Rails, QBOE, qbXML and integrating them all together - ruby-on-rails

Question

I am currently developing a Ruby/Rails app that will be used in-house as a sort of Enterprise application to support our business.
Our company uses Quickbooks Online to do almost all of our accounting, most importantly for invoicing.
I am looking for a way to automatically generate invoices from our Rails app into Quickbooks, as well as be able to pull customer balances and some other "basic" information into the Rails app to display on a customer information screen.
I have done a lot of research on the topic, and have yet to find an acceptable solution to what we're trying to accomplish.
Quickbooks Web Connector - Not applicable since are not running Quickbooks Pro
Intuit Anywhere app - The app we are using is certainly not a SaaS App, as it is specifically designed for our business, and the only Quickbooks file/account it will ever see is our own
Quickbooks Online/qbXML Gateway application - This seems to be the best fit
So I have spent considerable time with Keith Palmer's Consolibytes wiki, and Intuit's Official Documentation (which is great to get started, but doesn't really provide much help for the details), and have been unable to even link my application to quickbooks using the https://qbo.intuit.com/redir/addsdkapp?appid=YOUR-ID-HERE&appreferer=&appdata=1 link.
My server does have a GoDaddy generated SSL certificate, and I have visited the connection callback URL and have confirmed that everything is in working order there. However, I keep getting a "Failed to notify third party application about this connection" error. There is no evidence of a request from QB to my server in any of my logs.
So what I'm getting at here is this:
Is what I'm trying to do possible and/or practical?
Am I going the right way about it?
I'd really love to find someone out there who has done something like this before and maybe shed some light on the whole process.
Thanks!

Answer 1

So what I'm getting at here is this: Is what I'm trying to do possible and/or practical?
Yes.
Am I going the right way about it?
Almost. :-)
From what you posted:
My server does have a GoDaddy generated SSL certificate, and I have visited the connection callback URL and have confirmed that everything is in working order there.
It sounds like you registered in HOSTED mode.
Unfortunately, the Intuit servers don't consider GoDaddy certificates valid, and thus won't be able to HTTP POST your connection ticket to those servers. That's why you're seeing this:
Failed to notify third party application about this connection
Additionally, I believe they do reverse DNS checks, which will most likely fail because GoDaddy generally doesn't set up rDNS entries.
The solution is:
Do not register in HOSTED mode
Instead, register in DESKTOP mode.
Once you've registered, use this URL to register get your connection ticket:
https://login.quickbooks.com/j/qbn/sdkapp/confirm?appid=YOUR-APPLICATION-ID-HERE&serviceid=2004&appdata=1
(make sure to plug your actual application ID into the URL)
Instead of Intuit HTTP POSTing the connection ticket to you, the connection ticket will be displayed and you can copy/paste it. From there on in, it's as simple as HTTP POSTing additional HTTP requests to Intuit's servers.
Sample XML requests can be found on our QuickBooks integration wiki - make sure you use the DESKTOP mode examples.
Hope that helps clear things up!