Posting json through UnityWebRequest

Hi I am trying to get unity to work with my Node.js server.
But for some reason the request body returns my json string as

Code (JavaScript):

1. { '{"level":1,"timeElapsed":47.5,"playerName":"Dr Charles Francis"}': '' }

Seems like the whole string is interpreted as the first field of the json string.
So here i create the object and stringify it:

Code (CSharp):

1. MyClass myObject = new MyClass();
2. myObject.level = 1;
3. myObject.timeElapsed = 47.5f;
4. myObject.playerName = "Dr Charles Francis";
5. string jsonStringTrial = JsonUtility.ToJson(myObject);

next op i create the UnityWebRequest and post.

Code (CSharp):

1. UnityWebRequest www = UnityWebRequest.Post("http://localhost:3000/api/rawCoords", jsonStringTrial);
2. www.SetRequestHeader("Accept", "application/json");
3. yield return www.Send();

Do you guys have a better idead of passing this json string, am I doing something weird or is there a better way to do this?

 

Apparently 'Post' doesn't work with JSON - you need to use 'Put':

Code (CSharp):

1. UnityWebRequest www = UnityWebRequest.Put("http://localhost:3000/api/rawCoords", jsonStringTrial);
2. www.SetRequestHeader("Content-Type", "application/json");

p.s. More discussion here - the last post uses the newer Unity system and it appears to work ok with Post so might be worth looking at https://forum.unity3d.com/threads/unitywebrequest-post-url-jsondata-sending-broken-json.414708/

 

try this:

Code (CSharp):

1. IEnumerator Post(string url, string bodyJsonString)
2.     {
3.         var request = new UnityWebRequest(url, "POST");
4.         byte[] bodyRaw = Encoding.UTF8.GetBytes(bodyJsonString);
5.         request.uploadHandler = (UploadHandler) new UploadHandlerRaw(bodyRaw);
6.         request.downloadHandler = (DownloadHandler) new DownloadHandlerBuffer();
7.         request.SetRequestHeader("Content-Type", "application/json");
8.         yield return request.SendWebRequest();
9.         Debug.Log("Status Code: " + request.responseCode);
10.     }

found here:
https://forum.unity.com/threads/unitywebrequest-post-url-jsondata-sending-broken-json.414708/

 

Hello. Thank-you for this. This seems to have solved my problem. But can you please explain on why this works and why the standard POST example code given on Unity docs doesn't work. here: "https://docs.unity3d.com/ScriptRefe...002.912384649.1608363462-815429442.1596618243"

 

Just an FYI, this solution worked for me on 2021.1.12f1.

 

Thank you this worked very well for me

 

Thank you a lot, after searching for hours.

 

Every year, a thanks ;-)

 

This works like a Charm. Thanks

 

Awesome, Thanks!

 

Important! Don't forget to dispose the UnityWebRequest after sending the data. Just add

request.Dispose();

after

Debug.Log();

.

If you don't, you'll get a memory leak error saying that a native collection has not been disposed. Otherwise, this code works great!

 

For anyone wondering, the correct way would be

Code (CSharp):

1.  
2. using (UnityWebRequest www = UnityWebRequest.Post(uri, payload))
3.             {
4.                 //Your code here
5.             }

 

Thank you so much! I've spent hours trying to fix this.

 

One thing, I can't able to understand.
Why we enclose UnityWebRequest within Using construct?
Just for garbage collection purpose.
Already we are adding the code within IEnumerator.

 

Because it implements the

IDisposable

interface.

 

Right. The exact reason why a class may implement the IDisposable interface can vary. Though in most cases its because the class uses some native resources that should be released as soon as possible. This is usually the case for things like file handles, or network sockets. As it was mentioned above, most managed .NET classes which wrap native resources would usually clean up the native resource when the object is garbage collected. However it's not guaranteed when (or if at all) the GC will run. So it's possible that file handles or sockets get blocked for a long period of time or even pile up when you do several requests in succession. The explicit "Dispose" call will resolve this issue.

Of course you could call Dispose manually at the end, however the using statement ensures that Dispose is called, even when an exception happens inside the using block. Whenever the using block is exited, it will make sure Dispose is called.

So code like

Code (CSharp):

1. using (var www = UnityWebRequest.Post(uri, payload))
2. {
3.     // your code
4. }

would translate to something like

Code (CSharp):

1.  
2. {
3.     UnityWebRequest www;
4.     try
5.     {
6.         www = UnityWebRequest.Post(uri, payload))
7.         // your code
8.     }
9.     finally
10.     {
11.         www.Dispose();
12.     }
13. }

So no matter what happens, it would make sure Dispose is called at the end.

 

@Bunny83 Thank you sir for making this concept clear

 

That's odd. I tried the using statement here, and I'm still getting "A Native Collection has not been disposed, resulting in a memory leak."

I even tried taking it out of the using block, and manually calling Dispose() and it's still happening

Unity 2021.3.28f1

Edit: The solution was in this thread. The problem was I was sending json data, and needed to use new UnityWebRequest() instead of UnityWebRequest.Post

https://forum.unity.com/threads/unity-2021-unitywebrequest-native-collection-memory-leak.1175612/

 

I know this is old but it still appears a lot of people are struggling with it. For me simply disposing of the WebRequest did not work. What did work for me was disposing of each module of the WebRequest. Which looks like this:

Code (CSharp):

1. var webRequest = UnityWebRequest.Post(url, UnityWebRequest.kHttpVerbPOST);
2.  
3. webRequest.uploadHandler.Dispose();
4. webRequest.downloadHandler.Dispose();            
5. webRequest.Dispose();
6.  

 

This makes no sense as the Dispose method of the UnityWebRequest does dispose the up / download handlers if they exists. Have a look.

The auto-disposal of the handler could be disabled, however by default they would be disposed with the webrequest.

 

Oh okay I was not aware. Not sure why that change fixed it for me.

Do you have another fix? If I create a webrequest and then dispose of the object, it will still throw the error. Is it a unity bug?