New GraphQL APIs - things to fix

[t2gran]

Here is a list of things we should fix in the future version of the Transmodel API

General

• Consider wrapping arrays in response to be extendable
• Return general Shape, not specific types like Polygon
• Design for "limiting" queries (>10Mb seen in travel search) See Harden web server securety #5037
• Paging, connections and nodes
• Framework support for sorting/filtering on lists

Routing request

• Support for multi access/egress modes requests (today OTP2 only support explicit modes)
• Consider using minTransferTime, not transferSlack like OTP1. board-/alightSlack should be tuning parameters?
• Support of maxNumTransfers like OTP1. This is a pareto criteria; Hence is algorithmically ok to use. The current Raptor aditionalNumTransfers is difficult to understand and communicate - should be removed.
• Global IDs (Apollo-caching). EstimatedCall.id

Types

• Duration Consider using ISO-8601 format PnDTnHnMn

Dated Service Journey (DSJ)

• Replace ServiceJourney in Trip(Leg) with DSJ

Bike Rental

• Bike rental station coordinates should NOT be optional
• Available number of bikes can be unknown (null)
• Differentiate between stations and free-floating bicycles
• Add GBFS form factors

Legs

• Make separate types for the various legs: walking leg, transit leg, rental leg, car hailing leg, transfer leg, ...

Places

• Quay.stopPlace can NOT be null. Enforce none null for all child to parent relations.
• Should we list modes/submodes for patterns visiting, not using the station/stop fields?
• Make separate types for Stations and Stops
  • Make Stop an interface since there are a number of implementations: RegularStop, AreaStop, GroupStop...

Real time

• Better support for missing references from Alert to entities
• Alerts on legs

Filter design

Something like

input SelectPattern {
 mode : Mode
 subMode : String
 agency : ID
 route : ID
 trip : ID
 not : SelectPattern
 and : [SelectPattern!]
 or : [SelectPattern!]
}

Example:

list(
  select : {
    mode : BUS
    and: [
      { subMode : "localBus" }
      {
        or: [
          { agency : "XYZ" }
          { agency : "ABC" }
    ] } ]
    not: { route: "B12" }
  }
) { ... }

References

1. Production Ready Graphql by Marc-Andre Giroux.
2. https://medium.com/workflowgen/graphql-query-timeout-and-complexity-management-fab4d7315d8d