POST to WebAPI from a SharePoint Workflow

  • Article

There seems to be a good amount of information on consuming RESTful services in SharePoint workflow, but there are limited articles on POST. In this article I will show you how to POST a complex object to WebAPI. I say “complex” but it is really just a data class, WebAPI only wants one parameter on POST so that parameter better be good! I am just going to jump into the steps and will explain after so you can get going.

Step 1: Have a WebAPI. If you do not I have one you can use the zipped up at the bottom of this article.

Step 2: Create your workflow

Step 3: Create “Header” dictionary with the below fields (make sure Authorization is blank!)

Item

Type

Value

Comments

Accept

String

application/json;odata=verbose

 

content-type

String

application/json;odata=verbose

 

Authorization

String

 

This has to be set to empty string to force auth.

 

 

 Step 4: Create “Data” Dictionary

Item

Type

Value

Comments

Action

String

Whatever you want to log

 

ID

String

Current Item:ID

 

User

String

Current Item:Modified By

Currently using email address. Domain user will not encode in JSON correctly.

               

 

Step 4: Create HTTP Web Service Call and use the following settings:

Address: https://YOURSERVER/api/Demo

RequestHeaders: Header

RequestContent: Data

RequestType: HTTP POST

  

Step 5: Done! Data will post to your WebAPI and you can save it to SQL or send it to your grandmother via email!

  

OK, that was easy, but let’s dig in a little. Here are some thoughts/notes on this whole process:

  • Most issues with the POST are authorization related. Setting the header “Authorization” to empty string forces the system to perform authentication or it will try anonymous (which will fail miserably).

  • Workflow will handle a moderately complex object, it does not like arrays. This is about as complex as it should get: {"Action":"Some Action", "ID":"10", "User":"Dan Biscup"}

  • Under the covers it is encoding as JSON, claims user names have \\ in there and it will break.

  • WebAPI likes 1 parameter in the POST, so use a complex object, I usually keep these in a separate dll/project that we can use in other projects.

  • I like to keep a "GetAll" method that just returns the controller name so I can make sure it is running in IIS like /api/demo.

DemoWebAPI.zip