实现原理:
在页面加载完成时获取页面来源(document.referrer),并分析搜索引擎关键词,然后获取页面上所有元素,递归查询是否含有搜索关键字,如果有,就创建一个 span 元素,并应用关键词样式,替换原有节点。
<script>
var allCount=0;
function highlightWord(node,word,realUrl) {
// Iterate into this nodes childNodes
if (node.hasChildNodes&&allCount<4) {
var hi_cn;
for (hi_cn=0;hi_cn<node.childNodes.length;hi_cn++) {
highlightWord(node.childNodes[hi_cn],word,realUrl);
}
}
// And do this node itself
if (node.nodeType == 3) { // text node
tempNodeVal = node.nodeValue.toLowerCase();
tempWordVal = word.toLowerCase();
if (tempNodeVal.indexOf(tempWordVal) != -1&&allCount<4) {
pn = node.parentNode;
if (pn.className != "searchword") {
// word has not already been highlighted!
nv = node.nodeValue;
ni = tempNodeVal.indexOf(tempWordVal);
// Create a load of replacement nodes
before = document.createTextNode(nv.substr(0,ni));
docWordVal = nv.substr(ni,word.length);
after = document.createTextNode(nv.substr(ni+word.length));
hiwordtext = document.createTextNode(docWordVal);
hiword = document.createElement("a");
hiword.className = "searchword";
hiword.setAttribute("href",realUrl);
hiword.appendChild(hiwordtext);
pn.insertBefore(before,node);
pn.insertBefore(hiword,node);
pn.insertBefore(after,node);
pn.removeChild(node);
allCount++;
}
}
}
}
function googleSearchHighlight() {
if (!document.createElement) return;
ref = document.referrer;
if (ref.indexOf('?') == -1) return;
qs = ref.substr(ref.indexOf('?')+1);
qsa = qs.split('&');
for (i=0;i<qsa.length;i++) {
qsip = qsa[i].split('=');
if (qsip.length == 1) continue;
if (qsip[0] == 'q' || qsip[0] == 'p') { // q= for Google, p= for Yahoo
words = unescape(decodeURIComponent(qsip[1].replace(/\+/g,' '))).split(/\s+/);
for (w=0;w<words.length;w++) {
highlightWord(document.getElementsByTagName("body")[0],words[w]);
}
}
}
}
function testAddlink() {
var wordList = new Array("用户","命令");
var linkList=new Array("http://www.116tea.cn","http://www.iteye.com","http://www.163.com");
for (w=0;w<wordList.length;w++) {
allCount=0;
highlightWord(document.getElementsByTagName("body")[0],wordList[w],linkList[w]);
}
}
window.onload = testAddlink;
</script></html>