xsi:nil Attribute is not supported in the xmldata Module

[daneshk]

Description

When converting XML to JSON using the xmldata:toJson() function, it returns empty strings for values of fields where the attribute xsi:nil="true" is present. These values should be null.

Steps to Reproduce

Consider the following Ballerina code:

import ballerina/xmldata;
import ballerina/io;

public function main() returns error? {
    xml x1 = xml `<name>Sherlock Holmes</name>
                  <details xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
                    <author xsi:nil="true"/>
                    <language>English</language>
                  </details>`;
    json jsonValue = check xmldata:toJson(x1, {preserveNamespaces: false});
    io:println(jsonValue.toJsonString());
}

Expected output:

{"name":"Sherlock Holmes", "details":{"author":null, "language":"English"}}

Actual output:

{"name":"Sherlock Holmes", "details":{"author":"", "language":"English"}}

Reference: https://github.com/wso2-enterprise/internal-support-ballerina/issues/854

Version

Latest

Environment Details (with versions)

No response