AspNetCore WebApi ODataController Cannot Deserialize JSON Payload

Question

I am having an trouble getting my V4 ODataController to deserialize a JSON payload. I have created a sample project in github to illustrate my exact issue:

https://github.com/valainisgt/BadODataDeserialization

When the data submitted to the '/odata/models' endpoint using a content-type of application/json, the model is not populated. Using the exact same data keys and values but this time as application/x-www-form-urlencoded, the model is populated.

What am I missing here?

Edit:

Here is what my payload looks like:

{ 'ModelId': 0, 'Name': "John Doe" }

This is an asp.net core application targeting .NET 462.

As such I am using the Microsoft.AspNetCore.* packages.

Answer 1

When the data submitted to the '/odata/models' endpoint using a content-type of application/json, the model is not populated. Using the exact same data keys and values but this time as application/x-www-form-urlencoded, the model is populated.

1. If you would like to receive a content-type of application/json , you need to decorate your Model with a [FromBody]

   public IActionResult Post([FromBody]Model m)
   

Test case :

POST http://localhost:50317/odata/models HTTP/1.1
Content-Type: application/json

{
    ModelId:11,
    Name:"hello"
}

2. If you want to receive a content-type of x-www-form-urlencoded , you should add a [Bind()] :

   public IActionResult Post([Bind("ModelId,Name")]Model m)
   

Test Case :

POST http://localhost:50317/odata/models HTTP/1.1
Content-Type: application/x-www-form-urlencoded

ModelId=11&Name=hello

However , there's no built-in modelbinder that will bind both data types . If you do want to do that , consider the following approach :

1. write two action methods and route according to different headers
2. custom a modelbinder

For more information , refer docs here