电脑技术学习

利用Yahoo! Search API开发自已的搜索引擎-javascript版

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美国东部时间3月1日,雅虎公司联合创始人之一的杨致远将宣布公司的搜索网络将进入Web服务。雅虎公司在www.developer.yahoo.com网站建立了Yahoo Search Developer Network,公司计划在此纽约举行的搜索引擎战略大会(Search Engine Strategies Conference)上推出这一计划。该网络将允许开发者在雅虎搜索之上建立新的应用程序,其中包括图像、视频、新闻以及地区搜索等内容。想要使用这项服务的会员必须先去http://api.search.yahoo.com/webservices/register_application 申请一个自已的ID号,注:每个ID号每天只能搜索5000次。

下面我们看一下,如何用javascript脚本调用Yahoo! Search API实现搜索的效果,全部脚本如下:

/*
* yahoo_search_api.js
* Part of the Yahoo! Search Sidebar for Firefox
* powered by Yahoo! Search web services (http://api.search.yahoo.com)
* Written by Marc Abramowitz (http://marc.abramowitz.info)
* Copyright (C) 2005 Yahoo! Inc.
* www.mypchelp.cn
*/

function Yahoo_Search() {}

Yahoo_Search.baseURL = function () {
return "http://api.search.yahoo.com/WebSearchService/V1/";
}

Yahoo_Search.appid = function () {
return "YahooSearchSidebar";
}

Yahoo_Search.baseArgs = function () {
return "appid=" + this.appid();
}

Yahoo_Search.Results = function (args) {
var xmlUrl = this.baseURL() + "webSearch?"
+ this.baseArgs()
+ "&query=" + args["Doc"]
+ "&zip="
+ "&start=" + args["First"]
+ "&results=" + args["Count"];
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("GET", xmlUrl, false);
xmlhttp.send(null);
return this.readXML(xmlhttp.responseXML);
}

Yahoo_Search.readXML = function (xmlDoc) {
try {
var retVal = new Array();
var resultSet = xmlDoc.getElementsByTagName("ResultSet")[0];
var totalResultsAvailable = parseInt(resultSet.getAttribute("totalResultsAvailable"))
var totalResultsReturned = parseInt(resultSet.getAttribute("totalResultsReturned"));
var firstResultPosition = parseInt(resultSet.getAttribute("firstResultPosition"));
var start = firstResultPosition;
var end = firstResultPosition + totalResultsReturned - 1
var results = xmlDoc.getElementsByTagName("Result");
for (var i = 0; i < results.length; i++) {
var result = results[i]
var title = result.getElementsByTagName('Title')[0].firstChild.nodeValue;
var summary = '';
if (result.getElementsByTagName('Summary')[0].firstChild) {
summary = result.getElementsByTagName('Summary')[0].firstChild.nodeValue;
}
var clickUrl = result.getElementsByTagName('ClickUrl')[0].firstChild.nodeValue;
var url = result.getElementsByTagName('Url')[0].firstChild.nodeValue;
retVal[i] = { I: start + i, Title: title, Summary: summary, ClickUrl: clickUrl, Url: url };
}

return retVal;
} catch(exception) {
alert('Exception occurred while reading XML (i=' + i + '; start=' + start + ';end=' + end + '): ' + exception);
}
}


有兴趣的朋友还可以看一下由[动态网站制作指南]所制作的ASP版本:http://www.mypchelp.cn/yahoo/