CODEWITHSUNDEEP
javascriptapipostman
deadandhallowed
deadandhallowed

Reputation: 40

How to change body of API POST request with script?

I just started learning about API an hour ago and wanted input on a little POST I wrote. My understanding of how all of this works is very wrong. More than anything, I would like to know how to pass a variable from script to the API request.

The body:

{
   "bot_id" : "abc123",
   "text" : words
}

And the pre-request script in javascript:

var num = Math.floor((Math.random() * 3) + 1);

switch(num)
{
    case 1:
        words = "Hello world!";
        break;
    case 2:
        words = "Greetings Earthlings.";
        break;
    case 3:
        words = "Goodbye cruel world!";
        break;
}

This is the response I get when it fails (400 Bad Request):

{
    "meta": {
        "code": 400,
        "errors": [
            "Invalid bot_id"
        ]
    },
    "response": null
}

Upvotes: 0

Views: 1130

Answers (1)

Roman
Roman

Reputation: 5220

The Response

The Response "errors": ["Invalid bot_id"] tells you that the bot_id (abc123) is wrong. May be there is some validation on the backend?

How to Pass Values to the Request

Inside the pre-request script you have access to the postman object. This object has the methods setGlobalVariable, getGlobalVariable, setEnvironmentVariable and getEnvironmentVariable.

Now with this methods you can read/write variables. In your case you want to use postman.setGlobalVariable('words', words). Inside the body you can use the variables by using curly braces {{variable}}

Code

Pre-Request Script

var num = Math.floor((Math.random() * 3) + 1);
var words = "";

switch(num) {
    case 1:
        words = "Hello world!";
        break;
    case 2:
        words = "Greetings Earthlings.";
        break;
    case 3:
        words = "Goodbye cruel world!";
        break;
}

postman.setGlobalVariable('words', words)

Body

{
    "bot_id" : "abc123",
    "text" : "{{words}}"
}

Upvotes: 1

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