Modify repeating word/text in XML based on matching text/parameters?

Question

I have an XML file, containing the following:

  <SubtitleTracks>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>false</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>1</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>false</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>2</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
  </SubtitleTracks>

The <SubtitleTrack> section can repeat numerous times throughout the file.

However the structure is always the exact same. The only thing that changes in this section is this:

<SourceId>0</SourceId>
<TrackNumber>1</TrackNumber>

then the next one will be:

<SourceId>0</SourceId>
<TrackNumber>2</TrackNumber>

and so on...

Right now, <Default>false</Default> is always the case.

What I would like to do is change <Default>false</Default> to <Default>true</Default> only when SourceId is 0 and TrackNumber is 1.

Can anyone please help translate these requirements into a batch file?

EDIT: I think I have almost got this, but it is choking on something, as the result I keep getting is <Default>false</Default> false

@ECHO OFF
SETLOCAL
SET "sourcedir=C:\Test"
SET "destdir=C:\Test"
SET "filename1=%sourcedir%\TestOutput.txt"
SET "outfile=%destdir%\TestOutputFixed.txt"
SET "hotsection="
CALL :clear$

(
FOR /f "usebackqdelims=" %%a IN ("%filename1%") DO (
 rem if line contains `<SubtitleTrack>` we've entered hot section
 ECHO "%%a"|FIND "<SubtitleTrack>">NUL
 IF NOT ERRORLEVEL 1 SET "hotsection=y"
 SET "saved="
 IF DEFINED hotsection (
  FOR /L %%r IN (100,1,999) DO IF NOT DEFINED saved IF NOT DEFINED $%%r SET "$%%r=%%a"&SET "saved=Y"
  rem if line contains `</SubtitleTrack>` or `</SubtitleTracks>` then end-of-hotsection
  SET "endhot="
  SET "endtrack="
  FOR /f "tokens=1delims= " %%w IN ("%%a") DO FOR %%x IN ("</SubtitleTrack>") DO IF "%%w"==%%x SET "endhot=Y"&IF 

"</SubtitleTracks>"==%%x SET "endtrack=Y"
  IF DEFINED endhot (
   rem end-of-hotsection
   rem check whether we have SourceID 0 and TrackNumber 1
   SET "id0="&SET "track1="
   FOR /f "tokens=1,*delims== " %%r IN ('SET $') DO (
    IF "%%s"==""<SourceId>0" SET "id0=Y" 
    IF "%%s"==""<TrackNumber>1" SET "track1=Y" 
   )
   rem found end-of-hotsection. now regurgitate saved lines and set `default` appropriately
   FOR /f "tokens=2delims==" %%r IN ('SET $') DO (
    echo "%%r"|FINDSTR /r /c:" *\<Default>" >NUL
    IF ERRORLEVEL 1 (ECHO %%r) ELSE (
     FOR /f "tokens=1delims=:" %%s IN ("%%r") DO (
      IF defined track1 (IF DEFINED id0 (ECHO %%s true,) ELSE (ECHO %%s false,)) ELSE (ECHO %%s false,)
     )
    )
    CALL :clear$
    IF DEFINED endtrack SET "hotsection="
   )
  )
 ) ELSE (ECHO %%a)
)
)>"%outfile%"

GOTO :EOF

:clear$
:: remove variables starting $
FOR  /F "delims==" %%z In ('set $ 2^>Nul') DO SET "%%z="
GOTO :EOF

Regex are the wrong tool to use here, have you considered using XSLT? — Allan, May 22 '19 at 02:24
Beware all ye who enter here. https://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454 — lit, May 22 '19 at 13:20
I have added some comments to my answer, can you check if it works for you? — Allan, May 22 '19 at 23:14

score 2 · Accepted Answer · answered May 22 '19 at 02:49

Input XML file:

$ cat subtitletracks.xml 
  <SubtitleTracks>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>false</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>1</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>false</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>2</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
  </SubtitleTracks>

Transformation sheet:

$ cat subtitletransform.xslt 
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"  >

    <!-- copy all nodes and attributes -->
    <xsl:template match="@*|node()">
        <xsl:copy>
            <xsl:apply-templates select="@*|node()"/>
        </xsl:copy>
    </xsl:template>

    <!-- when find a default node for which the SourceId = 0 and trackNumber = 1 -->
    <xsl:template match="//SubtitleTrack/Default[../SourceTrack/SourceId = '0' and ../SourceTrack/TrackNumber = '1']">
        <xsl:copy>
            <xsl:apply-templates select="@*"/>
            <!-- assign value to true -->
            <xsl:value-of select="'true'"/>
        </xsl:copy>
    </xsl:template>

</xsl:stylesheet>

Output:

$ xsltproc subtitletransform.xslt subtitletracks.xml 
<?xml version="1.0"?>
<SubtitleTracks>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>true</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>1</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>false</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>2</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
  </SubtitleTracks>

Notes:

On windows to run XSLT processor via command line have a look at: Are there any XSLT processing command line tools?

I have tried this out using libxslt-1.1.26.win32. It runs successfully with no errors against the file, but the output does not change for me like above for you. Default remains as false. What am I missing? — StrangeThings, May 22 '19 at 03:40
@StrangeThings: That's very strange... Can you try with another tool? Or even directly via `saxon`? — Allan, May 22 '19 at 06:45
@StrangeThings: you need to redirect the output of the command to a new file `xsltproc.exe -v subtitletransform.xslt subtitletracks.xml > new_file.xml` — Allan, May 22 '19 at 22:15
@StrangeThings: you can also use option `-o output.xml` to define the output file to write to http://xmlsoft.org/XSLT/xsltproc.html — Allan, May 22 '19 at 23:12
output message "Warning: program compiled against libxml 207 using older 206" — StrangeThings, May 22 '19 at 23:40
@StrangeThings: perfect!!! If I have solved your question could you accept my answer/upvote? Thanks — Allan, May 23 '19 at 00:32

Dudi Boy · Answer 2 · 2019-05-22T11:43:10.007

Your restriction to implement with CMD batch file is adding complexity and degrading performance.

Batch files are used to integrate and synch program execution.

Your task is more about text/xml processing program.

A more suitable tool will be perl/python/awk scripts. These languages are designed for text processing.

Here is a sample 6 lines awk program:

awk '
pass1 && /<Default>false<\/Default>/ {markedLine = NR} 
pass1 && /<SourceId>0<\/SourceId>/ {sourceIdFlag = 1; next}
pass1 && sourceIdFlag && /<TrackNumber>1<\/TrackNumber>/ {markedLinesArr[markedLine] = 1}
pass1 {sourceIdFlag = 0}
!pass1 && markedLinesArr[FNR] == 1 {print "      <Default>true</Default>";next}
!pass1 {print}
' pass1=1 input.xml pass1=0 input.xml

Output

  <SubtitleTracks>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>true</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>1</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
    <SubtitleTrack>
      <IsNotifying>true</IsNotifying>
      <Burned>false</Burned>
      <Default>false</Default>
      <Forced>false</Forced>
      <SourceTrack>
        <SourceId>0</SourceId>
        <TrackNumber>2</TrackNumber>
        <Language>English [VOBSUB]</Language>
        <LanguageCode>eng</LanguageCode>
        <SubtitleType>VobSub</SubtitleType>
      </SourceTrack>
      <SrtOffset>0</SrtOffset>
      <SubtitleType>VobSub</SubtitleType>
    </SubtitleTrack>
  </SubtitleTracks>

Modify repeating word/text in XML based on matching text/parameters?

2 Answers2

Here is a sample 6 lines awk program:

Output