{"id":1926,"date":"2012-01-17T09:12:18","date_gmt":"2012-01-17T00:12:18","guid":{"rendered":"https:\/\/regex.info\/blog\/2012-01-17\/1926"},"modified":"2012-01-17T09:12:18","modified_gmt":"2012-01-17T00:12:18","slug":"lightroom-plugin-development-adding-a-url-handler-to-a-lightroom-plugin","status":"publish","type":"post","link":"https:\/\/regex.info\/blog\/2012-01-17\/1926","title":{"rendered":"Lightroom Plugin Development: Adding a URL Handler to a Lightroom Plugin"},"content":{"rendered":"\n\n\n
\nNOTE<\/b>: Images with an icon next to them have been artificially shrunk to better fit your screen; click the icon to restore them, in place, to their regular size.\n<\/div>\n\n\n

This post is of interest only to Lightroom plugin developers.<\/p>\n\n

Round about Lightroom 3.2,<\/span> Adobe added support for intercepting\n“lightroom:\/\/<\/b>” URLs, but have not documented it yet, so I'll do so\nhere. It's particularly<\/span> useful as part of an OAuth-authentication\nprocedure.<\/p>\n\n

What<\/b><\/p>\n\n

You can have your plugin automatically respond to certain\n“lightroom:\/\/<\/b>” URLs if they are formatted correctly, and if you\nadd appropriate support to your plugin.<\/p>\n\n

URL Form<\/b><\/p>\n\n

After registering the appropriate handler in you plugin, as described below, the handler will\nbe invoked when your system browser receives a URL<\/span> of the form:<\/p>\n\n

\n lightroom:\/\/<\/b>your.plugin.id<\/i>\n<\/div>\n\n

The “your.plugin.id<\/i>” is the LrToolkitIdentifier<\/b> in Info.lua<\/b>. For example, the id\nfor my Flickr plugin<\/a> is\n“info.regex.lightroom.export.flickr2<\/b>”, so it can be set to handle URLs such as:<\/p>\n\n

\nlightroom:\/\/info.regex.lightroom.export.flickr2\/blah-blah-blah\nlightroom:\/\/info.regex.lightroom.export.flickr2?this=blah&that=blah\nlightroom:\/\/info.regex.lightroom.export.flickr2#foobar\n<\/div>\n\n

etc.<\/p>\n\n

How<\/b><\/p>\n\n

Create a .lua<\/b> file that returns a table<\/span> along the lines:<\/p>\n

\nreturn {\n   URLHandler = function(url)\n       -- The url string sometimes actually have a double quote as<\/i>\n       -- the first and last byte, so strip just in case.<\/i>\n       url = url:gsub('^\"(.*)\"$', \"%1\")\n\n       -- Work with url here...<\/i><\/pre>
.\n.\n.\n.\n.\n<\/div>
   end\n}\n<\/pre>\n\n
Wrapping the function in a one-element table seems like an odd level of indirection, but that's how it works.<\/p>\n\n
You then add a reference to that file in your Info.lua<\/b>, as “URLHandler<\/b>”. If the file<\/span> is named “MyUrlHandler.lua<\/i>”, for example,\nthe reference in Info.lua<\/b> would look like:<\/p>\n\n