JavaScript DOM编程艺术-第八章

第八章

案例代码：

function displayAbb() {

if (!document.getElementsByTagName || !document.createElement

  || !document.createTextNode)return false;

  var abbr =document.getElementsByTagName('abbr');

  var defs =new Array()

for (var i =0; i < abbr.length; i++){

if (abbr[i].childNodes.length <1)continue;

    var title = abbr[i].getAttribute('title');

    var text = abbr[i].lastChild.nodeValue;

    defs[text] = title;

  }

var dlElement =document.createElement('dl');

  for (textin defs){

var title = defs[text];

    var dtElement =document.createElement('dt');

    var dtText =document.createTextNode(text);

    dtElement.appendChild(dtText);

    var ddElement =document.createElement('dd');

    var ddtext =document.createTextNode(title);

    ddElement.appendChild(ddtext);

    dlElement.appendChild(dtElement);

    dlElement.appendChild(ddElement);

  }

if (dlElement.childNodes.length <1)return false;

  //创建标题

  var header =document.createElement('h2');

  var header_text =document.createTextNode('Abbreviations');

  header.appendChild(header_text);

  //把标题添加到页面主体

  document.body.appendChild(header);

  //把定义列表添加到页面主体

  document.body.appendChild(dlElement);

}

function displayCitations() {

var blockQ =document.getElementsByTagName('blockquote');

  for (var i =0; i < blockQ.length; i++){

if (!blockQ[i].getAttribute('cite'))continue;

    var cit = blockQ[i].getAttribute('cite');

    var quoteElement = blockQ[i].getElementsByTagName('*');

    if (quoteElement.length <1)continue;

    var elem = quoteElement[quoteElement.length -1];

    var links =document.createElement('a');

    var links_text =document.createTextNode('source');

    links.appendChild(links_text);

    links.setAttribute('href',cit);

    links.setAttribute('target','_blank');

    var superscript =document.createElement('sup');

    superscript.appendChild(links);

    elem.appendChild(superscript);

  }

}

function displayAccesskeys() {

if (!document.getElementsByTagName || !document.createElement

    || !document.createTextNode)return false;

  var links =document.getElementsByTagName('a');

  var akeys =new Array();

  for (var i =0; i

var current_link = links[i];

    if (!current_link.getAttribute('accesskey'))continue;

    var key  = current_link.getAttribute('accesskey');

    var text = current_link.lastChild.nodeValue;

    akeys[key] = text;

  }

var list =document.createElement('ul');

  for (keyin akeys){

var text = akeys[key];

    var str = key +':' + text;

    var item =document.createElement('li');

    var item_text =document.createTextNode(str);

    item.appendChild(item_text);

    list.appendChild(item);

  }

var header =document.createElement('h3');

  var header_text =document.createTextNode('Accesskeys');

  header.appendChild(header_text);

  document.body.appendChild(header);

  document.body.appendChild(list);

}

addLoadEvent(displayCitations);

addLoadEvent(displayAccesskeys);

addLoadEvent(displayAbb);