How to replace return ( | ) by the string "\n" in xslt 1.0 ? [XML multiline base64 to json]

Question

I got a xml that I need to turn into a json. I'm mostly fine except with a base64 multiline

<file>TU0...AAA
FOO...BCD
FOO...012
FOO...ZYX</file>

In json multiline is not possible, this should be rewritten in 1 line only as

"file":"TU0...AAA\nFOO...BCD\nFOO...012\nFOO...ZYX" 

With "real" two-char string "\n" to concatenate each line.

Can I do that in xslt 1.0 ?

I know I can use translate but that's for one char only. I'll try

translate(.,'
',' ') 

This will replace returns by space and maybe this won't break the base64 decoding of the json.

But, if i want to do it the "right way", I guess I'll need custom funcs. In my case returns seems to be " ". But if someone comes with a solution that works with all combinations ( ) that would be great.

My primary target is chrome web browser but running fine in all browsers would be great.

Answer 1

If you just want to get rid of the linefeeds you could use the normalize-space($string)function, e.g.:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xd="http://www.oxygenxml.com/ns/doc/xsl"
    exclude-result-prefixes="xd"
    version="1.0">
    <xd:doc scope="stylesheet">
        <xd:desc>
            <xd:p><xd:b>Created on:</xd:b> Apr 22, 2020</xd:p>
            <xd:p><xd:b>Author:</xd:b> bwb</xd:p>
            <xd:p>generates a normalized text output of the file element</xd:p>
        </xd:desc>
    </xd:doc>

    <xsl:output method="text"/>

    <xsl:template match="/">
        <xsl:apply-templates select="file"/>
    </xsl:template>

    <xsl:template match="file">
        <xsl:value-of select="normalize-space(.)"/>
    </xsl:template>

</xsl:stylesheet>

You could then still replace the whitespaces by something else( forJSON maybe with ,)

If you definitely want the \nthough, you could try the following stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:math="http://www.w3.org/2005/xpath-functions/math"
    xmlns:xd="http://www.oxygenxml.com/ns/doc/xsl"
    exclude-result-prefixes="xs math xd"
    version="1.0">
    <xd:doc scope="stylesheet">
        <xd:desc>
            <xd:p><xd:b>Created on:</xd:b> Apr 22, 2020</xd:p>
            <xd:p><xd:b>Author:</xd:b> bwb</xd:p>
            <xd:p>Override default text() template by adding a search and replace funtionality</xd:p>
        </xd:desc>
    </xd:doc>

    <xsl:output method="text"/>

    <xd:doc scope="component">
        <xd:desc>The string that should be searched and replaced by $param-replaceString</xd:desc>
    </xd:doc>
    <xsl:param name="param-searchString" select="'&#10;    '"/><!-- actually you also wnat to replace the whitespaces, that's why the searchString looks so  strange -->

    <xd:doc>
        <xd:desc>The string that replace any occurence of $param-searchString</xd:desc>
    </xd:doc>
    <xsl:param name="param-replaceString" select="'\n'"/>

    <xd:doc scope="component">
        <xd:desc>Override for default text() template testing for $param-searchString presence and calling replace template</xd:desc>
    </xd:doc>
    <xsl:template match="text()">
        <xsl:choose>
            <xsl:when test="contains(., $param-searchString)">
                <xsl:call-template name="replace">
                    <xsl:with-param name="InputString" select="."/>
                    <xsl:with-param name="searchString" select="$param-searchString"/>
                    <xsl:with-param name="replaceString" select="$param-replaceString"/>
                </xsl:call-template>
            </xsl:when>
            <xsl:otherwise>
                <xsl:value-of select="."/>
            </xsl:otherwise>
        </xsl:choose>
    </xsl:template>

    <xsl:template name="replace">
        <xsl:param name="InputString"/>
        <xsl:param name="searchString"/>
        <xsl:param name="replaceString"/>

        <xsl:choose>
            <xsl:when test="contains($InputString, $searchString)">
                <xsl:variable name="token-before-first-match" select="substring-before($InputString, $searchString)"/>
                <xsl:variable name="token-after-first-match" select="substring-after(., concat($token-before-first-match, $searchString))"/>
                <xsl:value-of select="concat($token-before-first-match, $replaceString)"/>
                <xsl:choose>
                    <xsl:when test="contains($token-after-first-match, $searchString)">
                        <xsl:call-template name="replace">
                            <xsl:with-param name="InputString" select="$token-after-first-match"/>
                            <xsl:with-param name="searchString" select="$searchString"/>
                            <xsl:with-param name="replaceString" select="$replaceString"/>
                        </xsl:call-template>
                    </xsl:when>
                    <xsl:otherwise>
                        <xsl:value-of select="$token-after-first-match"/>
                    </xsl:otherwise>
                </xsl:choose>
            </xsl:when>
            <xsl:otherwise>
                <xsl:value-of select="$InputString"/>
            </xsl:otherwise>
        </xsl:choose>
    </xsl:template>

</xsl:stylesheet>