Raw json body how to add variable?

[kizildagcenk (Cenk KIZILDAĞ)]

Hello,

How can I add variable to raw - json body?

 {
    "referenceId": "022078925508",
    "productCode": "001002461285",
    "quantity": "1",
    "version": "V1",
    "signature": {{Signature}},
    "applicationCode": "52e7cf966b724749a7c4efadc3727ed7"
}

Here is my pre-request script

var ApplicationCode = request.data["ApplicationCode"];
var Version=request.data["version"];
var ReferenceId=request.data["referenceId"];
var ProductCode=request.data["productCode"];
var Quantity=request.data["quantity"];
var SecretKey="e56067172e61";
var hashText = ApplicationCode+ProductCode+Quantity+ReferenceId+Version+SecretKey;
var encryption = CryptoJS.MD5(hashText).toString();

postman.setEnvironmentVariable("Signature", encryption);

[singhsivcan (Sivcan Singh)]

Hi @kizildagcenk, you’re using the correct method to set the variable in the pre-request script.
One thing I’d like to point out on the last line is that you can use pm.environment.set("Signature", encryption);
This is the new API and I recommend using it.

Also, in the raw body, you’ve to surround the Signature variable with quotes.
So your raw body actually becomes the following:

{
    "referenceId": "022078925508",
    "productCode": "001002461285",
    "quantity": "1",
    "version": "V1",
    "signature": "{{Signature}}", // notice the quotes here around the variable
    "applicationCode": "52e7cf966b724749a7c4efadc3727ed7"
}

Now run your script and it should work as expected.

[kizildagcenk (Cenk KIZILDAĞ)]

Thank you for your reply @singhsivcan, I m getting error from the service. I think they want content-type = application/x-www-form-urlencoded. Is there a way to convert this to application/x-www-form-urlencoded?

Best Regards.

[singhsivcan (Sivcan Singh)]

@kizildagcenk
You can try this:
Disable the first header.
And then you can add the other header like so:

Or if this fits your case then you can use the body type x-www-form-urlencoded instead of raw
This will automatically add the header too.

[davidbeinhart]

I know this is an older post/has been closed for a while. But is there a limit to the variable size? I am trying to get a description from a JIRA issue and use it as a variable to create another one.

The syntax you mention, “{{Variable}}”, works for me in Body Raw JSON when using variables such as Date or Title from the JIRA issue, but when using the description I am getting the following error:

{
“errorMessages”: [
“Illegal unquoted character ((CTRL-CHAR, code 13)): has to be escaped using backslash to be included in string value\n at [Source: org.apache.catalina.connector.CoyoteInputStream@7fc7314c; line: 13, column: 39]”
]
}

I am able to get the request to work when I copy in the description value into the JSON Body (even its entire length )

Any suggestions?

Edit:

So I was able to answer my own question.
Using stringify() to set my variable seems to fix my problem:

pm.environment.set(“description”, JSON.stringify(description));

[phuckhang.nguyen]

Thank you, @davidbeinhart. It works for me.

[arlem (Arlémi Turpault)]

Since this question is still pulling a lot of views we’ve created a collection that shows how to achieve that in the Postman Answers public workspace:

https://www.postman.com/postman/workspace/postman-answers/collection/9215231-f6b56d11-9a88-4785-8b78-ebd756b6c940?ctx=documentation

Fork it and see how it works by yourself!

[rikitzzz (Ricard Nikens Malla)]

Hi! I am in a similar situation, but this didn’t completely work for me. I have my request in a folder that contains a pre-request script to calculate an HMAC over the request’s body.

What seems to happen is that the pre-request script of the request is run after the pre-request of the folder, so I tried moving the

pm.collectionVariables.set('shopName', pm.environment.get('shopName'));

to the first line of the folder’s pre-request script but that still didn’t work.

This is what the pre-request script of the folder looks like:

const input = request.data;
const key = pm.environment.get("key");
const hmac = CryptoJS.enc.Base64.stringify(CryptoJS.HmacSHA256(input, key));
pm.environment.set("hmac",hmac)

Like I said, using the collectionVariables.set at the beginning of the script didn’t work. What worked was changing the first line to:

const input = request.data.replace("{{shopName}}",pm.environment.get("shopName"));

What is the best approach in a situation like this?

[bertelliedgard (Edgard Bertelli)]

You just made my day! Not in a million years would I imagine that the missing quotes were causing the empty array problem. Thanks!

[TechnocratsAdmin (Technocrats Kekan)]

you can find short demo explanation here how to add variable in json postman

[SparcBR (Elizandro Garcia Roos)]

It works, but does’t show the value of the variable on mouse over. Notice that the var name appears in italic.

[scheiblib94 (Bence)]

I’m in a similar situation, but it’s a little different.

{
    "items": [
   {
    "id":"123456" 
   },           
     {
    "id":"1234567" 
   }
]  
 }

What I want to achieve is to generate the items array elements, because I have to send 10.000 items in one POST request.
How can I replace the array’s items?

[danny-dainton]

Hey @scheiblib94

Welcome to the Postman Community!

You would need to do this:

{
    "items": {{array}}
}

You would need to add this to the pre-request to construct the request body:

let reqArray = [
   {
    "id":"123456" 
   },           
     {
    "id":"1234567" 
   }
]

pm.variables.set('array', JSON.stringify(reqArray));

It will be slightly different if you’re pulling that data from a variable but be you’re need to ensure that it’s in the correct format of it wouldn’t resolve the data correctly.