How to apply FB registration with our custom registration process

JFBConnect lets you get a lot of different information about the user from their Facebook profile. The list of fields that are available from Facebook can be found at the URL below:
developers.facebook.com/docs/graph-api/reference/v2.1/user
JFBConnect supports almost all the fields listed on that page. One thing to note is that Facebook (and most other social networks) do not provide the user's phone number.

So, during normal registration using JFBConnect, you'd be able to import the user's information but would need to ask them for their phone number as their username.

To answer your questions:

1. what data is available from FB which we can map to our additional user fields, and is it possible to get those information automatically mapped by your extension

Yes, you can import the info from Facebook above as mentioned. However, we don't have a profile plugin for Fabrikar. We support Joomla's built in profile plugin, JomSocial, EasySocial, K2, Kunena and a few others, with more on the way.

We also have a "Custom Database" plugin where you can select a specific database table to import data into. That may work with Fabrikar's tables, depending on how they are formatted (1 row per user with the columns as the profile fields), but I don't know that off hand.

2. if not, do you provide plugin events at which we would be able to intercept and create / modify the user based on our need and to which you supply the FB data?

The best would be to create your own Profile Plugin to import the data. A small plugin to just import data is about 30 lines of new code to setup which field can be imported into and how to save the data.

Alternatively, we have an easy profile class you can use to make API calls to the social network and grab the user's data to use however you want.

3. if so, can you point me to your documentation for this or provide me a snippet where this takes place?

Creating your own Profile Plugin . That doc should get you going. Using an already created plugin from our package will also make things much simpler to understand.

4. i do understand that we are going to have issues with our username policy (we require it to be the mobile number) as not all users have their mobile number tied to their FB account. But the question is in those cases users have those numbers tied to their FB account, is it the case that we can get it along with other FB user data in the plugin event?

No, phone number is not available from Facebook at all. That's a restriction from them. You can get phone number from LinkedIn and VK, I believe.

5. as part of the registration process, is it possible to ask the registering user some additional questions such as mobile number (if that is not possible to get another way)

Yup. If you're using the JFBConnect registration flow, you can show additional fields by setting up your Profile Plugin properly.

6. the pilot went on a bit longer and we already have amassed over 11000 users registered and is wondering how we would deal with those users in order to tie their account with their resp. FB account?

There are easy ways for a user to connect their existing Joomla account to a Facebook account. They can do that after they login to your site and click Facebook to make the connection or you can configure JFBConnect to automatically link users that are connecting by their email address. So, if they login with Facebook and their FB email address is already associated to a Joomla user, that connection will be made automatically.

7. given your understanding of our situation and your experience what would you say is best practice approach in order for us to provide a seamless user experience, because we truly wouldn't want to loose our precious users right at the gate by having the slightest of complication

JFBConnect is meant to work with existing sites by providing multiple ways to let users login with their social networking account and connect it to an existing account. Since you'll need to use a form-based registration, our "Registration" page also includes a "Login" section where a user can login to an existing account *or* choose to register a new account.

The biggest obstacle you'll encounter is the Fabrik integration, which we can help with.

I hope that helps explain, but if you have any other questions, let me know.

Thanks,
Alex