Roll your own search engine plugins
In response to Willscrlt's comment here's a short guide to creating search plugins for Firefox.
The XML file (the plugin)
The plugin itself is an OpenSearch XML file. You can find details of the OpenSearch spec here. While I'd recommend reading the whole spec it's much easier to hack an existing plugin.
Start with the code from my Google Caffeine search plugin.
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/" xmlns:moz="http://www.mozilla.org/2006/browser/search/">
<ShortName>Google Caffeine</ShortName>
<Description>Google Caffeine Dev Preview Search</Description>
<Image width="16" height="16">data:image/png;base64,AAABAAEAEBAAAAEAGABoAwAAFgAAACgAAAAQAAAAIAAAAAEAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAADs9Pt8xetPtu9FsfFNtu%2BTzvb2%2B%2Fne4dFJeBw0egA%2FfAJAfAA8ewBBegAAAAD%2B%2FPtft98Mp%2BwWsfAVsvEbs%2FQeqvF8xO7%2F%2F%2F63yqkxdgM7gwE%2FggM%2BfQA%2BegBDeQDe7PIbotgQufcMufEPtfIPsvAbs%2FQvq%2Bfz%2Bf%2F%2B%2B%2FZKhR05hgBBhQI8hgBAgAI9ewD0%2B%2Fg3pswAtO8Cxf4Kw%2FsJvvYAqupKsNv%2B%2Fv7%2F%2FP5VkSU0iQA7jQA9hgBDgQU%2BfQH%2F%2Ff%2FQ6fM4sM4KsN8AteMCruIqqdbZ7PH8%2Fv%2Fg6Nc%2Fhg05kAA8jAM9iQI%2BhQA%2BgQDQu6b97uv%2F%2F%2F7V8Pqw3eiWz97q8%2Ff%2F%2F%2F%2F7%2FPptpkkqjQE4kwA7kAA5iwI8iAA8hQCOSSKdXjiyflbAkG7u2s%2F%2B%2F%2F39%2F%2F7r8utrqEYtjQE8lgA7kwA7kwA9jwA9igA9hACiWSekVRyeSgiYSBHx6N%2F%2B%2Fv7k7OFRmiYtlAA5lwI7lwI4lAA7kgI9jwE9iwI4iQCoVhWcTxCmb0K%2BooT8%2Fv%2F7%2F%2F%2FJ2r8fdwI1mwA3mQA3mgA8lAE8lAE4jwA9iwE%2BhwGfXifWvqz%2B%2Ff%2F58u%2Fev6Dt4tr%2B%2F%2F2ZuIUsggA7mgM6mAM3lgA5lgA6kQE%2FkwBChwHt4dv%2F%2F%2F728ei1bCi7VAC5XQ7kz7n%2F%2F%2F6bsZkgcB03lQA9lgM7kwA2iQktZToPK4r9%2F%2F%2F9%2F%2F%2FSqYK5UwDKZAS9WALIkFn%2B%2F%2F3%2F%2BP8oKccGGcIRJrERILYFEMwAAuEAAdX%2F%2Ff7%2F%2FP%2B%2BfDvGXQLIZgLEWgLOjlf7%2F%2F%2F%2F%2F%2F9QU90EAPQAAf8DAP0AAfMAAOUDAtr%2F%2F%2F%2F7%2B%2Fu2bCTIYwDPZgDBWQDSr4P%2F%2Fv%2F%2F%2FP5GRuABAPkAA%2FwBAfkDAPAAAesAAN%2F%2F%2B%2Fz%2F%2F%2F64g1C5VwDMYwK8Yg7y5tz8%2Fv%2FV1PYKDOcAAP0DAf4AAf0AAfYEAOwAAuAAAAD%2F%2FPvi28ymXyChTATRrIb8%2F%2F3v8fk6P8MAAdUCAvoAAP0CAP0AAfYAAO4AAACAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAQAA</Image>
<InputEncoding>UTF-8</InputEncoding>
<Url type="application/x-suggestions+json" rel="suggestions" method="GET" template="http://suggestqueries.google.com/complete/search?output=firefox&client=firefox&hl={moz:locale}&q={searchTerms}" />
<Url type="text/html" method="GET" template="http://www2.sandbox.google.com/search?q={searchTerms}"/>
</OpenSearchDescription>
Change the "ShortName" and "Description" to describe your search.
<Description>Twitter realtime search</Description>
The next line, "Image" can be either an image URI or base64 encoded image as text. Encoding the image as text is faster and more reliable but static. You can find base64 encoders online should you choose to encode as text. For this example I'll use a URL.
The "application/x-suggestions" URL line is optional. This line enables the suggest feature by sending the partial search string to a suggest API each time a new character is typed. Items in the curly braces {} are variables. The search provider must provide a suggest API in order to use this. If you are unsure whether the search provider has a suggest API delete this line.
The next URL line is the one that runs the actual search. It tells the browser to use the "GET" HTTP method at the specified URL and insert the search terms in place of the variable {searchTerms}.
This is what the new search plugin XML would look like:
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/" xmlns:moz="http://www.mozilla.org/2006/browser/search/">
<ShortName>Twitter</ShortName>
<Description>Twitter realtime search</Description>
<Image height="16" width="16" type="image/x-icon">http://twitter.com/favicon.ico</Image>
<InputEncoding>UTF-8</InputEncoding>
<Url type="text/html" method="GET" template="http://search.twitter.com/search?q={searchTerms}"/>
</OpenSearchDescription>
The installer
The installer is also part of the OpenSearch spec. It's a Javascript method 'window.external.AddSearchProvider()' on an HTML page which tells the browser that the linked XML file is a search engine plugin to be installed instead of rendered.
Add Twitter search
That's it.
About
Kyle is a geek from Hawaii living in Tokyo who enjoys writing scripts and hacking stuff as a hobby. He is a member of the Tokyo Linux User Group (TLUG) and advocates knowledge sharing through libre open source and creative commons.
Kyle also dabbles in photography though he has a better grasp of the processes involved in digitally recording photons than the artistic insight to produce expressive images.
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