//Quelltext nach dem Buch:
//Professionelle Websites
//von Stefan Münz
//ISBN 3-8273-2218-9
var default_order     = "desc"; // "asc" || "desc"
var asc_img_uri       = "dl_script/asc.gif";
var desc_img_uri      = "dl_script/desc.gif";
var asc_img_alt_text  = "▼";
var desc_img_alt_text = "▲";

var tables = new Array();
var ti = 0;

function sort_table(id) {
  this.id = id;
  this.obj;
  this.tbody_obj;
  this.sort_cols = 0;
  this.sort_rows = 0;
  this.img_ids = new Array();
  this.tr_ids = new Array();
  this.td_ids = new Array();
  this.active_sort_col;
  this.active_sort_order = default_order;
}

function init_tabsort(table_id) {
  if(!document.getElementById) {
    return;
  }
  tables[ti] = new sort_table(table_id);
  var t = ti;
  ti += 1;
  tables[t].obj = document.getElementById(table_id);
  for(var i = 0; i < tables[t].obj.childNodes.length; i++) {
    switch(tables[t].obj.childNodes[i].nodeName.toLowerCase()) {
      case 'colgroup':
        for(j = 0; j < tables[t].obj.childNodes[i].childNodes.length; j++) {
          if(tables[t].obj.childNodes[i].childNodes[j].nodeName.toLowerCase() == 'col') {
            tables[t].sort_cols += 1;
          }
        }
        break;
      case 'tbody':
        tables[t].tbody_obj = tables[t].obj.childNodes[i];
        break;
      default:
        break;
    }
  }
  var tri = 0;
  var tdi = 0;
  for(i = 0; i < tables[t].tbody_obj.childNodes.length; i++) {
    if(tables[t].tbody_obj.childNodes[i].nodeName.toLowerCase() == 'tr') {
      tables[t].tbody_obj.childNodes[i].id = 'tr_' + tri;
      tables[t].tr_ids.push('tr_' + tri);
      tables[t].sort_rows += 1;
      tdi = 0;
      for(j = 0; j < tables[t].tbody_obj.childNodes[i].childNodes.length; j++) {
        if(tables[t].tbody_obj.childNodes[i].childNodes[j].nodeName.toLowerCase() == 'td') {
          tables[t].tbody_obj.childNodes[i].childNodes[j].id = 'tr_' + tri + '_td_' + tdi;
          tables[t].td_ids.push('tr_' + tri + '_td_' + tdi);
          tdi += 1;
        }
      }
      tri += 1;
    }
  }
}

function get_sort_table_obj_by_id(id) {
  for(var i = 0; i < tables.length; i++) {
    if(tables[i].id == id) {
      return(tables[i]);
    }
  }
}

function numsort(a,b) {
  return parseFloat(a) - parseFloat(b);
}

function tabsort(table_id, sort_type, col_n) {
  if(!document.getElementById) {
    return;
  }
  var delimiter = "|||||";
  var to = get_sort_table_obj_by_id(table_id);
  var sort_array = new Array();
  for(var i = 0; i < to.sort_rows; i++) {
    tr_array = new Array();
    tr_id = 'tr_' + i;
    td_id = tr_id + '_td_' + col_n;
    tr_array.push(document.getElementById(td_id).innerHTML);
    for(var j = 0; j < to.sort_cols; j++) {
      if(j == col_n) {
        continue;
      } else {
        tr_id = 'tr_' + i;
        td_id = tr_id + '_td_' + j;
        tr_array.push (document.getElementById(td_id).innerHTML);
      }
    }
    tr_str = tr_array.join(delimiter);
    sort_array.push(tr_str);
  }
  if(sort_type == 'an') {
    sort_array.sort();
  }else if(sort_type == 'n') {
    sort_array.sort(numsort);
  }
  if(to.active_sort_order == 'desc') {
    sort_array.reverse();
    to.active_sort_order = 'asc';
  } else {
    to.active_sort_order = 'desc';
  }
  for(i = 0; i < sort_array.length; i++) {
    tr_array = sort_array[i].split(delimiter);
    first = tr_array.shift();
    tr_array.splice(col_n, 0, first);
    for(j = 0; j < to.sort_cols; j++) {
      tr_id = 'tr_' + i;
      td_id = tr_id + '_td_' + j;
      document.getElementById(td_id).innerHTML = tr_array[j];
    }
  }
  var img_html;
  if(to.active_sort_order == 'asc') {
    img_html = '<img src="' + desc_img_uri + '" height="15" width="15" alt="' + desc_img_alt_text + '">';
  } else {
    img_html = '<img src="' + asc_img_uri + '" height="15" width="15" alt="' + asc_img_alt_text + '">';
  }
  for(i = 0; i < to.sort_cols; i++) {
    if(i == col_n) {
      document.getElementById(table_id + '_sort_img_' + i).innerHTML = img_html + " ";
    } else {
      document.getElementById(table_id + '_sort_img_' + i).innerHTML = " ";
    }
  }
}