re = /(?:(?!<(?:field|exclGroup)(?!\w)(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)[\S\s])*(?><(field|exclGroup)(?=(?:[^>"']|"[^"]*"|'[^']*')*?\sname\s*=\s*(?:(['"])([\S\s]*?)\2))\s+(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)(?:(?&core)|)<\/\1\s*>(?:(?!<(?:field|exclGroup)(?!\w)(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)[\S\s])*(?(DEFINE)(?<core>(?>(?><([\w:]+)(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)(?:(?&core)|)<\/\5\s*>|(?!<\/[\w:]+\s*>)(?>[\S\s]))+))/
str = '<field xmlns="http://www.xfa.org/schema/xfa-template/2.8/" y="0in" x="0.343mm" w="8.881pt" h="9.108pt" name="detcon_recreation_only">
<ui>
<checkButton size="8.881pt">
<border>
<edge stroke="lowered"/>
<fill/>
</border>
</checkButton>
</ui>
<font size="0pt" typeface="Adobe Pi Std"/>
<para vAlign="middle"/>
<value>
<text>0</text>
</value>
<items>
<text>1</text>
<text>0</text>
<text/>
</items>
</field>
<field xmlns="http://www.xfa.org/schema/xfa-template/2.8/" name="detcon_special_housing" y="5.393mm" w="27.94mm" h="4.134mm" x="0.343mm">
<ui>
<choiceList>
<border>
<edge stroke="lowered"/>
</border>
<margin/>
</choiceList>
</ui>
<font typeface="Arial Narrow" size="6pt"/>
<margin topInset="0mm" bottomInset="0mm" leftInset="0mm" rightInset="0mm"/>
<para vAlign="middle"/>
<value>
<text>NA</text>
</value>
<items>
<text>Not Applicable</text>
<text>Hotel Component</text>
</items>
<items save="1" presence="hidden">
<text>NA</text>
<text>HC</text>
</items>
</field>
<exclGroup xmlns="http://www.xfa.org/schema/xfa-template/2.8/" name="detcon_photo_taken" x="0in" y="0in">
<?templateDesigner itemValuesSpecified 1?>
<field w="12.446mm" h="3.825mm" name="lb_yes">
<ui>
<checkButton size="1.7639mm" shape="round">
<border>
<?templateDesigner StyleID apcb1?>
<edge/>
<fill/>
</border>
</checkButton>
</ui>
<font typeface="Myriad Pro"/>
<margin leftInset="1mm" rightInset="1mm"/>
<para vAlign="middle"/>
<caption placement="right" reserve="7.698mm">
<para vAlign="middle" spaceAbove="0pt" spaceBelow="0pt" textIndent="0pt" marginLeft="0pt" marginRight="0pt"/>
<font size="8pt" typeface="Arial Narrow" baselineShift="0pt"/>
<value>
<text>YES</text>
</value>
</caption>
<value>
<text xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/>
</value>
<items>
<text>1</text>
</items>
</field>
<field w="28.702mm" h="3.825mm" name="lb_no" x="13.233mm">
<ui>
<checkButton size="1.7639mm" shape="round">
<border>
<?templateDesigner StyleID apcb1?>
<edge/>
<fill/>
</border>
</checkButton>
</ui>
<font typeface="Myriad Pro"/>
<margin leftInset="1mm" rightInset="1mm"/>
<para vAlign="middle"/>
<caption placement="right" reserve="23.954mm">
<para vAlign="middle" spaceAbove="0pt" spaceBelow="0pt" textIndent="0pt" marginLeft="0pt" marginRight="0pt"/>
<font size="8pt" typeface="Arial Narrow" baselineShift="0pt"/>
<value>
<text>NO (see comments)</text>
</value>
</caption>
<value>
<text xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/>
</value>
<items>
<text>0</text>
</items>
</field>
<border>
<edge presence="hidden"/>
</border>
<?templateDesigner expand 1?></exclGroup>'
subst = 'VALUES (12345,"$3","/Tx", "", "N", "Y"),\\r\\n'
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html