Get public Distribution List email addresses from Microsoft EWS with Javascript, for MS Office JS API

getEmailAddressesFromEwsDistributionList.js

// this will get an Array of Email addresses from Public Distribution List stored in Exchange Server
getDLFromEws('[email protected]', (err, res) => {
  if (!err) {
    console.log(res)
  }
})

function getDLFromEws (emailAddress, callback) {
  const DLRequest = generateDistributionListSoapRequest(emailAddress)
  console.log('request:', prettifyXml(DLRequest))

  if (validateXML(DLRequest)) {
    Office.context.mailbox.makeEwsRequestAsync(DLRequest, function (result) {
      console.log('response:', result.value)

      const res = $.parseXML(result.value)
      const emailAddresses = res.getElementsByTagName('t:EmailAddress')
      const emails = []
      for (const ele of emailAddresses) {
        emails.push(ele.textContent)
      }
      callback(null, emails)
    })
  } else {
    console.error('invalid XML', prettifyXml(DLRequest))
    callback(Error('invalid XML'))
  }
}

// generate distribution list SOAP request
function generateDistributionListSoapRequest (emailAddress) {
  const result =
    '<?xml version="1.0" encoding="utf-8"?>' +
    '<soap:Envelope xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"' +
    '               xmlns:xsd="https://www.w3.org/2001/XMLSchema"' +
    '               xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"' +
    '               xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">' +
    '  <soap:Body>' +
    '    <ExpandDL xmlns="http://schemas.microsoft.com/exchange/services/2006/messages"' +
    '              xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">' +
    '      <Mailbox>' +
    '        <t:EmailAddress>' + emailAddress + '</t:EmailAddress>' +
    '      </Mailbox>' +
    '    </ExpandDL>' +
    '  </soap:Body>' +
    '</soap:Envelope>'

  return result
}

function prettifyXml (sourceXml) {
  const xmlDoc = new DOMParser().parseFromString(sourceXml, 'application/xml')
  const xsltDoc = new DOMParser().parseFromString([
    // describes how we want to modify the XML - indent everything
    '<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform">',
    '  <xsl:strip-space elements="*"/>',
    '  <xsl:template match="para[content-style][not(text())]">', // change to just text() to strip space in text nodes
    '    <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>',
  ].join('\n'), 'application/xml')

  const xsltProcessor = new XSLTProcessor()
  xsltProcessor.importStylesheet(xsltDoc)
  const resultDoc = xsltProcessor.transformToDocument(xmlDoc)
  const resultXml = new XMLSerializer().serializeToString(resultDoc)
  return resultXml
}

function validateXML (xmlString) {
  const domParser = new DOMParser()
  const dom = domParser.parseFromString(xmlString, 'text/xml')
  return dom.documentElement.nodeName !== 'parsererror'
}