How to pass parameters by POST to an Azure function?

Question

I\'m trying to do a simple Azure Function to learn about it. There will be 3 functions:

• 1 function to insert a row into a table of a database. This table will

Answer 1

I have done a very simple example to get data using POST request in Azure Function App. Please find the following example.

using System;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Azure.WebJobs.Host;

namespace MyFunctions
{
    public static class MyFunctionsOperations
    {
        [FunctionName("MyFunctionsOperations")]
        public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]HttpRequestMessage req, TraceWriter log)
        {
            log.Info("C# HTTP trigger function processed a request.");
            var headers = req.Headers;
            string collection = headers.GetValues("collection").First();   //getting parameter from header

            CosmosdbOperation obj = new CosmosdbOperation();
            dynamic data = await req.Content.ReadAsAsync<object>();  //getting body content
            Boolean response = await obj.MyFunctionExecution(data.ToString(), collection);

            return (response)
                ? req.CreateResponse(HttpStatusCode.BadRequest, "Please pass a proper argument in the request body")
                : req.CreateResponse(HttpStatusCode.OK, "Operation successfully executed..");
        }
    }
}

Answer 2

It can be done in following way with custom class

Azure Function

[FunctionName("PostParameterFunction")]
public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)]HttpRequestMessage req, ILogger log)
   {
      log.LogInformation("C# HTTP trigger function processed a request.");

       try
        {
             // Convert all request perameter into Json object

                var content = req.Content;
                string jsonContent = content.ReadAsStringAsync().Result;
                dynamic requestPram = JsonConvert.DeserializeObject<RequestModel>(jsonContent);

                // Validate the required param

                if (string.IsNullOrEmpty(requestPram.FirstName))
                {
                    return req.CreateResponse(HttpStatusCode.OK, "Please enter First Name!");
                }
                if (string.IsNullOrEmpty(requestPram.LastName))
                {
                    return req.CreateResponse(HttpStatusCode.OK, "Please enter Last Name!");
                }


                //Create object for partner Model to bind the response on it

                RequestModel objRequestModel = new RequestModel();

                objRequestModel.FirstName = requestPram.FirstName;
                objRequestModel.LastName = requestPram.LastName;

                //Return Request Model

                return req.CreateResponse(HttpStatusCode.OK, objRequestModel);
         }
        catch (Exception ex)
         {

                return req.CreateResponse(HttpStatusCode.OK, "Cannot Create Request! Reason: {0}", string.Format(ex.Message));
         }

        }

Request Class:

 public class RequestModel
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }

    }

Request Input:

{
    "FirstName": "Kiron",
    "LastName":"Test"
}

PostMan Output Example:

Answer 3

In case google took you here, this is how it's done in March 2019 (Azure Functions v3):

public static async void Run(
            [HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]
            HttpRequest req,
            ILogger log)
        {
            var content = await new StreamReader(req.Body).ReadToEndAsync();

            MyClass myClass = JsonConvert.DeserializeObject<MyClass>(content);
            
        }

Answer 4

For passing parameters as POST request, you need to do following things:

1. Make Json model of the parameters that u need to pass,ex:

   {"UserProfile":{ "UserId":"xyz1","FirstName":"Tom","LastName":"Hank" }}
   

2. Post your data model using client like POSTMAN

3. Now you will get the posted content in HttpRequestMessage body, sample code is as follows:

   [FunctionName("TestPost")]
   public static HttpResponseMessage POST([HttpTrigger(AuthorizationLevel.Function, "put", "post", Route = null)]HttpRequestMessage req, TraceWriter log)
   {
       try
       {
           //create redis connection and database
           var RedisConnection = RedisConnectionFactory.GetConnection();
           var serializer = new NewtonsoftSerializer();
           var cacheClient = new StackExchangeRedisCacheClient(RedisConnection, serializer);
   
           //read json object from request body
           var content = req.Content;
           string JsonContent = content.ReadAsStringAsync().Result;
   
           var expirytime = DateTime.Now.AddHours(Convert.ToInt16(ConfigurationSettings.AppSettings["ExpiresAt"]));
   
           SessionModel ObjModel = JsonConvert.DeserializeObject<SessionModel>(JsonContent);
           bool added = cacheClient.Add("RedisKey", ObjModel, expirytime); //store to cache 
   
           return req.CreateResponse(HttpStatusCode.OK, "RedisKey");
       }
       catch (Exception ex)
       {
           return req.CreateErrorResponse(HttpStatusCode.InternalServerError, "an error has occured");
       }
   }
   

Answer 5

You need to attach data to the body of the post request and process it properly:

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log) {
    // This reads your post request body into variable "data"
    string data = await req.Content.ReadAsStringAsync();
    // Here you can process json into an object
    dynamic parsed = JsonConvert.DeserializeObject(data);

    return exitstring == null
        ? req.CreateResponse(HttpStatusCode.BadRequest, "Something went wrong, sorry")
        : req.CreateResponse(HttpStatusCode.OK);
}

You can find a slightly different example here and the exact example here.

Answer 6

To get the request content from the request body(post request), you could use req.Content.ReadAsAsync method. Here is the code sample.

Sample request body.

{
    "name": "Azure"
}

Define a class to deserialize the post data.

public class PostData
{
    public string name { get;set; }    
}

Get the post data and display it.

PostData data = await req.Content.ReadAsAsync<PostData>();
log.Info("name:" + data.name);

Client side code to send the post request.

HttpWebRequest req = (HttpWebRequest)WebRequest.Create("function-url");
req.Method = "POST";
req.ContentType = "application/json";
Stream stream = req.GetRequestStream();
string json = "{\"name\": \"Azure\" }";
byte[] buffer = Encoding.UTF8.GetBytes(json);
stream.Write(buffer,0, buffer.Length);
HttpWebResponse res = (HttpWebResponse)req.GetResponse();