I'm trying to add a custom field to my community's lightning-based self-registration form.

I've created a Contact field set and named it: SelfRegistration
The contact field I'd like to add is a custom field called: Company_Name

In the community builder there seems to be a place where I can indicate the API name for this field set to add it to the registration form, but I'm unable to figure out the proper syntax/format. Any guidance would be greatly appreciated.



Things to note:
If its easier to add it onto the User record instead of the Contact record that should be find four our use case.
Eventually we would like to add a Job Title text field as well. 

I'm trying to add a custom field to my community's lightning-based self-registration form.

I've created a Contact field set and named it: SelfRegistration
The contact field I'd like to add is a custom field called: Company_Name

In the community builder there seems to be a place where I can indicate the API name for this field set to add it to the registration form, but I'm unable to figure out the proper syntax/format. Any guidance would be greatly appreciated.



Things to note:
If its easier to add it onto the User record instead of the Contact record that should be find four our use case.
Eventually we would like to add a Job Title text field as well. 

During the sites self-registration process, I have only come across the ability to create a portal user that creates both a contact and a user synchronously.  I would like to be able to create a portal user using an existing contact.  I tried setting the contact id on the user object before I called createPortalUser, but it still created a new contact.  We are trying to eliminate the possibility of duplicate contacts.

Hello everyone.  I was wondering if it was possible to edit xml files within salesforce using visualforce, javascript, triggers, or anything?  I'm using a javascript s-control and I need to pull the values from salesforce objects into an xml file to get it to work properly.  I have tried creating a visualforce page with the type set to "text/xml" with test data, and for some reason this is not working at all. It works if I upload the test .xml file as an attachment on the object, but I cannot figure out how to modify the file dynamically.  Any help would be appreciated, thanks!