append conditional html file output with xml response

Question

hey guys i have a restful xml service where client passes current version of html they are viewing. if the version on the server is the same as the client, i just respond with the current server version in xml. example: <Response ServerHTMLVersion="1" />

however if server html version is greater than current client version, i still spit out the same response like above like <Response ServerHTMLVersion="2" />. but problem being my client application needs to do a seperate http request to download the html file incase response xml version is greater than clients version

for performance reasons, i wanted to cut down this http request and i wanted to know what is the best way to do this. should i simply encode the html to make it xml safe and append that with xml response - problem with this being html is FAT and encoding makes it even fatter

OR

is there a better way of managing this? note that i am already gziping my response for both, xml as well as html right now

i wanted to know the way to do this keeping performance in mind. the restful xml service is implemented via asp.net 3.5 and iis 7

Answer 1

Have you thought about using HTTP headers? Since really the primary data here is the HTML, and the ServerHTMLVersion is a sort of "meta data" about that html, it should work.

Personally, I'd make the response to the request 1) blank when the versions match and 2) the HTML for non-matching versions; then, use the Pragma HTTP header to send something like Pragma: "ServerHTMLVersion=2". By doing this, you can easily check if the client and server versions differ, and just grab the full response if they're different.

Some people would debate the idea of returning HTML from a REST service, but I personally would consider this totally valid, and an nice clean way of separating your meta data from the actual user data.

-Jerod