Using XSLT to transform XML to JSON

Question

I would like to use XSLT to transform some XML into JSON.
The XML looks like the following:

<DATA_DS>
    <G_1>
        <ORGANIZATION_NAME>My Company 1</ORGANIZATION_NAME>
        <ORGANIZATIONID>901</ORGANIZATIONID>
        <ITEMNUMBER>20001</ITEMNUMBER>
        <ITEMDESCRIPTION>Item Description 1</ITEMDESCRIPTION>
    </G_1>
    <G_1>
        <ORGANIZATION_NAME>My Company 1</ORGANIZATION_NAME>
        <ORGANIZATIONID>901</ORGANIZATIONID>
        <ITEMNUMBER>20002</ITEMNUMBER>
        <ITEMDESCRIPTION>Item Description 2</ITEMDESCRIPTION>
    </G_1>
    <G_1>
        <ORGANIZATION_NAME>My Company 1</ORGANIZATION_NAME>
        <ORGANIZATIONID>901</ORGANIZATIONID>
        <ITEMNUMBER>20003</ITEMNUMBER>
        <ITEMDESCRIPTION>Item Description 3</ITEMDESCRIPTION>
    </G_1>
</DATA_DS>

I expect the JSON to look like the following:

    [
        {
            "Item_Number":"20001",
            "Item_Description":"Item Description 1"
        },
        {
            "Item_Number":"20002",
            "Item_Description":"Item Description 2"
        },
        {
            "Item_Number":"20003",
            "Item_Description":"Item Description 3"
        }
    ]

What is the recommended way to do this?

I am considering two approaches:

1. Try using the fn:xml-to-json function, as defined at https://www.w3.org/TR/xpath-functions-31/#func-xml-to-json. But as I understand, the input XML must follow a specific format defined at: https://www.w3.org/TR/xpath-functions-31/schema-for-json.xsd. And I also need the field names in the output JSON to be specifically "Item_Number" and "Item_Description".

2. Manually code the bracket and brace characters, "[", "]", "{", and "}", along with the field names "Item_Number" and "Item_Description". Then use a standard function to list the values and ensure that any special characters are handled properly. For example, the "&" character should appear normally in the JSON output.

What is the recommended way to do this, or is there a better way that I have not considered?

Answer 1

I would take the first approach, but start with transforming the given input to the XML format expected by the xml-to-json() function. This could be something like:

XSLT 3.0

<xsl:stylesheet version="3.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns="http://www.w3.org/2005/xpath-functions">
<xsl:output method="text" encoding="UTF-8"/>

<xsl:template match="/G_1">
    <!-- CONVERT INPUT TO XML FOR JSON -->
    <xsl:variable name="xml">
        <array>
            <xsl:for-each-group select="*" group-starting-with="ORGANIZATION_NAME">
                <map>
                    <string key="Item_Number">
                        <xsl:value-of select="current-group()[self::ITEMNUMBER]"/>
                    </string>
                    <string key="Item_Description">
                        <xsl:value-of select="current-group()[self::ITEMDESCRIPTION]"/>
                    </string>
                </map>
            </xsl:for-each-group>
        </array>
    </xsl:variable>
    <!-- OUTPUT -->
    <xsl:value-of select="xml-to-json($xml)"/>
</xsl:template>

</xsl:stylesheet>

---

Demo: https://xsltfiddle.liberty-development.net/bFWR5DQ