/**
 * Cette classe javascript gère les processus des filtres de recherche
**/

var Filters = {

    // le select qui va être modifié
    obj : '' ,
    
    get_sector_categories : function(sector_id, action) {
        
        if (action == null) {
            action = '/process.php' ;
        }
        
        Filters.obj = 'categories_options' ;
        params = 'command=get_sector_categories&sector='+sector_id ;
        vAjax.send_request('post', action, params, true, Filters.onreadystatechange) ;
        
        // on reset les métiers lorsqu'on change le secteur
        if (obj = getById('trades_options')) {
            obj.innerHTML = "" ;
        }
     },
    
    get_category_trades  : function(categ_id, action) {
        
        if (action == null) {
            action = '/process.php' ;
        }
        
        Filters.obj = 'trades_options' ;
        params = 'command=get_category_trades&sector='+categ_id ;
        vAjax.send_request('post', action, 'command=get_category_trades&category='+categ_id, true, Filters.onreadystatechange) ;
    },
    
    onreadystatechange : function() {
        /**
            0 Uninitialized
                The initial value.
            1 Open
                The open() method has been successfully called.
            2 Sent
                The UA successfully completed the request, but 
                no data has yet been received.
            3 Receiving
                Immediately before receiving the message body (if any). 
                All HTTP headers have been received.
            4 Loaded
                The data transfer has been completed.
        **/
        
        //obj = getById() ;
        
        switch (vAjax.xhReq.readyState)  {
            case 1:
                //obj.innerHTML = 'Chargement en cours...' ;
                break ;
                
            case 4:
                
                // transformation du XML en une collection d'éléments HTML
                values = vAjax.xhReq.responseXML.getElementsByTagName("option") ;

                select = getById(Filters.obj) ;

                while (select.length)   {
                    select.remove(0) ;
                }
    
                var opt;
                for (var i = 0; i < values.length; i++) {
                    opt = document.createElement("option");
                    select.appendChild(opt);
                    opt.value = values[i].getAttribute('value') ;
                    opt.text = values[i].childNodes[0].nodeValue ;
                }

                vAjax.busy = false ;
                break ;
        }
        
    }
} ;