I currently have this WEB API running locally:
// POST api/CsvParse
[HttpPut]
public void Put([FromBody]string value)
{
if (string.IsNullOrEmpty(value))
throw new Exception("Input is null or empty.");
}
I currently have it running locally, and am sending a string to the put using POSTMAN. I have selected the body tab, and have the string pasted into the raw body tab:
It states that my text is unsupported, or when I add a break point the value is null or I get the error describing the format is incorrect.
What am I doing wrong?
Change the media type to x-www-form-urlencoded rather than multipart/form-data.
Also, WebAPI is particular about FromBody parameters. http://encosia.com/using-jquery-to-post-frombody-parameters-to-web-api/
For you, I think this is the relevant part:
- [FromBody] parameters must be encoded as =value
The final hurdle remaining is that Web API requires you to pass [FromBody] parameters in a particular format. That's the reason why our value parameter was null in the previous example even after we decorated the method's parameter with [FromBody].
Instead of the fairly standard key=value encoding that most client- and server-side frameworks expect, Web API's model binder expects to find the [FromBody] values in the POST body without a key name at all. In other words, instead of key=value, it's looking for =value.
This part is, by far, the most confusing part of sending primitive types into a Web API POST method. Not too bad once you understand it, but terribly unintuitive and not discoverable.
That's because there is no media type formatter that can serialize a raw string into your model (your route parameter with [FromBody]
attribute).
A quick and dirty workaround is to directly read the body of your request as a string:
[HttpPut]
public async Task<HttpResponseMessage> Put(HttpRequestMessage request)
{
var myCsv = await request.Content.ReadAsStringAsync();
// do stuff with your string
return new HttpResponseMessage(HttpStatusCode.OK);
}
As an alternative you could implement a custom media type formatter yourself, as per this answer .
There is a similar Q&A here
I found that solution #1 worked for me as I was trying to PUT JSON containing the Key/Value pair. So originally my JSON looked like this
{
"subscriber": {
"Id": "2",
"subscriptions":[
{
"Name": "Subscription 1",
"Id": "18",
"IsSubscribed": false
},
{
"Name": "Subscription 2",
"Id": "19",
"IsSubscribed": false
},
{
"Name": "Subscription 3",
"Id": "20",
"IsSubscribed": false
}
]
}
}
But I modified it to become
{
"Id": "2",
"subscriptions":[
{
"Name": "Subscription 1",
"Id": "18",
"IsSubscribed": false
},
{
"Name": "Subscription 2",
"Id": "19",
"IsSubscribed": false
},
{
"Name": "Subscription 3",
"Id": "20",
"IsSubscribed": false
}
]
}
And that worked. My PUT request from Postman was recognised in my C# web api using [FromBody]
Just to add my bit, there is one more solution to pass primitives into a POST or a PUT method. Just specify the model as JObject
. ASP.Net core web api then binds incoming JSON object(containing primitives like string) into JObject model object.
Your code would look like this:
// POST api/CsvParse
[HttpPut]
public void Put([FromBody]JObject value)
{
//access your string data
string data = value[SPECIFY_KEY_HERE];
if (string.IsNullOrEmpty(data))
throw new Exception("Input is null or empty.");
}
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