Update list item Rest API: fixed the content-type value

[mahajangaurav]

The content-type for the Update list item REST API was incorrect in the documentation example here. This PR fixes the example

Category

• Content fix

Related issues

• fixes Incorrect value for the content-type for Update list item #6636

What's in this Pull Request?

Updated the content-type header value in the example to the correct value: "application/json;odata=verbose", instead of: "application/json", which does not work.

[VesaJuvonen]

Docs Build status updates of commit 5a5ed8b:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/sp-add-ins/working-with-lists-and-list-items-with-rest.md	✅Succeeded	View

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[andrewconnell]

I'm not sure this fix is correct... can you confirm this with an example? The content-type header has nothing to do with the metadata returned in the ODATA spec... it only defines what data is being SENT to the service.

[mahajangaurav]

Hi @andrewconnell

I understand what you are saying about the content-type header but the API returns a 400 if odata=verbose is not sent as part of the header. The error message returned is '__metadata does not exist on type 'SP.Data.DataItem'

The rest API seems to be expecting that value in the header

Jerry has also provided an example here in the original issue: #6636 (comment)

Other similar API calls expect this value for the content-type header as well, such as Create List Item, Delete List Item and a few others.

This is just a guess but from what I am reading this could have been done to support the Verbose JSON format in the OData 3.0 spec. More about this here (you are likely already familiar but just in case):
Verbose JSON Format:
https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-odata/c91c88d1-b477-46ed-bfa1-210b22ecf9ca
https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-odata/d91277b3-30dc-4195-9848-20f2f95c9ecf

Odata 3.0 spec discussing the json verbose format: https://www.odata.org/documentation/odata-version-3-0/json-verbose-format/

Based on what I read, it may have been done to support sending the __metadata as part of the request? FWIW, I tried with odata=minimalmetadata and that resulted in the same error.

Thanks!

[mahajangaurav]

@andrewconnell - just making sure you were able to review my earlier response. Please let me know if I can further assist in any other way. Thank you!

[andrewconnell]

I haven't looked at it... I help with triaging the issues & managing PR's, but only the quick stuff. Things that need more research, I do that in my spare time and been swamped lately. Can't make a commitment when I'll get back to this thread, or when MSFT will pick it up.