Problems using aoColumns dynamically with defined column array

Hello everyone!

The idea is that I want to use autodetectable sorting on my datatables which work good, but in cases where I have textboxes, checkbox or other, I use sSortDataType, and it seems to work also! But! I'm having some problems with aoColumns when using an array, dynamically defined on every subsite. When I go into a subsite I start with defining the columns attached like this:

 
ths.each( function( index ) {
   th = $(this);
   if( th.attr('sorting') ) {
       var column = '{ "sSortDataType": "' + th.attr('sorting') + '" }';
   } else {
       var column = "null";
   }
   aoColumn.push(column);
}

dom-text is then defined in the header of where I have textboxes columns. All "null" are handled with auto-type detection.

A console.log of "aoColumn" gives for example:
{ "sSortDataType": "dom-text" }, null, null, null, { "sSortDataType": "dom-text" }, null

I want to do it like this, by insert the array to aoColumns, but it doesn't work!:

 
var options = {
            "aLengthMenu": [[10, 50, 100, -1], [10, 50, 100, "All"]],
            "aoColumns": aoColumn,
            .... 
    };

but if I hardcode my array from one subsite into the aoColumns like this it works!!!;

 
var options = {
            "aLengthMenu": [[10, 50, 100, -1], [10, 50, 100, "All"]],
            "aoColumns": [
                       { "sSortDataType": "dom-text" }, 
                       null, 
                       null, 
                       null, 
                       { "sSortDataType": "dom-text" }, 
                       null
             ],
            ....        
    };

It works very nicely even if I write new text into textbox, they are sorted good. But only in the hardcoded example. How can I get my dynamic array to work? Any idea? If you need more code or explaination, please tell me.

Thanks,
Ole