XSLT更新审批状态前如何校验当前字段值避免重复更新

你需要在原有XSLT基础上做3处调整即可实现要求的校验逻辑：

• 新增变量获取当前审批记录的现有状态值
• 简化邮件审批结果的识别逻辑，统一转小写后判断，减少冗余的大小写分支
• 新增外层判断条件，仅当现有审批状态为Pending且邮件识别到有效审批结果时，才生成更新指令，否则跳过更新操作，避免重复修改状态。

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msxsl="urn:schemas-microsoft-com:xslt">
<xsl:template match="/" name="Approval_Update">
    <!-- *********************** -->
    <!-- BEGIN: Define Variables -->
    <!-- *********************** -->
    
    <!-- find the profile link recid of the email sender -->
    <xsl:variable name="profilelink_recid">
    <!-- for each RelatedBusinessObject -->
      <xsl:for-each select="BusinessObjectList/BusinessObject/RelatedBusinessObjectList/RelatedBusinessObject/BusinessObject">
        <xsl:choose>
          <xsl:when test="@Name = 'Employee'">
            <xsl:for-each select="./FieldList/Field">
              <xsl:choose>
                <xsl:when test="@Name = 'RecId'">
                  <xsl:value-of select="."/>
                </xsl:when>
              </xsl:choose>
            </xsl:for-each>
          </xsl:when>
        </xsl:choose>
      </xsl:for-each>
    </xsl:variable>

    <!-- find the profile link category of the email sender -->
    <xsl:variable name="profilelink_cat">
      <!-- for each RelatedBusinessObject -->
      <xsl:for-each select="BusinessObjectList/BusinessObject/RelatedBusinessObjectList/RelatedBusinessObject/BusinessObject">
        <xsl:choose>
          <xsl:when test="@Name = 'Employee'">
            <xsl:value-of select="'Employee'"/>
          </xsl:when>
        </xsl:choose>
      </xsl:for-each>
    </xsl:variable>
    
    <!-- find subject and subjectID -->
    <xsl:variable name="emailSubject" select = "BusinessObjectList/BusinessObject/EmailMessage/Subject" />
    <xsl:variable name="emailSubjectID" select = "BusinessObjectList/BusinessObject/EmailMessage/SubjectID" />
    <xsl:variable name="emailBody" select = "BusinessObjectList/BusinessObject/EmailMessage/Body" />
    <xsl:variable name="EmailStatus" select="substring-before($emailBody,' ')"/>
    
    <!-- 新增：获取当前审批记录的现有状态 -->
    <xsl:variable name="currentApprovalStatus" select="BusinessObjectList/BusinessObject[@Name='FRS_ApprovalVoteTracking']/FieldList/Field[@Name='Status']/text()" />
    
    <!-- 新增：识别邮件中的有效审批结果 -->
    <xsl:variable name="targetStatus">
        <xsl:choose>
            <xsl:when test="contains(lower-case($EmailStatus),'approve')">Approved</xsl:when>
            <xsl:when test="contains(lower-case($EmailStatus),'deny')">Denied</xsl:when>
            <xsl:otherwise></xsl:otherwise>
        </xsl:choose>
    </xsl:variable>

    <!-- 新增：校验条件，仅当现有状态为Pending且有有效审批结果时才执行更新 -->
    <xsl:if test="$currentApprovalStatus = 'Pending' and $targetStatus != ''">
        <xsl:for-each select="BusinessObjectList/BusinessObject">   
            <xsl:element name="BusinessObject">
                <xsl:attribute name="Name"><xsl:value-of select="'FRS_ApprovalVoteTracking'"/></xsl:attribute>
                <!-- Set Transaction as 'Update'.  It will try to update existing record using UniqueKey value, otherwise it will fail. -->
                <xsl:element name="Transaction">Update</xsl:element>
                <!--Unique Key List-->
                <xsl:element name="UniqueKeyList">
                    <xsl:element name="UniqueKey">
                        <xsl:element name="Field">
                            <xsl:attribute name="Name"><xsl:value-of select="'TrackingID'"/></xsl:attribute>
                        </xsl:element>
                    </xsl:element>
                </xsl:element>
                <FieldList>
                    <!-- Fields -->
                    <xsl:for-each select="EmailMessage/node()">
                        <xsl:choose>
                            <xsl:when test="name() = 'SubjectID'">
                                <xsl:element name="Field">
                                    <xsl:attribute name="Name"><xsl:text>TrackingID</xsl:text></xsl:attribute>
                                    <xsl:attribute name="Type">System.Int32</xsl:attribute>
                                    <xsl:value-of select="."/> 
                                </xsl:element>
                            </xsl:when>
                            <xsl:when test="name() = 'Body'">
                                <xsl:element name="Field">
                                    <xsl:attribute name="Name"><xsl:text>Status</xsl:text></xsl:attribute>
                                    <xsl:value-of select="$targetStatus"/>
                                </xsl:element> 

                                <xsl:element name="Field">
                                    <xsl:attribute name="Name"><xsl:text>Reason</xsl:text></xsl:attribute>
                                    <xsl:choose>
                                        <xsl:when test="$targetStatus = 'Denied'">
                                            <xsl:text>Denied by Email</xsl:text>
                                        </xsl:when>
                                        <xsl:otherwise>
                                            <xsl:text></xsl:text>
                                        </xsl:otherwise>
                                    </xsl:choose>
                                </xsl:element>
                            </xsl:when>
                        </xsl:choose>
                    </xsl:for-each>
                </FieldList>
                <!-- Copy the RelatedBusinessObjectList element-->
                <xsl:element name="RelatedBusinessObjectList">
                    <xsl:for-each select="RelatedBusinessObjectList">
                        <xsl:copy-of select="node()"/>
                    </xsl:for-each>
                </xsl:element>
            </xsl:element>
        </xsl:for-each> 
    </xsl:if>
    </BusinessObjectList>
</xsl:template>
</xsl:stylesheet>

内容的提问来源于stack exchange，提问作者PaulMorton