Revamped external function result trees

* the root node of the result tree of each function is a domain element
** i.e. the root node of "read-xml-file" is "file", the root node of "read-directory" is "directory"
* the root node contains the result state of the function call encoded in a "result" attribute
** possible values are "success" and "error"
** the root node may contain additional attributes such as the target path of a called transformation
* the actual function result is contained within the child nodes of the function root node
** i.e. the XML file tree returned by "read-xml-file" is a child of the function root node
** if specific errors occured they are also returned as child nodes of the function root node
*** this is currently only the case for "transform" where transformation errors are returned as "error" value node childs of the function root node
* updated test cases accordingly

1 files changed, 15 insertions, 4 deletions

diff --git a/test/external_text_formatter/transformation.xsl b/test/external_text_formatter/transformation.xsl
index 00fe3b3..a94f211 100644
--- a/test/external_text_formatter/transformation.xsl
+++ b/test/external_text_formatter/transformation.xsl
@@ -20,13 +20,24 @@
 		)
 	</xsl:variable>
 
-	<xsl:copy-of select="dyn:evaluate($command)/output/*"/>
+	<xsl:copy-of select="dyn:evaluate($command)"/>
 </xsl:template>
 
 <xsl:template name="implementation">
-	<xsl:call-template name="formatter">
-		<xsl:with-param name="source" select="InputXSLT:read-file('test.md')"/>
-	</xsl:call-template>
+	<xsl:variable name="result">
+		<xsl:call-template name="formatter">
+			<xsl:with-param name="source" select="InputXSLT:read-file('test.md')"/>
+		</xsl:call-template>
+	</xsl:variable>
+
+	<xsl:choose>
+		<xsl:when test="xalan:nodeset($result)/output/@result = 'success'">
+			<xsl:copy-of select="xalan:nodeset($result)/output/*"/>
+		</xsl:when>
+		<xsl:otherwise>
+			Failure during external text formatting
+		</xsl:otherwise>
+	</xsl:choose>
 </xsl:template>
 
 </xsl:stylesheet>