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PHP脚本调用Yahoo! Search API实现搜索的效果，全部脚本如下：
<?php
// Yahoo Web Services PHP Example Code
// Rasmus Lerdorf
// www.knowsky.com
$appid = "YahooDemo";
// 在这输入你申请的ID号
$service = array("image"=>"http://api.search.yahoo.com/ImageSearchService/V1/imageSearch",
"local"=>"http://api.local.yahoo.com/LocalSearchService/V1/localSearch",
"news"=>"http://api.search.yahoo.com/NewsSearchService/V1/newsSearch",
"video"=>"http://api.search.yahoo.com/VideoSearchService/V1/videoSearch",
"web"=>"http://api.search.yahoo.com/WebSearchService/V1/webSearch");
?>
<html>
<head><title>PHP Yahoo Web Service Example Code</title></head>
<body>
<form action="YahooSearchExample.php" method="GET">
Search Term: <input type="text" name="query" /><br />
Zip Code: <input type="text" name="zip" /> (for local search)<br />
<input type="submit" value=" Go! " />
<select name="type">
<?php foreach($service as $name => $val) {
if(!empty($_REQUEST["type"]) && $name == $_REQUEST["type"])
echo "<option SELECTED>$name</option>";
else echo "<option>$name</option>";
} ?>
</select>
</form>
<?php
function done() {?>
</body></html>
<?php
exit;
}
if(empty($_REQUEST["query"]) || !in_array($_REQUEST["type"],array_keys($service))) done();
// Ok, here we go, we have the query and the type of search is valid
// First build the query
$q = "?query=".rawurlencode($_REQUEST["query"]);
if(!empty($_REQUEST["zip"])) $q.="&zip=".$_REQUEST["zip"];
if(!empty($_REQUEST["start"])) $q.="&start=".$_REQUEST["start"];
$q .= "&appid=$appid";
// Then send it to the appropriate service
$xml = file_get_contents($service[$_REQUEST["type"]].$q);
// Parse the XML and check it for errors
if (!$dom = domxml_open_mem($xml,DOMXML_LOAD_PARSING,$error)) {
echo "XML parse error";
foreach ($error as $errorline) {
/* For production use this should obviously be logged to a file instead */
echo $errorline["errormessage"]."<br />";
echo " Node : " . $errorline["nodename"] . "<br />";
echo " Line : " . $errorline["line"] . "<br />";
echo " Column : " . $errorline["col"] . "<br />";
}
done();
}
// Now traverse the DOM with this function
// It is basically a generic parser that turns limited XML into a PHP array
// with only a couple of hardcoded tags which are common across all the
// result xml from the web services
function xml_to_result($dom) {
$root = $dom->document_element();
$res["totalResultsAvailable"] = $root->get_attribute("totalResultsAvailable");
$res["totalResultsReturned"] = $root->get_attribute("totalResultsReturned");
$res["firstResultPosition"] = $root->get_attribute("firstResultPosition");
$node = $root->first_child();
$i = 0;
while($node) {
switch($node->tagname) {
case "Result":
$subnode = $node->first_child();
while($subnode) {
$subnodes = $subnode->child_nodes();
if(!empty($subnodes)) foreach($subnodes as $k=>$n) {
if(empty($n->tagname)) $res[$i][$subnode->tagname] = trim($n->get_content());
else $res[$i][$subnode->tagname][$n->tagname]=trim($n->get_content());
}
$subnode = $subnode->next_sibling();
}
break;
default:
$res[$node->tagname] = trim($node->get_content());
$i--;
break;
}
$i++;
$node = $node->next_sibling();
}
return $res;
}
$res = xml_to_result($dom);
// Ok, now that we have the results in an easy to use format,
// display them. It"s quite ugly because I am using a single
// display loop to display every type and I don"t really understand HTML
$first = $res["firstResultPosition"];
$last = $first + $res["totalResultsReturned"]-1;
echo "<p>Matched ${res[totalResultsAvailable]}, showing $first to $last</p>";
if(!empty($res["ResultSetMapUrl"])) {
echo "<p>Result Set Map: <a href="${res[ResultSetMapUrl]}">${res[ResultSetMapUrl]}</a></p>";
}
for($i=0; $i<$res["totalResultsReturned"]; $i++) {
foreach($res[$i] as $key=>$value) {
switch($key) {
case "Thumbnail":
echo "<img src="${value[Url]}" height="${value[Height]}" width="${value[Width]}" />";
break;
case "Cache":
echo "Cache: <a href="${value[Url]}">${value[Url]}</a> [${value[Size]}]<br />";
break;
case "PublishDate":
echo "<b>$key:</b> ".strftime("%X %x",$value);
break;
default:
if(stristr($key,"url")) echo "<a href="$value">$value</a><br />";
else echo "<b>$key:</b> $value<br />";
break;
}
}
echo "<hr />";
}
// Create Previous/Next Page links
if($start > 1)
echo "<a href="/YahooSearchExample.php".
"?query=".rawurlencode($_REQUEST["query"]).
"&zip=".rawurlencode($_REQUEST["zip"]).
"&type=".rawurlencode($_REQUEST["type"]).
"&start=".($start-10).""><-Previous Page</a> ";
if($last < $res["totalResultsAvailable"])
echo "<a href="/YahooSearchExample.php".
"?query=".rawurlencode($_REQUEST["query"]).
"&zip=".rawurlencode($_REQUEST["zip"]).
"&type=".rawurlencode($_REQUEST["type"]).
"&start=".($last+1)."">Next Page-></a>";
done();
?>
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.knowsky.com/yahoo/
