Bearer Token Authorizations and JPATH Expressions

 Yeah, apples and oranges.  And I am not going to relate the two either.  They are just the flotsam and jetsam floating about in my mind from recent development.

Bearer token authorization comes out of the OAuth 2.0 standard, but has taken on a life of its own and become a commonly used authorization mechanism for REST services.

In the Rocket UniData UniBasic Extensions Version 8.2.2 you can find details on the Authorization setting required in setRequestHeader.  There is a whole intro page about OAuth 2.0 and U2.  

Short version:

setRequestHeader(HTTPRequest.Handle,"Authorization", "Bearer ":BEARER.TOKEN)

setRequestHeader(HTTPRequest.Handle,"Authorization", "DIRECT ":HMAC.TOKEN)

And these have to be done after the Request object is created.  There is no option in setHTTPDefault to specify the authorization type ahead of time. 

So in the REST.SERVICES table you just need to start the Auth Token prompt with "Bearer " or "DIRECT " and then the token, and REST.SERVICE will setRequestHeader and your REST.SERVICE request will be off to the races.

JSONPath or JPATH is for JSON what XPATH is for XML; a standard for declaratively specifying pieces of a JSON string to be returned.  I stumbled into the need for such a thing while working on the REST provider for NEWS.ARTICLES.  If you want to provide the capability to an article author to layout an HTML div and specify replacements from a REST service then you need some standard declarative expression to say "put THAT piece from the REST service results HERE!". And it would be nice to make the replacement expressions familiar and consistent with some larger standard.

The REST.NEWS news provider subroutine simply calls out to JPATH to extract out the pertinent data.

 *

2110* Replace dictionary references with values

 *     

     VAR.CNT = COUNT(LINE, "&")/2

     FOR VAR.IDX = 1 TO VAR.CNT

        VAR.IDX = VAR.IDX ;* Audits!

        VAR.NAME = FIELD(LINE, "&", 2, 1)

        TARGET.NAME = VAR.NAME

        TARGET.VALUE =  JPATH(udoRESTData, TARGET.NAME )

JPATH is not yet a W3C standard.  There is an IETF working group developing a standards-track JSONPath specification based on work by Stefan Goessnerwhich.  So while not set in stone there is general consensus on what a JPATH expression ought to look like and how it ought to function.

There are no JPATH features in the Rocket UDO functionality currently. However, the primitives are there for building a JPATH function.  And that is what I have started. It is available as a patch to Manage 2000 8.1 sp5.  And I would lead with "not complete yet".  But it provides the basic functionality which allows expressions in NEWS.ARTICLES like "&$.Customers[1].OutputEmailAddresses.SaleseQuoteEmail&" and since "$" is optional and array slice filter defaults we can write more concisely &Customers.OutputEmailAddresses.SalesQuoteEmail&.  

Why "not complete yet"?  Well it will do basic array slicing expressions, but a lot of work remains to implement all the possible filter expression and array slices within array slices and so forth.