PostTester

using System.Collections;
using System.Collections.Generic;
using System.Text;
using UnityEngine;
using UnityEngine.Networking;

[RequireComponent(typeof(TextMesh))]
public class PostTester : MonoBehaviour {

    private TextMesh textmesh;

    [SerializeField]
    private string key;

    private string result;
    bool needsUpdate = false;

    StringBuilder log = new StringBuilder();

	// Use this for initialization
	void Start () {
        textmesh = gameObject.GetComponent<TextMesh>();

        if(string.IsNullOrEmpty(key))
        {
            Log("Requires key!");
            needsUpdate = true;
            return;
        }

        SendRequest();
    }
	
	// Update is called once per frame
	void Update () {
		if (!needsUpdate)
        {
            return;
        }
        textmesh.text = log.ToString();
        needsUpdate = false;
	}

    public void SendRequest()
    {
        StartCoroutine(RequestToken());
        StartCoroutine(PostToken());
    }

    private void Log(string text, bool isError=false)
    {
        if (!isError) {
            Debug.Log(text);
        } else {
            Debug.LogError(text);
        }
        log.AppendLine(text);
        needsUpdate = true;
    }

    // Unity 2017.3.1 responds with "Generic/unknown HTTP error"
    // https://issuetracker.unity3d.com/issues/networking-unitywebrequest-dot-post-returns-generic-slash-unknown-http-error?page=1#comments
    // Note: UnityWebRequest does not currently support POSTs with no data. You still need to use the WWW class for this?
    IEnumerator RequestToken()
    {
        Debug.Log("UWR POST");
        using (UnityWebRequest www = UnityWebRequest.Post("https://api.cognitive.microsoft.com/sts/v1.0/issueToken", ""))
        {
            www.SetRequestHeader("Ocp-Apim-Subscription-Key", key);
            www.chunkedTransfer = false;
            yield return www.SendWebRequest();

            if (www.isNetworkError || www.isHttpError)
            {
                Log("UWR Error: " + www.error);
            }
            else
            {
                // Save token as result
                result = www.downloadHandler.text;
                Log ("UWR Token:\n" + result);
            }
        }
    }
    
    IEnumerator PostToken()
    {
        Debug.Log("WWW POST");
        var headers = new Dictionary<string, string>();
        headers.Add("Ocp-Apim-Subscription-Key", key);
        headers.Add("Content-Type", "application/x-www-form-urlencoded");

        var form = new WWWForm();
        // This is the workaround for empty post body otherwise Unity responds with error: "Cannot create a data handler without payload data"
        form.AddField("", "");

        using (WWW www = new WWW("https://api.cognitive.microsoft.com/sts/v1.0/issueToken", form.data, headers))
        {
            yield return www;

            if (!string.IsNullOrEmpty(www.error))
            {
                Log("WWW Error: " + www.error);
            }
            else
            {
                // Save token as result
                result = www.text;
                Log("WWW Token:\n" + result);
            }
        }
    }

}