Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Dear monks,

I need help to convert the source format file to target format file, content detailed below:

Source 

<businesses>
    <entity name="Retail">
      <description>Products and items available in retail</description
+>
      <product min="0" max="3">
          <description>Product information</description>
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </product>
    </entity>
    <item name="Patrol">
          <description>Title</description>
          <text maxlength="80" size="65" />
    </item>
    <entity name="Sports">
      <description>Sports Items</description>
      <product min="0" max="3">
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </product>
    </entity>
</businesses>

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Target 

<businesses>
    <block name="Retail" min="0" max="3">
      <description>Products and items available in retail</description
+>
          <description>Product information</description>
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
    </block>
    <item name="Patrol">
          <description>Title</description>
          <text maxlength="80" size="65" />
    </item>
    <block name="Sports" min="0" max="3">
      <description>Sports Items</description>
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
    </block>
</businesses>

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This is the code snippet attempting the conversion.

It converts the begining tags(e.g cited below) for the first instance (conversion must happen at every occurance) 

<entity name="Retail">
      <description>Products and items available in retail</description
+>
      <product min="0" max="3">

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To 

    
<block name="Retail" min="0" max="3">
      <description>Products and items available in retail</description
+>

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Also the corresponding end tags need to be replaces as below

      </product>
    </entity>

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To 

    
    </block>

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Please Advice. 

    
########### Process the Input string ############
my $replstr ="<block ";
## The $strFile  holds the source string 
if($strFile =~ m/<product (.*)?>/)
{
  
  $range_rep = $1;
  $strFile =~ m/<product [^>]+>/;
  $str2relpace = "$`$&";           # This is the string to be replaced
  if($str2relpace =~ m/<\/(.*)?></)
  {
      $matchStr = "$'";
  }else
  {
      $matchStr =$str2relpace;
    }
  
  if($` =~ m/<description>.*<\/description>/)
  {
      $desc = $&;
  }

  $desc = "\n".$desc if($desc);
  $` =~ m/<item (.*)?>/;
  $elementName = $1;
  $eleVal=$1 if($elementName =~ m/\"(.*)\"/);
  
  # Constructing the replace string.
  $replstr .=$elementName." ".'location="'."$eleVal\" ". "$range_rep".
+'>';     # This is the replacing string
  
  $strFile =~ s/\Q$matchStr\E/$replstr$desc/g;   
  
  #$strFile =~ s/<\/product><\/entity>/<\/block>/ig;
  
  
  print "\n\n\n The output is ================= \n $strFile \n \n ====
+==============\n";
  
}

[download]

READMORE tags added by Arunbear

Replies are listed 'Best First'.
Re: String Manipulation Help Required
by rev_1318 (Chaplain) on Jun 29, 2005 at 07:25 UTC
    Don't try to write your own XML-parser/transformer. Use an existing one. Use XSLT, or, when you want to use Perl, use one of the many XML-parsing modules like XML::Parse or XML::Twig.

    Paul

[reply]
      Seconded. Perl is my tool of choice, but for this problem XSLT is the right way.

      Update: Added stylesheet 
      <?xml version='1.0' ?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" versi
+on="1.0">
  
  <xsl:output method="xml" indent="yes" />
  <xsl:preserve-space elements="*" />

  <xsl:template match="/businesses">
    <xsl:copy>
      <xsl:for-each select="./entity">
        <block>

          <xsl:attribute name="name">
            <xsl:value-of select="./@name" />
          </xsl:attribute>
          <xsl:attribute name="min">
            <xsl:value-of select="./child::product/@min" />
          </xsl:attribute>
          <xsl:attribute name="max">
            <xsl:value-of select="./child::product/@max" />
          </xsl:attribute>

          <xsl:for-each select = ".//description">
            <xsl:if test="name(./parent::*)!='item'">
              <xsl:copy>
                <xsl:value-of select = "." />
              </xsl:copy>
            </xsl:if>
          </xsl:for-each>

          <xsl:for-each select = ".//item">
              <xsl:copy-of select="." />
          </xsl:for-each>

        </block>
      </xsl:for-each>
    </xsl:copy>
  </xsl:template> 
</xsl:stylesheet>

      [download]


      holli, /regexed monk/
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Re: String Manipulation Help Required
by gopalr (Priest) on Jun 29, 2005 at 07:44 UTC

    TIMTOWDI

    $strFile='
<businesses>
    <entity name="Retail">
      <description>Products and items available in retail</description
+>
      <product min="0" max="3">
          <description>Product information</description>
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </product>
    </entity>
    <item name="Patrol">
          <description>Title</description>
          <text maxlength="80" size="65" />
    </item>
    <entity name="Sports">
      <description>Sports Items</description>
      <product min="0" max="3">
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </product>
    </entity>
</businesses>
';

$strFile=~s#<entity ([^>]+)>\s*(.+?)<product (min="[^"]+" max="[^"]+")
+>#<block $1 $3>\n$2#gs;
$strFile=~s#</product>\s*</entity>#</block>#gs;
print "\n$strFile";

    [download]

    Thanks,
    Gopal.R

[reply]
[d/l]

      Thanks Gopal.R

      Your solution is of great help. Thanks.

      The Regex failed when the "<entity></entity> is changed to "<item></item>". This was attempeted with the intention that the first level element have the same name.

      The Error can be over come, if "</item>" tag does not occur in the search string. Something like below

      $strFile=~s#<entity ([^>]+)>\s*(.+?)<i>negating regex here </i><produc
+t (min="[^"]+" max="[^"]+")

      [download]

      Please advice solution as I am a novice Regex Developer.

      Thanks in advance.

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Re: String Manipulation Help Required
by gellyfish (Monsignor) on Jun 29, 2005 at 11:01 UTC

    Others have suggested using XSLT but I thought it might be useful to actually show you how - here is the stylesheet: 

    <?xml version="1.0"?>
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
               version="1.0">
 
     <xsl:output method="xml" />
     <xsl:template match="/">
        <businesses>
           <xsl:apply-templates />
        </businesses>
     </xsl:template>
 
     <xsl:template match="entity">
        <block>
           <xsl:attribute name="name">
              <xsl:value-of select="@name" />
           </xsl:attribute>
           <xsl:attribute name="min">
              <xsl:value-of select="product/@min" />
           </xsl:attribute>
           <xsl:attribute name="max">
              <xsl:value-of select="product/@max" />
           </xsl:attribute>
           <xsl:copy-of select="description" />
           <xsl:copy-of select="product/*" />
        </block>
     </xsl:template>
     <xsl:template match="item">
        <xsl:copy-of select="." />
     </xsl:template>
</xsl:transform>

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    And of course code in Perl, first using XML::XSLT: 
    use XML::XSLT;
                                                                      
+          
my $xslt = XML::XSLT->new ('tr.xslt', warnings => 1);
                                                                      
+          
$xslt->transform ('source.xml');
print $xslt->toString;
                                                                      
+          
$xslt->dispose();

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    Secondly using XML::LibXSLT: 
    use XML::LibXSLT;
use XML::LibXML;
                                                                      
+          
my $parser = XML::LibXML->new();
my $xslt = XML::LibXSLT->new();
                                                                      
+          
my $source = $parser->parse_file('source.xml');
my $style_doc = $parser->parse_file('tr.xslt');
                                                                      
+          
my $stylesheet = $xslt->parse_stylesheet($style_doc);
                                                                      
+          
my $results = $stylesheet->transform($source);
                                                                      
+          
print $stylesheet->output_string($results);

    [download]

    /J\

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Re: String Manipulation Help Required
by anonymized user 468275 (Curate) on Jun 29, 2005 at 07:19 UTC
    The first thing I see here is that when matching whitespace in regexps use '\s' instead of ' '.

    For example: \<product\s+ to match the start of the product tag.

    One world, one people

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Re: String Manipulation Help Required
by prasadbabu (Prior) on Jun 29, 2005 at 07:22 UTC

    I have tried in another way using regex, but this can be done still more efficiently.

    $str = '<businesses>
    <entity name="Retail">
      <description>Products and items available in retail</description
+>
      <product min="0" max="3">
          <description>Product information</description>
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </product>
    </entity>
    <item name="Patrol">
          <description>Title</description>
          <text maxlength="80" size="65" />
    </item>
    <entity name="Sports">
      <description>Sports Items</description>
      <product min="0" max="3">
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </product>
    </entity>
</businesses>';

$str =~ s/(<entity)([^>]+)>((?:(?!(?:<product)).)*)(<product (min="[^"
+]*" max="[^"]*")>)/<block$2 $5>$3$4/gsi;
$str=~ s/<\/product>\s*<\/entity>/<\/block>/gsi;
print "$str";

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    This gives the following output.

    <businesses>
    <block name="Retail" min="0" max="3">
      <description>Products and items available in retail</description
+>
      <product min="0" max="3">
          <description>Product information</description>
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </block>
    <item name="Patrol">
          <description>Title</description>
          <text maxlength="80" size="65" />
    </item>
    <block name="Sports" min="0" max="3">
      <description>Sports Items</description>
      <product min="0" max="3">
        <item name="Title">
          <description>Title</description>
          <text maxlength="80" size="65" />
        </item>
      </block>
</businesses>

    [download]

    updated:

    Prasad

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