+ ##
+ # Set allowed request formats if no explicit format has been
+ # requested via a URL suffix. Allowed formats are taken from
+ # any HTTP Accept header with XML as the default.
+ def set_request_formats
+ unless params[:format]
+ accept_header = request.headers["HTTP_ACCEPT"]
+
+ if accept_header
+ # Some clients (such asJOSM) send Accept headers which cannot be
+ # parse by Rails, for example:
+ #
+ # Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
+ #
+ # where both "*" and ".2" as a quality do not adhere to the syntax
+ # described in RFC 7231, section 5.3.1, etc.
+ #
+ # As a workaround, and for back compatibility, default to XML format.
+ mimetypes = begin
+ Mime::Type.parse(accept_header)
+ rescue Mime::Type::InvalidMimeType
+ Array(Mime[:xml])
+ end
+
+ # Allow XML and JSON formats, and treat an all formats wildcard
+ # as XML for backwards compatibility - all other formats are discarded
+ # which will result in a 406 Not Acceptable response being sent
+ formats = mimetypes.map do |mime|
+ if mime.symbol == :xml || mime == "*/*" then :xml
+ elsif mime.symbol == :json then :json
+ end
+ end
+ else
+ # Default to XML if no accept header was sent - this includes
+ # the unit tests which don't set one by default
+ formats = Array(:xml)
+ end
+
+ request.formats = formats.compact
+ end