Looking for an API for Google Images, I was surprised to find there isn't one. I discovered a project in ASP.NET from a few years ago which shows how difficult life can be if your language doesn't play well with XML.
A few lines of XQuery gets a sub-set of the thumbnails for a given search :
declare function local:google-images(
$search as xs:string,
$start as xs:integer,
$n as xs:integer) as element(a)* {
let $response := httpclient:get(
xs:anyURI(
concat("http://images.google.com/images?q=", encode-for-uri($search),
"&start=",$start)
) ,false(), ()
)
return
if ($response/@statusCode eq "200")
then ($response/httpclient:body//h2[@class="hd"]/following-sibling::div[1]//a)
[position() <= $n]
else ()
}
);
This function hides the construction of the search url and the parsing of the HTML page. The eXist function httpclient:get tidies the HTML so it is well-formed. Inspection of the HTML allows construction of a suitable XPath expression to scrape the thumbnail code out of the page.
The function can then be used in a script, like this one to get a random image from the first 50 results
declare option exist:serialize "method=xhtml media-type=text/html";
...
(: get a random thumbnail :)
let $q:= request:get-parameter ("q","")
let $start := util:random(50)
let $thumbnail := local:google-images($q,$start,1)
return
$thumbnail/img