Implemented basic external transform function

* "InputXSLT:transform" expects two input arguments and executes the given transformation into the given target file
** this function respresents a important step in the direction of making it possible to write an actual static site generator on top of InputXSLT using XSLT
* added basic "transform" test case
* updated README.md to include this new function

4 files changed, 91 insertions, 0 deletions

diff --git a/test/read_directory/reference.xml b/test/read_directory/reference.xml
index 76fb84f..fedd903 100644
--- a/test/read_directory/reference.xml
+++ b/test/read_directory/reference.xml
@@ -5,6 +5,7 @@
 <item>read_xml_file</item>
 <item>common</item>
 <item>read_file</item>
+<item>transform</item>
 <item>default_params</item>
 </function_read_directory>
 </test_case>
diff --git a/test/transform/reference.xml b/test/transform/reference.xml
new file mode 100644
index 0000000..37c060e
--- /dev/null
+++ b/test/transform/reference.xml
@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<test_case>
+<transform>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
+&lt;xsl:stylesheet
+	version="1.0"
+	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+	xmlns:InputXSLT="function.inputxslt.application"
+	exclude-result-prefixes="InputXSLT"
+&gt;
+
+&lt;xsl:output
+	method="xml"
+	omit-xml-declaration="no"
+	encoding="UTF-8"
+	indent="yes"
+/&gt;
+
+&lt;xsl:template match="/"&gt;
+&lt;test_case&gt;
+	&lt;transform&gt;
+		&lt;xsl:variable
+			name   = "result"
+			select = "InputXSLT:transform('test.xsl', 'test_actual.xml')"
+		/&gt;
+
+		&lt;xsl:value-of select="
+			InputXSLT:read-xml-file('test_actual.xml')/test_case/transform_test
+		"/&gt;
+	&lt;/transform&gt;
+&lt;/test_case&gt;
+&lt;/xsl:template&gt;
+
+&lt;/xsl:stylesheet&gt;
+</transform>
+</test_case>
diff --git a/test/transform/test.xsl b/test/transform/test.xsl
new file mode 100644
index 0000000..40134c4
--- /dev/null
+++ b/test/transform/test.xsl
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xsl:stylesheet
+	version="1.0"
+	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+	xmlns:InputXSLT="function.inputxslt.application"
+	exclude-result-prefixes="InputXSLT"
+>
+
+<xsl:output
+	method="xml"
+	omit-xml-declaration="no"
+	encoding="UTF-8"
+	indent="yes"
+/>
+
+<xsl:template match="/">
+<test_case>
+	<transform_test>
+		<xsl:value-of select="InputXSLT:read-file('transformation.xsl')"/>
+	</transform_test>
+</test_case>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/test/transform/transformation.xsl b/test/transform/transformation.xsl
new file mode 100644
index 0000000..9039642
--- /dev/null
+++ b/test/transform/transformation.xsl
@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xsl:stylesheet
+	version="1.0"
+	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+	xmlns:InputXSLT="function.inputxslt.application"
+	exclude-result-prefixes="InputXSLT"
+>
+
+<xsl:output
+	method="xml"
+	omit-xml-declaration="no"
+	encoding="UTF-8"
+	indent="yes"
+/>
+
+<xsl:template match="/">
+<test_case>
+	<transform>
+		<xsl:variable
+			name   = "result"
+			select = "InputXSLT:transform('test.xsl', 'test_actual.xml')"
+		/>
+
+		<xsl:value-of select="
+			InputXSLT:read-xml-file('test_actual.xml')/test_case/transform_test
+		"/>
+	</transform>
+</test_case>
+</xsl:template>
+
+</xsl:stylesheet>