XSL substring and indexOf

Question

I m new to XSLT  I wonder if it is possible to select a substring of an item  I m trying to parse an RSS feed  The description value has more text than what I want to show  I d like to get a subtring of it based on the index of some substring  Basically  I want to show the result of a substring call passing  indxOf  some substring   and a length as parameters  Is this possible   From comments      I want to select the text of a string   that is located after the occurrence   of substring

User · Answer

The following is the complete example containing both XML and XSLT where substring-before and substring-after are used

<?xml version="1.0" encoding="UTF-8"?>
<persons name="Group_SOEM">
    <person>
        <first>Joe Smith</first>
        <last>Joe Smith</last>
        <address>123 Main St, Anycity</address>
    </person>
</persons>

The following is XSLT which changes value of first/last name by separating the value by space so that after applying this XSL the first name element will have value "Joe" and last "Smith".

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="first">
    <first>
        <xsl:value-of select="substring-before(.,' ')" />
    </first>
</xsl:template> 
<xsl:template match="last">
    <last>
        <xsl:value-of select="substring-after(.,' ')" />
    </last>
</xsl:template> 
<xsl:template match="@* | node()">
    <xsl:copy>
        <xsl:apply-templates select="@* | node()" />
    </xsl:copy>
</xsl:template>
</xsl:stylesheet>

User · Answer

It s not clear exactly what you want to do with the index of a substring  update  it is clearer now - thanks  but you may be able to use the function substring-after or substring-before   substring-before  My name is Fred    Fred     returns  My name is     If you need more detailed control  the substring   function can take two or three arguments  string  starting-index  length  Omit length to get the whole rest of the string   There is no index-of   function for strings in XPath  only for sequences  in XPath 2 0   You can use string-length substring-before  string   substring   1 if you specifically need the position   There is also contains  string   substring   These are all documented here  In XPath 2 0 you can use regular expression matching    XSLT mostly uses XPath for selecting nodes and processing values  so this is actually more of an XPath question  I tagged it thus

User · Answer

I want to select the text of a string   that is located after the occurrence   of substring   You could use    substring-after  string  match    If you want a subtring of the above with some length then use   substring substring-after  string  match  1  length    But problems begin if there is no ocurrence of the matching substring    So  if you want a substring with specific length located after the occurrence of a substring  or from the whole string if there is no match  you could use   substring substring-after  string substring-before  string  match              string-length  match    contains  string  match    1             length

User · Answer

Here is some one liner xpath 1 0 expressions for IndexOf   text   searchString     If you need the position of the FIRST character of the sought string  or 0 if it is not present   contains  text  searchString   1   string-length substring-before  text  searchString      If you need the position of the first character AFTER the found string  or 0 if it is not present   contains  text  searchString   1   string-length substring-before  text  searchString     string-length  searchString     Alternatively if you need the position of the first character AFTER the found string  or length 1 if it is not present   1   string-length  right  - string-length substring-after  right  searchString     That should cover most cases that you need   Note  The multiplication by contains        causes the true or false result of the contains        function to be converted to 1 or 0  which elegantly provides the  0 when not found  part of the logic

User · Answer

I wrote my own index-of function  inspired by strpos   in PHP   lt xsl function name  quot fn strpos quot  gt       lt xsl param name  quot haystack quot   gt       lt xsl param name  quot needle quot   gt       lt xsl value-of select  quot fn  strpos  haystack   needle  1  string-length  haystack  - string-length  needle   quot   gt   lt  xsl function gt    lt xsl function name  quot fn  strpos quot  gt       lt xsl param name  quot haystack quot   gt       lt xsl param name  quot needle quot   gt       lt xsl param name  quot pos quot   gt       lt xsl param name  quot count quot   gt       lt xsl choose gt           lt xsl when test  quot  count  amp lt  0 quot  gt               lt  -- Not found  Most common is to return -1 here  or maybe 0 in XSL    -- gt               lt  -- But this way  the result can be used with substring   without checking  -- gt               lt xsl value-of select  quot string-length  haystack    1 quot   gt           lt  xsl when gt           lt xsl when test  quot starts-with substring  haystack   pos    needle  quot  gt               lt xsl value-of select  quot  pos quot   gt           lt  xsl when gt           lt xsl otherwise gt               lt xsl value-of select  quot fn  strpos  haystack   needle   pos   1   count - 1  quot   gt           lt  xsl otherwise gt       lt  xsl choose gt   lt  xsl function gt

User · Answer

There is a substring function in XSLT  Example here

[xslt] XSL substring and indexOf

Examples related to xslt

Examples related to xpath