XSLT - First Instance of Empty Node edit - xslt-1.0

Question

I am trying to edit the first instance of an empty node(Status) in the following xml :
<?xml version='1.0' encoding='windows-1252'?>
<root>
<row>
<flowname>1</flowname>
<path>#[payload]</path>
<id>3</id>
<setMessage>4</setMessage>
<MockOne>5</MockOne>
<MockTwo>6</MockTwo>
<MockThree>7</MockThree>
<Assert></Assert>
<status>12</status>
</row>
<row>
<flowname>2</flowname>
<path>4</path>
<id>5</id>
<setMessage>6</setMessage>
<MockOne>7</MockOne>
<MockTwo>8</MockTwo>
<MockThree></MockThree>
<Assert></Assert>
<status></status>
</row>
<row>
<flowname>3</flowname>
<path>5</path>
<id>6</id>
<setMessage>7</setMessage>
<MockOne>8</MockOne>
<MockTwo>9</MockTwo>
<MockThree></MockThree>
<Assert>3</Assert>
<status></status>
</row>
</root>
What I want to achieve is for the xslt to find the first instance of the tag which is empty and edit it to say 123. I tried using the following XSLT, but it seems to be replacing every Empty Status tag and I need it only to do the first instance. Kindly suggest on what has to be changed
The XSLT as follows:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="node()|#*">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="row/status[1][not(text())][1]">
<status>123</status>
</xsl:template>
</xsl:stylesheet>
The output right now is as follows( Every empty Status tag is replaced instead of the first instance of an empty one)
<root>
<row>
<flowname>1</flowname>
<path>#[payload]</path>
<id>3</id>
<setmessage>4</setmessage>
<mockone>5</mockone>
<mocktwo>6</mocktwo>
<mockthree>7</mockthree>
<assert></assert>
<status>12</status>
</row>
<row>
<flowname>2</flowname>
<path>4</path>
<id>5</id>
<setmessage>6</setmessage>
<mockone>7</mockone>
<mocktwo>8</mocktwo>
<mockthree></mockthree>
<assert></assert>
<status>123</status>
</row>
<row>
<flowname>3</flowname>
<path>5</path>
<id>6</id>
<setmessage>7</setmessage>
<mockone>8</mockone>
<mocktwo>9</mocktwo>
<mockthree></mockthree>
<assert>3</assert>
<status>123</status>
</row>
</root>

Answer 1

Your Xpath expression is saying to update all row/status which is empty.
You need to change like this:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="node()|#*">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="row[not(preceding-sibling::row[not(normalize-space(status))])]/status[1][not(text())][1]">
<status>123</status>
</xsl:template>
</xsl:stylesheet>