CodeIgniter – GAS ORM

November 24th, 2011

CodeIgniter comes with an ActiveRecord implementation that is fairly straightforward. You can retrieve table rows easily, but you have to write your own logic if you need an extra layer of abstraction (models). Models can help for example to traverse relationships between entities easily, by lazy or eager-loading related entites when they are needed.

There are many PHP ORMs available that provide this abstraction, but none of them integrates nicely with CodeIgniter’s ActiveRecord. At least, I could find any.

I was looking for an ORM that:

  • is a layer on top of CodeIgniter’s ActiveRecord implementation. I don’t like importing a large 3th party library like Doctrine into my CodeIgniter projects, and trick CodeIgniter into using that instead of its own databases access layer.
  • Provides freedom in how and when to use it. I like the idea of convention over configuration, but in real world situations, using a framework that enforces too strict can be a burden. For example when using a legacy database.

Enter GAS ORM. Gas ORM is an excellent initiative by a single developer: Taufan Adity. GAS can be mixed with ActiveRecord calls, and supports convention as well as configuration. On top of that, the developer welcomes requests and questions. If you want to make handling database access with CodeIgniter easier: try it!

Gas code example:

$this->load->library('gas');
// to see available models :
// var_dump($this->gas->list_models());
$user = new User;

// Now you can use any available Gas method, or your User models public method

$user1 = $user->find(1);

$user1 = Gas::factory('user')->find(1);

I haven’t tested GAS extensively yet though, but the first version looks very promising.

Links

I’m developing a small console application in C# to convert .gde files – file format of the wonderful “The Guide outliner” – to .chm (Microsoft Compiled HTML Help).

First step is to convert a .gde file to XML. This can be done with gdeutil, a tool included with The Guide. However, gedeutil.exe does not create a valid XML files: the character ‘&’ in node titles is not escaped to ‘&’.

So, I had to incorporate an XML preprocessing step in my tool, in which unescaped charachters are replaced by their XML entities. Otherwise, the document can not be parsed by the .NET XML parser (or most other parsers).

This is the method I created for this purpose:

/// <summary>
/// Inserts '&amp;' for '&' character in XML text.
/// </summary>
/// <param name="xmlText"></param>
public static String PreProcess(String xmlText)
{
    if (String.IsNullOrEmpty(xmlText))
        return xmlText;
   
    bool ampersand = false;

    StringBuilder output = new StringBuilder();
    StringBuilder buffer = new StringBuilder();
    for (int i = 0; i < xmlText.Length; i++)
    {
        char c = xmlText[i];
        if (c == '&')
        {
            // Maybe this is the start of an entity
            ampersand = true;
            buffer.Append(c);
        }
        else if (ampersand && c >= 64 && c <= 122)
        {                                        
            buffer.Append(c);
        }
        else if (ampersand && c == ';')
        {
            // Turns out to be an entity; don't change the output                
            output.Append(buffer.ToString());
            buffer.Clear();
            output.Append(c);
            ampersand = false;
        }
        else if (ampersand && (c < 64 || c > 122))
        {
            // Turns out not to be an entity                                      
            output.Append("&amp;" + c);
            buffer.Clear();
            ampersand = false;
        }
        else
        {
            output.Append(c);
        }                
    }
    return output.ToString();
}

Note that this is not a way of escaping entities in a text string (thats what HttpUtility.HtmlEncode is for), but a method of escaping characters in a complete XML document that includes tags The trick is to ignore already escaped characters; otherwise a simple search ‘&’ and replace with ‘&amp;’ would suffice.

I’m aware that this is not a fail-safe method. Nevertheless, I’m confident that this method is robust enough for use with XML files produced by gdeutil

Links