Dynamically set a XML tag value while building payload

Question

I am trying automate testing using Karate.

I have a XML payload.

I have a static XML payload which I am readying from a file and I want to call my service in loop.

For each call I would like to replace value for a tag name dynamically.

How would I achieve this?

e.g.

Below is my Main Feature which calls my common feature in loop

Feature: Loop Call
Background:
* def common = call read('classpath:CommonFeatures.feature')

Scenario:
* table table
    | payload_file    | field_tag  | field_value |
    | 'HappyPath.xml' | 'car_fuel' | 'Gas'     |
    | 'HappyPath.xml' | 'car_color'| 'Red'     |

* def response = call read('classpath:Car.feature')  table

Car.feature

Feature: Common
Scenario:
    * print payload_file
    * print field_tag
    * print field_value
    * xml payload = read('classpath:/payload/'+payload_file)
    * print payload
    * set payload/$field_tag = field_value

This is where I have issue setting the field_tag value.

I have other option to do this like writing a small java script method to replace the tag value or a small java class which use DOMParser or SAXParser to perform the same.

However I would like to know if there is any karate in build way to perform the same.

Also while using java script method to replace the tag value if I am using var parser = new DOMParser(); and it seems DOMParser is not available to use. Is there a way to make this available?

Answer 1

Thanks to Peter for all help and the examples.

I feel this is the best way to achieve this.

Wrote a small javascript function

   """
    * def replaceTag =
      """
      function(x){
        karate.setXml('temp', x.payload);
        karate.pretty(karate.get('temp'));
        if (x.field_tag) karate.set('temp', x.field_tag, x.field_value);
        return karate.get('temp');
      }
    """

and calling the same from Car.feature like below and I get the dynamically replaced payload.

Feature: Common
Scenario:
    * print payload_file
    * print field_tag
    * print field_value
    * xml payload = read('classpath:/payload/'+payload_file)
    * print payload
    * def args = { payload: #(payload), field_tag: #(field_tag), field_value: #
          (field_value)}
    * print args
    * xml payload = call common.replaceTag args

Note: I had to upgrade Karate 0.7.0 version in order to use karate.setXml method.