title: How to give empty value for argument in POST request for hyperledger composer rest server
body: <p>I am trying to make a post request via R using the httr package to composer rest server. I have written a code and then created the composer rest server from it. These are my details</p>
  
  <p>Request URL : <a href="http://localhost:3000/api/nl.amis.registry.fruits" rel="nofollow noreferrer">http://localhost:3000/api/nl.amis.registry.fruits</a>
  <code>
  Body: {
  "$class": "nl.amis.registry.fruits",
  "Id": "9",
  "name": "orange",
  "description": "string",
  "count": ""
  }
  </code>
  First, I have tried with the composer rest server. For my purpose, I needed the count to be blank and the value will be appended by another API call. I was able to make the transaction successfully with the <strong>count: ""</strong>. This I was able to check in the test section of the composer playground. The remaining code works fine which appends the count variable later on. </p>
  
  <p>Now I am writing an R code to make a similar transaction through POST request. Here I am facing an error that <strong>"count cannot be blank"</strong> and returns with error <strong>422 Unprocessable entity</strong>. The content type I was used was <strong>application/json</strong>. While using the <strong>"count":{}</strong> , the post request process fine and i am getting <strong>"count":[object Object]</strong> in the response. But the later on code which does the appending will do something like <strong>count:"[object Object],1"</strong> wherein I am expecting <strong>"count":"1"</strong>. Everything works fine while using the test in composer playground but while trying to access externally via rest API is creating the problem. Please help.</p>