Inbound web service that can both create and update incidents?

[peterraeves]

We are creating an Inbound Web Service that can do 3 things. Create, update and close an Incident. What would best practice be here? Should I create 3 services? Should I create a single Service with 3 transform maps? Should I create a single service with a single TM that covers all situations?

I thought about all situations but all of them had bad points to them. So I thought I'd turn to you guys who are much smarter than me.

1. 3 Services & 3 Transform Maps

+: Easier for the external customer, as the name of the service is clear and they will receive only a single result

-: Double work for field maps/values that are the same for all services

2. 1 Service & 3 Transform Maps

+: Single interface, so customer does not need to worry about what to call

+: Only need maps for those fields that are needed for the current service

-: The external customer will receive the results of 3 TMs

-: All TMs need onBefore maps to check whether they should run

-: Double work for field maps/values that are the same for all services

3. 1 Service & 1 Transform Map

+: Everything is centralized

-: Cannot use coalesce field 'number', because it will not be present when creating a new ticket. This will cause the TM to fail.

PS: As a bonus question, where should I put default values. For example, for the contact_type field, I'd like to enter 'Automated Event', which is not the overal default. Where would I put this assignment? Field Map? Transform Script?

[peterraeves]

That's what I did with the number field. The problem is that when your payload does not contain the number field, it will complain. I would have expected it to do an insert at that time, but it complains for the missing coalesce field and skips the record all together. I would prefer to have a service that can be called without the coalesce field and still work, because it would not be very clean to tell the customer to add 'number:' on an insert...

[Mike Allen · Accepted solution]

If you check 'Coalesce Empty Field' it'll stop complaining.   That's what we do and it has worked for 2 years now.   If you don't have a coalesce field, how is it going to know what to update?   Even with Table API, you have to pass something to tell it what to update.

[peterraeves]

In the case there is no coalesce field, it should create a new record.

In the case there is a coalesce field in the payload, it should update the record corresponding the given INC number.

(If the coalesce field contains an invalid INC number, it should reject)

[Mike Allen]

That is what Import Set APIs do:

Import Set API - ServiceNow Wiki

Except maybe the third point.   You may have to script that.  

[peterraeves]

No they do not

Even when I enter 'u_number:' in the body, it still complains. It expects some value. I guess I'll just have to use a workaround, which is a Field Map script on sys id. That worked in the past.