Inside Model.php

/**
     * Allows all columns on the current database table to be sorted through
     * query scope
     * 
     * @param type $query
     * @param type $field
     * @param type $sort
     * @return object
     */
    public function scopeSort($query, $field = NULL, $sort = NULL){
        
        /*
         * Make sure both the field and sort variables are present
         */
        if($field && $sort){
            /*
             * Retrieve all column names for the current model table
             */
            $columns = Schema::getColumnListing($this->table);

            /*
             * Make sure the field inputted is available on the current table
             */
            if(in_array($field, $columns)){

                /*
                 * Make sure the sort input is equal to asc or desc
                 */
                if($sort === 'asc' || $sort === 'desc'){
                    /*
                     * Return the query sorted
                     */
                    return $query->orderBy($field, $sort);
                }
            }
        } else{
            /*
             * Default order by created at field
             */
            return $query->orderBy('created_at', 'desc');
        }

Link helper.php

 $field = Input::get('field');
            $sort = Input::get('sort');
            
            if($sort == 'desc'){
                $parameters['sort'] = 'asc';
            } else{
                $parameters['sort'] = 'desc';
            }
            
            if($field == $parameters['field']){
                $icon = sprintf('fa %s-%s', $icon, $parameters['sort']);
            } else{
                $icon = sprintf('fa %s', $icon);
            }
            
            return sprintf('<a href="%s">%s <i class="%s"></i></a>', route($name, $parameters), $title, $icon);}

can you explain more ? how to implement in > L5 .. thanks..