Yesterday I wrote a post about the gateway that connects Fargo with WordPress.

In that post, I suggested that it is possible to replace that gateway, which does not handle unicode characters, with one that does. It is possible, and for a reasonably skilled server programmer, not even very much work. In this post I want to outline the problem, at a technical level.

The gateway

• It sits between Fargo and WordPress.

• Fargo is a JavaScript app running in the browser.

• We call the gateway with the jQuery routine $.ajax.

• In our gateway, we call WordPress through the MetaWeblog API, though a new gateway could use a different API, as long as it maintains the same interface to Fargo.

The parameters we send with the request are

• postTitle: the title of the post.

• postBody: the body of the post.

• idPost: the ID of the post, 0 if it's a new post.

• weblogUrl: the URL of the WordPress blog.

• blogUsername: the user's username.

• blogPassword: the user's password.

What the server does

• First, it gets the calling conventions for the blog using Really Simple Discovery to turn weblogUrl into an API address and a blog ID. It caches this result so subsequent calls won't have to go through the full RSD process.

• Then it makes a MetaWeblog API call to the WordPress server. Which call it makes depends on whether idPost is zero or non-zero. If it's non-zero it makes a metaWeblog.editPost call, if it's 0, it makes a metaWeblog.newPost call.

What the server returns

• In all cases it returns a JSONP call, to a routine called getData, with a single param, a JSON struct, that contains several fields.

  • link: points to the blog post.

  • idpost: the WordPress ID for the post, used in subsequent calls to identify the post.

  • error: its presence indicates that the call did not work. Its value is an error string that can be displayed for the user explaining the error.

• The content type of the response is application/json.

Access-Control-Allow-Origin header

• Very important: the gateway must set the Access-Control-Allow-Origin header to fargo.io, so the browser will let Fargo call your service.

Source code

• I'll provide source code for both the $.ajax call from Fargo and the gateway (written in UserTalk running in Frontier) as example-ware.

Business

• I wrote the gateway in January in a couple of days. It took that long because I was unfamiliar with the way the $.ajax process works. It might still take a couple of days to get it up and running and tested and well-enough debugged so users can depend on it. It's the kind of code that takes two or three sessions to complete.

• To deploy, it will have to be on a publicly-accessible server. On Amazon or Rackspace that server would cost less than $100 a month to run.

• One server could easily support the Fargo community, even with a fair amount of growth. WordPress is at this time a fairly small application for Fargo. Of course if it worked better it might be a larger application.

• Doc Searls contacted me today, a Fargo user, who runs a WordPress blog, and he has an interest in making this work, and has offered (I think) to help coordinate.

• I would love to see this as a community development thing. I will show people how to configure Fargo to talk with a different server. We can make it a preference, to make it as easy as possible.