Pretty Print XML

pretty-print-xml.ts

  prettyXml(xml: string) {
    try {
      const domParser = new DOMParser();
      const xmlDom = domParser.parseFromString(xml, 'application/xml');
      const xsltDom = domParser.parseFromString(
        `<xsl:stylesheet xmlns:xsl=http://www.w3.org/1999/XSL/Transform>
            <xsl:strip-space elements="*"/>
            <xsl:template match="para[content-style][not(text())]">
              <xsl:value-of select="normalize-space(.)"/>
            </xsl:template>
            <xsl:template match="node()|@*">
              <xsl:copy>
                <xsl:apply-templates select="node()|@*"/>
              </xsl:copy>
            </xsl:template>
            <xsl:output indent="yes"/>
          </xsl:stylesheet>`,
        'application/xml',
      );
 
      const xsltProcessor = new XSLTProcessor();
      xsltProcessor.importStylesheet(xsltDom);
      const resultDoc = xsltProcessor.transformToDocument(xmlDom);
      xml = new XMLSerializer().serializeToString(resultDoc);
    } catch (e) {}
    return xml;
  }