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Thinking about Discovery
for blogging to quickly develop tools and services that can serve and con-
sume an OpenSearch query and response. Like SRU, OpenSearch utilizes
an easy-to-understand query syntax that can be expressed through a URL.
Probably OpenSearch’s greatest strength is the ease with which the
protocol can be implemented. Utilizing a minimalist approach, OpenSearch
uses a minimal number of arguments for query. Couple this with the known
RSS/Atom response format, and most systems can be retrofitted to support
OpenSearch queries and responses in the course of a couple of hours. For
example, at Ohio State University, the local digital collections system has
been created using the Samvera technology stack. The URL to create a query
into the digital collections system is fairly straightforward:
• baseURL: https://library.osu.edu/dc/catalog
• encoding: utf8=%E2%9C%93
• Query string: q=test
• Reurn format: format=json
Using this structure, any request made to the digital collections system will
return back JSON results. Since JSON is a format that is easily parseable by
most web-based programming languages, implementing an OpenSearch
data feed is relatively easy. What’s more, by providing an OpenSearch feed
and creating the necessary autodiscovery link, for example (see figure 9.7),
<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01//EN” “http://www.w3.org/TR/html4/strict.dtd”>
<html xmlns=”http://www.w3.org/1999/xhtml” xml:lang=”en” lang=”en” dir=”ltr”>
<head profile=”http://a9.com/-/spec/opensearch/1.1/”>
<link rel=”search”
type=”application/opensearchdescription+xml”
href=”http://linktoyourcontentsearch.xml”
title=”Your content search” />
</head>
<body>
<!--- ... --->
</body>
</html>
FIGURE 9.7
OpenSearch Autodiscovery Link Syntax
a user’s web browser would be able to automatically recognize the search
profile and make it accessible directly within the application.
Implementing the OpenSearch protocol proved to be simpler than
initially expected in part due to the protocol’s minimalist specifications
(www.opensearch.org/Specifications/OpenSearch/1.1) and the wide variety
of example code that is currently available and shows OpenSearch’s integra-
tion within other applications. In all, the process took about ten minutes to
produce the following plug-in:
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