Add Version to GeoObject and add ability to get latest version to API

[craigappl]

We anticipate the need to support versioning of GeoObjects as they change over time.

A version is a numeric sequence that is auto generated each time a particular GeoObject is updated.

When we add support for version to a GeoObject, we need to add the ability to get a particular version and the "latest" version from the CGR API. This could be done by adding a version parameter to the endpoint with version=N signifying a particular sequence or version=latest identifying the latest version and returning it to the host.

[nmceachen]

I created a ticket on our end to add the sequence number. There are different ways we can go about this.

Increment on the individual object
Whenever an object is modified, its integer sequence number would be incremented by one. This would allow the RESTful API to support a method that allows and object to be fetched by a given sequence number.

It is currently not in the HGLC spec to store multiple versions of a GeoObject other than in the Pending and Active status.

Is there a need by Reveal to be able to fetch multiple versions of an object beyond Pending and Active?

Increment on all objects
Currently the back end of GeoPrism supports using a sequence number that is incremented for all objects. It allows for the ability to query all objects that are greater than a given sequence number. We could use this as an additional parameter for the methods to the CGR.

I would imagine you would also want to query for objects that have been modified after a given date.

[justinlewis]

A version property was added to the adapter as of v0.3.0.

An API endpoint for getting a GeoObject by a specific version is not completed yet.