Adding Static Value to First Method of SOAP Message

You can add static values to the first method of SOAP message using XSLT. You can add static values such as username and password to the first child node within Body.

If soapenv in line 2 is different from the one in xml (soap, sp, etc.), it adds the new fields with namespace.

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" version="1.0">
  <xsl:output encoding="UTF-8" indent="yes" method="xml" version="1.0" />
  <xsl:strip-space elements="*" />
  <xsl:template match="@*|node()">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()" />
    </xsl:copy>
  </xsl:template>
  <xsl:template match="soapenv:Body/child::node()">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()" />
      <kullaniciAd>1</kullaniciAd>
      <sifre>2</sifre>
    </xsl:copy>
  </xsl:template>
</xsl:stylesheet>

Alternative Method

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:S="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns0="http://ws.sgk100wsV2.sgk.gov.tr/" version="1.0">
  <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes" />
  <xsl:strip-space elements="*" />
  <xsl:template match="@*|node()">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()" />
    </xsl:copy>
  </xsl:template>
  <xsl:template match="/S:Envelope/S:Body/*[1]">
    <xsl:copy>
      <arg0>
        <xsl:copy-of select="//*[local-name() = 'arg0']/text()" />
      </arg0>
      <arg1>kullaniciAdi</arg1>
      <arg2>sifreDegeri</arg2>
      <arg3>arg3 degeri</arg3>
    </xsl:copy>
  </xsl:template>
  <xsl:template match="/S:Envelope/S:Header">
    <xsl:copy-of select="/S:Envelope/S:Header" />
  </xsl:template>
</xsl:stylesheet>