Is it possible to convert an existing website application into a Facebook app?

I looked at a few of the SO questions that were similar to mine but didn't find them as informative as I had hoped. I read one place that said use iFrame but that requires using the Canvas, and Facebook api, and finally, now on Oct. 1, SSL (which means a static IP, more money, paid certificate.)

I don't want all that for a sandbox. I want to build, test, and if I think the product is worthy, then, after I am satisfied with my product, get all the stuff required for a Facebook app. If I take a low price host, I can do it chea开发者_如何学Pythonply for my "sandbox."

Not sure how to proceed.

edit: For that matter, I can do it all locally before putting on FB.

The quickest & easiest way to get started with integrating with Facebook is to add a "Login with Facebook" button to your site: Facebook for Websites. Users will browse to your site at your domain as usual, as opposed to inside a Facebook canvas. You'll have access to any Facebook feature you want to test to see if a canvas app is worthwhile.

This does require that you set up a Facebook Developer app to get an App ID and Secret, but you won't have to parse a signed_request, use SSL, etc.

Once you do this, a user can click the "Login with Facebook" button on your site and allow access on the permissions prompt. That user will then be authenticated with your Facebook app, and you'll have access to the social channels like feeds and requests, the Graph API, etc.

Update

To answer @johnny's comment question: Yes, by using the Facebook Javascript SDK. You can post to a user's wall by either prompting them with a Feed Dialog each time you want them to post a story to their wall, or by requesting the 'publish_stream' extended permission, which allows you to post stories to their wall without prompting the user every time (only if the user indicates they want to share that particular story - be sure to read through the TOS).