set-body policy not working

Question

My APIM is receiving request payload in below format -

--newreq
GET Abc?$format=json HTTP/1.1
--newreq
GET Abc?$format=json HTTP/1.1
--endreq--

and I have to format and send to backend in following format --

--newreq
Content-Type: application/http
Accept: application/json

GET Abc?$format=json HTTP/1.1


--newreq
Content-Type: application/http
Accept: application/json

GET Abc?$format=json HTTP/1.1

--newreq--

I have to add the 2 parameters after every --newreq line and append 2 new lines after GET request line.

I have added below policy but it is only appending data after only first --newreq.

Below is my policy

<set-body>@{
                string inBody = context.Request.Body.As<string>(preserveContent: true);
                string[] textSplit = inBody.Split();
                string newbody = string.Empty;
                string strpostBody= "Content-Type:"+"application/http"+" "+"Accept:"+"application/json";
                foreach (string val in textSplit)
                {
                    if (val == "--newreq")
                    {
                        int indexofbatch = inBody.IndexOf("--newreq");
                        if(indexofbatch >= 0)
                        {
                            newbody = inBody.Insert(indexofbatch + "--newreq".Length," "+strpostBody+" ");
                        }
                    }
                }
                return newbody.ToString();
        }</set-body>

Answer 1

@Suresh Thakur, Kirti APIM does support C# 7 in the policy expression. You can refer to API Management Policy Expressions documents for more details on .NET Framework types allowed in policy expressions.

Input Body:

--newreq  
GET Abc?$format=json HTTP/1.1  
--newreq  
GET Abc?$format=json HTTP/1.1  
--endreq--  

Policy Expression:

<set-body>@{  
                    string inBody = context.Request.Body.As<string>(preserveContent: true);  
                    string[] textSplit = Regex.Split(inBody, "--newreq");  
                    string newString = String.Empty;  
                    string strpostBody = "Content-Type:" + "application/http" + "\n" + "Accept:" + "application/json";  
      
                    for(int i=0; i < textSplit.Length-1;i++)  
                    {  
                        newString += "--newreq \n" + strpostBody + textSplit[i+1];  
                    }  
                    return newString;  
            }</set-body>  

The below body is set:
--newreq
Content-Type:application/http
Accept:application/json
GET Abc?$format=json HTTP/1.1
--newreq
Content-Type:application/http
Accept:application/json
GET Abc?$format=json HTTP/1.1
--endreq--

You can modify the c# expression as per your need and test different use cases. Feel free to get back to me if you need any assistance.