[/php]

The view then outputs the array's values as an unordered list:

[php]<h1>My list of links</h1> <?php if (!empty($links)) { ?>
<ul> <?php foreach ($links as $link) { ?>
<li><?php echo $html->link($link['text'], $link['href']); ?></li> <?php } ?>
</ul> <?php } ?>[/php]

Finally, an optional extra is to declare a route to remove the need for '/index' to be included in the URL. This will appear in app/config/routes.php like so:

[php]$Route->connect ('/links/*', array('controller'=>'links', 'action'=>'index'));[/php]

Usage

Simple links

A series of simple links. No anchor text is defined, so the href is presented instead. Links are separated with a semi-colon.

http://paulherron.net/links/http://google.com;http://yahoo.com

Links with anchor text

A series of simple links with anchor text specified. A pipe symbol separated the anchor text from the link itself.

http://paulherron.net/links/Google|http://google.com;Yahoo|http://yahoo.com

Relative links

Relative links work in a similar way.

http://paulherron.net/links/Articles|/articles

Any mixture of the above

http://paulherron.net/links/http://google.com;Yahoo|http://yahoo.com;Articles|/articles

Considerations

Be warned that spammers love to get their links on websites, and this method provides an open opportunity to do just that. Think carefully about where to implement it, and keep an eye on your analytics for signs of abuse.
The syntax chosen to separate the links is important. In the above example, | and ; are used as separators. These are arbitrary; any glyphs can be used so long as they don't appear in any of the URLs you're trying to list.
For simplicity, I've presented the bulk of this code in the controller. It might be tidier to make something like a LinkComponent and simply call that from the controller.
There might be a more Cakeish way to achieve this. For example, an alternative to $_SERVER['REQUEST_URI'] could be a :links declaration in a custom route. This would grab the links string and pass it to the controller, but some tweaking would be required to stop Cake stripping out things like http:// from the links.

Managing Simple Pages in CakePHP

2007-07-15 14:12:37

As well as complex functionality like blogs or product listings, websites often need simple pages. An about us or our services page, for example, might consist of only text and images.

CakePHP has two obvious ways to set up simple pages like these. The first is to drop a view file into app/views/pages. This is quick and easy, but the page won't be dynamic and the standard URLs of /pages/about and /pages/services might seem strange when, from the user's perspective, /about and /services would be more logical.

The second approach is to set up controllers and views for the pages. The above example could use an AboutController and a ServicesController, each with their own empty index() action and an index.ctp view file. The pages are now accessible at intuitve URLs - /about and /services - and page content can easily be managed in the database, rather than being hard-coded into the view files. The disadvantage of this approach is that coding would be required to add new pages.

Alternative Approach

The best aspects of the techniques mentioned above can be combined by introducing the following:

A Page model. This will store all of the website's simple pages.
A dynamic route in routes.php. This will recognise URL requests for stored pages and route them through to the PagesController.

The pages database table might look something like this:

[sql] `id` int(10) unsigned NOT NULL auto_increment,
`title` TEXT,
`slug` varchar(255),
`content` TEXT,
`created` datetime,
`modified` datetime[/sql]

The slug field is simply the relative URL at which the page will be accessible. For example, a slug of about will be used to set up a page at http://example.com/about and a slug of services/technical will be available at http://example.com/services/technical.

A PagesController and corresponding views should be set up. A main index() action will be used to display the stored pages. Admin actions such as admin_add() could also be used to allow editing of the pages' content. It might also be worth taking a copy of Cake's core display() action from cake/libs/controller/pages_controller.php so that static pages in app/views/pages can still be displayed.

A route is then required to send requests for stored pages to PagesController::index(). To recognise which URLs correspond to stored pages, it will be necessary to load and query the Page model. This gives us a list of slugs to add as conditions to the $params array of the route. This could be done by putting the following code in app/config/routes.php:

[php]// Load details of stored pages.
uses('model' . DS . 'model');
loadModel('Page');
$Page = new Page();
$pages = $Page->generateList(null,'slug DESC',null,null,'{n}.Page.slug');

//If the URL matches the slug of a stored page, route to PagesController::index() and set $this->params['page'] to whatever the slug is.
$Route->connect ('/:page/*', array('controller'=>'pages', 'action'=>'index'), array('page' => implode($pages, '|')));[/php]

Note: It's important to retrieve the page slugs in descending alphabetical order, otherwise child pages will wrongly be routed to their parents. For example, if 'services' appears in the $params array before 'services/technical', a URL requesting 'services/technical' would be routed to 'services'.

The PagesController is then free to pick up $this->params['page'] and fetch the relevant page using $this->Page->findBySlug($this->params['page']).

Extending the Idea

This is a simple description of the technique; it could of course be extended in any number of ways. For example:

The actual page content could be stored in a separate sections table. Associations could then be set up to say that a page hasMany sections and a section belongsTo a page. This would allow any section on a page to be linked to directly, e.g. /services/technical#programming. An extension of this would be outputting an 'on this page' element which lists and links to each section on the current page.
Pages could be given a parent_id, making a hierarchical page structure possible. For example, /services could be displayed as being a parent of /services/technical.
Pages could be assigned positions on navigation menus. For example, a link to the /about page could be set to appear on the site's main navigation menu.

A CakePHP Component for the Servage SMS API

2007-06-04 01:23:52

Being a Servage customer, I'm using its SMS API, which offers two main features:

Check if a text message can be sent to a specified number.
Send a text message to a specified number.

Servage provides some example code for doing this, which I've rewritten as a CakePHP component.

app/controllers/components/sms.php

[php]<?php
class SmsComponent extends Object {

    // The Servage URL for posting messages.
    var $send_url = 'http://smsgateway.servage.net/sms.php';
    // The Servage URL for requesting coverage information.
    var $coverage_url = 'http://smsgateway.servage.net/sms_coverage.php';
    // Customer ID.
    var $customer = '00000';
    // Customer key.
    var $key = '00000000';

/**
* Sends an SMS message to the specified number.
*
* @param int $to The phone number to which the message should be sent.
* @param mixed $message The message to be sent.
* @param mixed $from The name or number of the sender.
* @param int $concat The number of messages to join when sending.
* @return boolean True if the message was successfully posted to Servage.
*/
    function send($to,$message,$from = null,$concat = 1) {
        // Add the parameters to the request URL.
        $request = $this->send_url.'?customer='.$this->customer.'&key='.$this->key.'&number='.urlencode($to).'&message='.urlencode($message).'&concat='.$concat;
        if (!is_null($from))
            $request .= '&from=' . $from;
        // Make the request.
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $request);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $response = curl_exec($ch);
        curl_close($ch);
        // Get the status from the response string.
        $result = split(',',$response);
        if ($result[0] == 'OK')
            return true;
    }

/**
* Checks if coverage can be provided for the specified number.
*
* @param int $number The phone number with international dialling code, e.g. 447796544789.
* @return boolean True if the specified number has coverage.
*/
    function hasCoverage($number) {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $this->coverage_url . '?number='.$number);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $response = curl_exec($ch);
        curl_close($ch);
        $result = split(',',$response);
        if ($result[0] == 'OK')
            return true;
    }

}
?>[/php]

Once the component is declared in the $components array of the controller, it can be used like this:

[php]// Check coverage.
$this->Sms->hasCoverage('447736044651');
// Send a message.
$this->Sms->send('447736044651', 'This is a test message.'));
// Send a message, this time specifying the sender and span.
$this->Sms->send('447736044651', 'This is a second test message.', 'graemegarden', 2));[/php]

Setting Up Domains for Local Projects on Windows Apache

2007-05-27 16:49:44

In Apache, the easiest way to set up a project is to declare its directory path as the DocumentRoot in httpd.conf:

[code]# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot "C:\Design\myproject"[/code]

That directive, after restarting Apache, would make the contents of myproject available at http://localhost/. This is fine for one project, but accessing the contents of a different project directory - say, C:\Design\myotherproject - as if it were the document root would require changing the config file and restarting Apache.

VirtualHost Saves the Day

In httpd.conf, we can first use the NameVirtualHost directive to specify the IP to which name-based requests will resolve. As we're working locally, this should be the loopback IP address, 127.0.0.1. We then give a series of VirtualHost directives to specify the domain name and corresponding directory for each project.

[code] NameVirtualHost 127.0.0.1

<VirtualHost 127.0.0.1>
DocumentRoot "C:/Design/myproject"
ServerName myproject.l
</VirtualHost>

<VirtualHost 127.0.0.1>
DocumentRoot "C:/Design/myotherproject"
ServerName myotherproject.l
</VirtualHost>[/code]

We now need to take care of the DNS part of this process. Requests for any of our test domains should map to 127.0.0.1, and this can be enforced in the Windows hosts file, usually available at C:\WINDOWS\system32\drivers\etc\hosts.

[code]# Copyright (c) 1993-1999 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
#      102.54.94.97     rhino.acme.com          # source server
#       38.25.63.10     x.acme.com              # x client host

127.0.0.1       localhost
127.0.0.1       myproject.l
127.0.0.1       myotherproject.l[/code]

All being well, this setup would make the two example projects available at http://myproject.l and http://myotherproject.l.

Apache will need a restart for the changes to take effect. It might also be necessary to restart Windows' DNS Client service, which can be found by right-clicking My Computer, selecting Manage and navigating to the Services section under Services and Applications.

Using afterFind() to create pseudofields in CakePHP

2007-05-06 15:26:48

One useful application of this feature is in merging data from two or more database fields into one pseudofield. In the example below, afterFind() is added to a User model. A foreach statement takes the firstName and lastName fields for each user and creates a new field, fullName.

[php]<?php
class User extends AppModel
{
    var $name = 'User';

   function afterFind($results) {
       // For any results returned from the 'User' model, take 'firstName' and 'lastName' and use them to produce a 'fullName' pseudofield.
       foreach ($results as $key => $val) {
           if (isset($val['User']['firstName']) && isset($val['User']['lastName'])) {
               $results[$key]['User']['fullName'] = $val['User']['firstName'] . ' ' . $val['User']['lastName'];
           }
       }
      return $results;
   }
}
?>[/php]

CakePHP makes $results available automatically, and automatically deals with them when they're returned from the afterFind(), so this function should work 'as is'.

All being well, a find(), findAll() or findBy<field>() query in the controller will now give an array structure like this:

[php][User] => Array
   (
   [0] =>
       (
       [firstName] => Graeme
       [lastName] => Garden
       [fullName] => Graeme Garden
       )

   [1] =>
       (
       [firstName] => Tim
       [lastName] => Brooke-Taylor
       [fullName] => Tim Brooke-Taylor
       )
   )[/php]

afterFind() can result in significantly tidier code, and puts this kind of processing where it belongs - in the model. It's also a useful workaround for inserting more than one field into a generateList() statement. The label parameter in generateList() can only be sourced from one field, but this can be the pseudofield generated in the example above.

[php]$this->set('users', $this->User->generateList(null,null,null,'{n}.User.id','{n}.User.fullName'));[/php]

This would set a $users array for use in the view, and could be used be used to output a select box with each option set to a user's full name.

No-Cost Computing: The Best Free and Open Source Windows Applications

2007-01-01 20:08:56

Antivirus

avast!. It's functional and updates its virus definitions regularly. This software has been keeping my computers virus-free for over a year.

Browsers

Mozilla Firefox. The fast, intuitive and extensible web browser with the increasingly large following.

Email

Mozilla Thunderbird. Like Firefox, it works a treat. A worthy alternative to Outlook Express or, coupled with Mozilla Sunbird, to Microsoft Outlook.

Environments, IDEs & Frameworks

Eclipse. This Java-based editor is great for many types of programming. I use it with the PHPEclipse plugin for my CakePHP projects.
Wamp5. Makes it possible to run Apache, PHP and MySQL on a Windows PC.

File Sharing & Downloading

µTorrent. A small, fast and user-friendly BitTorrent client.

FTP

FileZilla. An FTP and SFTP client.

Graphics & Photo

The GIMP. Rivals Adobe Photoshop in many respects. Add the UFRaw plugin for RAW image editing, but note that the program currently only supports editing at 8-bits per channel.
Inkscape. A very capable vector drawing application.
FreeMind. A Java-based application for producing mind maps. Exports to XHTML as well as various vector and raster formats.
PDF Creator. Sets up a virtual PDF printer, making it possible to save to PDF in any software that can print.
SICAT. A small executable with a very specific aim. If you want your screenshots to be automatically uploaded to your webspace via FTP, and the URL copied to your clipboard, this program is for you.

Media Players & Codecs

foobar2000. The faster-loading, faster-working alternative to Winamp, with all the useful features retained. It's also compatible with the excellent music profiling service, Last.fm.
VLC Media Player. A simple media player with many useful features. It has a wide range of inbuilt codecs and is particularly good at coping with damaged or incomplete files. It can even play media that's in a disk image (.iso) file.

Messengers & VOIP

MirandaIM. A minimalist instant messaging client that gives access to protocols such as ICQ, AIM, MSN, IRC, Yahoo!, Jabber and Google Talk. Consumes considerably fewer resources than Windows Live Messenger.

Office & DTP Applications

OpenOffice.org. A suite applications to rival Microsoft Office.
HTML Slidy. Not so much a program as a useful script, but still deserves a mention as an excellent Impress or Powerpoint alternative. Produce some slides in HTML and display them fullscreen in your browser using Slidy. Many oft-used slideshow features are emulated, including keyboard navigation and incremental display of slide content. As with any web page, Flash and other media can be embedded.

Sound & Music

Audacity. A feature-packed alternative to Sony Sound Forge.
JJ MP3 Renamer. A useful freeware tool for tagging and renaming MP3 files.

Utilities & Other

WinDirStat. Displays disk usage information graphically.
Notepad++. An excellent Notepad replacement and powerful text editor. Useful features include syntax highlighting and code autocompletion.
Startup Manager. Easy customisation of which programs run when Windows boots.
LS. A useful application for generating a list of a directory's contents.
7-Zip. A file archiver that's very similar to WinRAR. Can be used to compress and decompress RAR and ZIP files.

Video

MediaCoder. For all your video transcoding needs. MediaCoder supports a variety of video and audio formats and has an excellent interface. It supports encoding plugins for a range a devices, making it ideal for encoding video for products like the Apple iPod.
MediaInfo. Drag a video, audio or subtitle file onto the this application to see comprehensive technical details, including information on the codec, file size, duration and more.
VirtualDub. A video capture and linear editing tool.

Donate Your Carcass Online

2006-11-30 20:08:56

As someone who inadvertently destroys or loses donor cards on a regular basis, I was pleased to be referred by a friend to the NHS UK Transplant website. Because a computerised database is difficult to put through the washing machine, I feel much happier that my desire to be broken down for spares will be respected. Signing up is simple, and the questions page sums up rather neatly why this is such a good idea:

One donor can save the life of several people, restore the sight of two others and improve the quality of life of many more. The more people who pledge to donate their organs and tissue after their death, the more people stand to benefit. By choosing to join the NHS Organ Donor Register you could help to make sure life goes on for many others.

There are moral considerations. I pity the poor bastard who, medical advances permitting, inherits this brain. It's inexplicably innumerate, and prone to complete shutdown at the mere mention of the words "essay plan".

Wearing two pairs of glasses (one pair atop the other) as she awaited an emergency appointment at the optometrist's, my Year 9 classmate didn't take kindly to being called "six eyes" from across the room. I didn't say it, but evidently looked guilty enough to warrant a ferocious jab between the ribs with an HB pencil. That my liver survived the ordeal was nothing short of a miracle. If you have my liver and are reading this, please be aware that it's been jabbed very hard with a pencil.

But I digress. Indolence alone is insufficient reason for not signing up. Why not head over there now and stick your name down? In your absence, you may just be able to improve the lives of many people.

Fetch a Random Database Entry with CakePHP

2006-11-27 20:08:56

To achieve this, all we need to do is order our retrieved records randomly. We can do that by inserting the rand() function in the $order field.

To take only a certain number of these randomised entries, we can use the $limit parameter. This is set to 1 in the example below.

[php]// This statement queries a Testimonial model for one random entry. $this->Testimonial->findAll(null,null,'rand()',1,null,null);[/php]