dougsparling.org (kl93)

Wednesday, March 12, 2008

Installing Ruby without openssl

When installing Ruby on an old machine, I got this error:


ruby make[1]: *** [ossl_ssl.o] Error 1

Other than installing openssl, which wasn't option, install ruby without openssl:


$ ./configure prefix=/home/doug/bin/ruby --without-openssl

Monday, March 10, 2008

Javascript - insertAfter(), formatCurrency, DOM Scripting

insertAfter()


function insertAfter(newElement,targetElement) {
    var parent = targetElement.parentNode;
    if (parent.lastChild == targetElement) {
        parent.appendChild(newElement);
    } else {
        parent.insertBefore(newElement,targetElement.nextSibling);
    }
}

formatCurrency()


function formatCurrency(amount) {
    var i = parseFloat(amount);
    if(isNaN(i)) { i = 0.00; }
    var minus = '';
    if(i < 0) { minus = '-'; }
    i = Math.abs(i);
    i = parseInt((i + .005) * 100);
    i = i / 100;
    s = new String(i);
    if(s.indexOf('.') < 0) { s += '.00'; }
    if(s.indexOf('.') == (s.length - 2)) { s += '0'; }
    s = minus + s;
    return s;
}

DOM scripting - create text node with value of  


var textEl = document.createTextNode('\u00a0');

Accordion Effects with Scriptaculous

I had a couple recent projects that required an accordion effect. I normally use jQuery, but found a couple nice Prototype/Scriptaculous accordions (one is for a Rails project, so we're already using Scriptaculous).

stickman labs
grf-design

Note - The stickman labs accordion doesn't appear to work with the latest Prototype (1.6.1). I'm using the combined js file from the stickman site.

Wednesday, February 27, 2008

jQuery Sortable with Ajax, PHP, and MySQL

I needed to create a sortable list that would save the order position of data items. I've been using jQuery more and more and decided to go with the Interface Elements for jQuery.

I found a blog entry titled jQuery Sortable Ajax PHP Integration that was a good start. However, it didn't actually use MySQL to store the sorted data so I've gone ahead and added the database queries and updates.

First I created a simple table to store links (I'd like my client to order the links they enter through an admin interface).


CREATE TABLE links ( 
id int(10) NOT NULL auto_increment, 
link_url varchar(50) NOT NULL, 
link_text varchar(50) NOT NULL, 
order_position int(2), 
primary key(id) 
);

Next is the PHP page that reads the link data from the table and displays the links based on the order_position column of the table.

index.php


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
                    "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script type="text/javascript" src="/js/jquery/jquery-1.2.3.min.js"></script>
<script type="text/javascript" src="interface.js"></script>
  
<script>
$(document).ready(
  function() {
    $("#sortme").Sortable({
      accept : 'sortitem',
      onchange : function (sorted) {
        serial = $.SortSerialize('sortme');

        $.ajax({
                  url: "sortdata.php",
                  type: "POST",
                  data: serial.hash,
                  // complete: function(){},
                  //success: function(feedback){ $('#data').html(feedback); }
                  // error: function(){}
        });
      }
    });
  }
);

  </script>
</head>
<body>

<ul id="sortme">
<?php
  // Connect to the database as necessary
  $dbh = mysql_connect('127.0.0.1','username','password')
    or die ("Unaable to connnect to MySQL");

  $selected = mysql_select_db("sort_test",$dbh)
    or die("Could not select sort_test");

  $result = mysql_query('SELECT * FROM links ORDER BY order_position');
  while ($row = mysql_fetch_array($result)) {
    print '<li id="' . $row{'id'} . '" class="sortitem">' . $row{'link_text'} . "\n";
  }
  mysql_close($dbh);
?>
</ul>
 
</body>
</html>

This will make an Ajax call back to the server where PHP will update the database as you drag and sort the list data:

sortdata.php


<?php

$sortme = $_POST['sortme'];
// Connect to the database as necessary
$dbh = mysql_connect('127.0.0.1','username','password')
  or die ("Unaable to connnect to MySQL");

$selected = mysql_select_db("sort_test",$dbh)
  or die("Could not select sort_test");

for ($i = 0; $i < count($sortme); $i++) {
  mysql_query("UPDATE links SET order_position=$i WHERE id=$sortme[$i]");
}
mysql_close($dbh);
?>

A little CSS certainly wouldn't hurt things. Here's some I found on another tutorial:


<style>
ul {
  list-style: none;
}
li {
  background: #727EA3;
  color: #FFF;
  width: 100px;
  margin: 5px;
  font-size: 10px;
  font-family: Arial;
  padding: 3px;
}
</style>

I wouldn't call this production ready code, but all the pieces are in place if you'd like to use jQuery with Ajax, PHP, and MySQL for a sortable list. Don't forget, you'll need to get jQuery itself and the interface.js file as well. Another thing to consider is alerting the user if the update fails or takes a long time.

Thursday, February 21, 2008

Ruby on Rails - Testing with Multiple Databases

I ran into errors when running tests for a Rails app using multiple databases. When testing, fixtures are automatically inserted into the primary database, and I was getting an error on an unused default fixture that was created when I built the model tied to the second database. Removing that fixture got my tests to pass...

More info here:

http://www.elctech.com/2007/3/8/using-and-testing-rails-with-multiple-databases
http://www.elctech.com/2007/5/30/using-and-testing-multiple-databases-in-rails-part-2

and on multiple databases in general:

http://wiki.rubyonrails.org/rails/pages/HowtoUseMultipleDatabases
http://wiki.rubyonrails.org/rails/pages/HowtoUseMultipleDatabasesWithFixtures

Tuesday, February 19, 2008

jQuery

I've been using the jQuery Javascript library a lot lately and it's definitely become my favorite library. (I've written four plugins in the last couple months to boot)

Here are a few links to useful jQuery resources.

jQuery: The Write Less, Do More, JavaScript Library
jQuery UI: Widgets, Components, and Interaction
Plugins - jQuery JavaScript Library
jQuery Blog
Learning jQuery
Visual jQuery
IBM developerWorks: Simplify Ajax development with jQuery

composite_primary_keys.gem

Ruby on Rails does not support composite primary keys and a legacy database I'm working with has lots of them...after a quick search I found this useful Gem:

composite_primary_keys.