I looked around the web for a while trying to figure out what in the world was going on. It turns out that PHP’s default session_start will block future session_starts for the same session until the session is closed. This is because the default method uses a file on the filesystem which it locks until you close it. If you want more information on this and how to close it you can read a bit more here.

We switched over to database based sessions and it fixed it. In symfony 1.4 the default session storage uses the file system, however switching over to sfPDOSessionStorage is very easy and quick.

The promo is live here https://www.facebook.com/MichiganLottery

Unfortunately, its only open to Michigan residents.

Anyway, I picked up a Kindle Fire for Christmas and decided to use it as an eReader at least once in its life. I had remembered seeing Boomerang by Michael Lewis recommended by both Fred Wilson and Chris Dixon so I figured it must be worth checking out.

The book is a short, easy read but it offers a fascinating perspective on the global financial crisis through several different viewpoints. As Chris pointed out, theres also a couple of funny anecdotes and bizarre cultural highlights. If you have some time to kill, I’d definitely recommend picking up Boomerang and giving it a once over.

Enter jQuery UI. I happened to stumble across the jQuery UI Selectable documentation and realized it would provide a good UI experience to toggle some but not all of the checkboxes. The code to implement this is surprisingly simple:

Note: You don’t actually need the div container – that was just for JSFiddle.

<div id="checkboxes">

<table id="checkboxTable">
     <tr>
         <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
     </tr>
     <tr>
         <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
     </tr>
     <tr>
         <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
     </tr>
     <tr>
         <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
     </tr>
     <tr>
         <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
          <td><input type="checkbox" /></td>
     </tr>
</table>
</div>

And then the Javascript (jQuery + jQuery UI):

$("#checkboxes").selectable( {filter: "input:checkbox",
            stop: function(event, ui) {

                $(".ui-selected").each( function(){

                    $(this).each( function(){
                        var val = $(this).attr("checked") ? null : "checked";
                        $(this).attr("checked", val);
                    });

                });
}});

You can check out a live demo at http://jsfiddle.net/whMyQ/3/

As always, questions and comments are welcome!

See you next year,
Setfive

With in-line FBML deprecated, the only way to accomplish this without using a third party branded solution is to create a Facebook iframe app. Here are the steps you need to take to get something up using PHP and the Facebook PHP SDK.

1. Create a new Facebook Application at https://developers.facebook.com/apps

2. Configure your new Facebook App the enable “Website” and “Page Tab”. You’ll need to enter a valid URL for the following fields:

• Site URL
• Page Tab URL
• Secure Page Tab URL

You’ll also want to use a HTTPs URL since Facebook sessions default to HTTPs by default and your iframe will be marked insecure if its over vanilla HTTP. For this walk through, lets assume were using https://www.setfive.com/fb/index.php? as the URL.

3. Now, you’ll want to add your new App to a Facebook Page. The easiest way to do this is to use this URL https://www.facebook.com/dialog/pagetab?app_id=YOUR_APP_ID&next=YOUR_URL replacing YOUR_APP_ID and YOUR_URL with your App ID and then a URL that is derived from your endpoint (or even just your endpoint). When you load that URL, you’ll be prompted to add your app to a page – select the page you want and submit the form.

4. The final piece is throwing together the actual PHP script. You’ll need the Facebook PHP SDK available on GitHub – https://github.com/facebook/php-sdk. Clone that and then this is the PHP script you’ll need:

<?php
require 'php-sdk/src/facebook.php';

$facebook = new Facebook(array(
  'appId'  => 'YOUR_APP_ID',
  'secret' => 'YOUR_APP_SECRET',
));

$req = $facebook->getSignedRequest();
?>

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"xmlns:fb="http://ogp.me/ns/fb#">

<head>
    <meta charset="utf-8" />
    <title></title>
</head>

<body>

<?php if( $req["page"]["liked"] ): ?>

	Content for users that have LIKED the page.

<?php else: ?>

	Content for users that HAVE NOT LIKED the page.

<?php endif; ?>

</body>

</html>

And thats it! Now you’ll be able to gate content from non-fans while growing the fanbase of your Facebook Page.

Drop any questions in the comments.

Recently I was working on a project where we upload backups to Amazon S3.  I wanted to keep the files around for a certain duration and remove any files that were older than a month.  We use the s3cmd utility for most of our command line based calls to S3, however it doesn’t have a built in “delete any file in this bucket that is older than 30 days” function.  After googling around a bit, we found some python based scripts, however there wasn’t any that was a simple bash script that would do what I was looking for.  I whipped this one up real quick, it may not be the best looking but it gets the job done:

#!/bin/bash

# Usage: ./deleteOld "bucketname" "30 days"

s3cmd ls s3://$1 | while read -r line;
  do
    createDate=`echo $line|awk {'print $1" "$2'}`
    createDate=`date -d"$createDate" +%s`
    olderThan=`date -d"-$2" +%s`
    if [[ $createDate -lt $olderThan ]]
      then
        fileName=`echo $line|awk {'print $4'}`
        echo $fileName
        if [[ $fileName != "" ]]
          then
            s3cmd del "$fileName"
        fi
    fi
  done;

Anyway, not to difficult to represent with a data structure but the complexity was going to be in tying the UI to the data structure with callbacks and events. Usually, I would of used a single $(“a”).click() handler to handle all the edit, delete, and configuration clicks in the UI but that quickly devolves into a disastrous mess of if statements and hasClass() checks.

Hoping to avoid this, I started thinking about cleaner ways to implement this and realized if I actually bound events to the individual objects they were going to effect the resulting code would be much cleaner. The UI elements were going to be dynamically generated each time the data structure was updated anyway so binding $.click() events on the <a> tags to their corresponding objects wouldn’t be to much extra work.

All in all, things worked out pretty well. The final code is much easier to follow and there isn’t a gigantic if() block which is impossible to trace.

I can’t share the actual implementation I used but I threw together an example which outlines the technique. Check out the JSFiddle at http://jsfiddle.net/fN46q/4/

Looking at the code, the Board object is an Array that in turn contains Piece objects to form a 3×3 grid.

The Piece objects individually supply a render function to display themselves and then contain a click() function which handles their $.click() events.

The key line which makes this work is:

   $(td).find("a").bind("click", {piece: this[i][j]}, this[i][j].click);

What the second parameter does is add the object into the Event object that is passed to the event handler. More info is available on the $.bind() documentation but looking at the click() function in the Piece object you can see where it comes in to play:

 click: function( e ){
    e.data.piece.val = !e.data.piece.val;
    e.data.piece.board.render();
    return false;
 }

So effectively, the data structure is now linked to the DOM.

As always, thoughts, comments and are feedback welcome!

Technically, 500Pearlstreet.com is running Drupal 7 with a couple of of pretty neat modules:

• The theme is a standard sub-theme of the excellent Omega responsive theme. The amount of configuration possible through the Omega UI is really impressive and a welcome change from how difficult theming was in Drupal 6.
• In-context links and images are being automatically powered by Zemanta which is pretty neat.
• OpenCalais is also running in the background providing semantic tagging capabilities. These aren’t exposed yet but hopefully will become useful when there is more content.

Anyway, it should be a good read so drop it into your readers!

Good luck finishing 2011 in style!