Summarized considerations for Workflows extension

[jerstlouis]

This is a summary of issues submitted in response to the request for public comments, to be considered to ensure the possibility to define a Workflows extension, as being investigated in the Modular OGC API Workflows project.

These 3 issues have been filed separately:

• mimeType vs. mediaType: For execution schema 'format', use 'mediaType' rather than 'mimeType' #87
• support uom and format in both ref and inline: OpenAPI literalData only String, inlineValue/referenceValue cannot specify uom / format; Merge complexData and literalData? #95
• add a list input type: Consider a list input type to accept a list of inputs identified by their own IDs #105

In #47 (comment) ), the following general changes have also been suggested:

• Inside an input, drop the "input" : { "value" : { part, and directly have e.g. href next to the id. Other properties currently going under input or value (e.g. format when needed) would go at the same level as that.
• Rename inlineValue to simply value. When using value, numbers can be directly as numeric values, not strings (e.g. "value" : 0.05) -- it was confirmed that this is already possible.

In addition, to support the new proposed type of inputs identifying an OGC API collection (or a process generating one), a process description document would require an additional mechanism to specify that a particular input is expected to be a collection (and potentially support a particular API such as Features or Coverages). This could potentially be covered in the Workflows extension itself, but we should ensure that there is a mechanism to extend the process descriptoin document to make this possible.

Other additions and relaxed rules for the process execution schema are also being proposed specifically for the Workflows extension.

A draft OpenAPI definition and prototype server for the Modular OGC API Workflows extension is available at:

https://app.swaggerhub.com/apis/jerstlouis/MOAW/MOAW-0.2

and draft specifications available at:

https://github.com/jerstlouis/wps-rest-binding/tree/master/extensions/workflows

in hope of eventual inclusion in the official OGC API - Processes repository (see also PR #99).