--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xslt/preprocess.xsl	Sun Feb 25 17:12:33 2018 +0300
@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="utf-8"?>
+<xsl:stylesheet version="1.0"
+	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+	xmlns:m="http://implab.org/schemas/data-model.v1.xsd"
+	xmlns:exsl="http://exslt.org/common"
+	xmlns:t="http://implab.org/schemas/temp"
+>
+	<!--
+	This template provides 'module' variable which is the
+	result of processing imports from packages.
+	
+	Variable $module is a node set created from the result-tree
+	which is the result of applying templates in mode=preprocess  
+	-->
+	<xsl:output method="xml" indent="yes" />
+	<xsl:variable name="preprocessResult">
+		<t:module>
+			<xsl:call-template name="preprocess" />
+		</t:module>
+	</xsl:variable>
+	<xsl:variable name="module" select="exsl:node-set($preprocessResult)/t:module"/>
+
+	<xsl:template name="preprocess">
+		<xsl:param name="root" select="/" />
+		<xsl:param name="pending" select="$root/m:package/m:import[@href]" />
+		<xsl:param name="seen" select="/.." />
+		<xsl:param name="file" select="''" />
+		<xsl:param name="primary" select="true()" />
+
+		<xsl:if test="not($seen[generate-id() = generate-id($root)])">
+			<xsl:apply-templates select="$root" mode="preprocess">
+				<xsl:with-param name="primary" select="$primary" />
+				<xsl:with-param name="file" select="$file" />
+			</xsl:apply-templates>
+			<xsl:if test="$pending">
+				<xsl:variable name="doc" select="document($pending[1]/@href)" />
+				<xsl:call-template name="preprocess">
+					<xsl:with-param name="root" select="$doc" />
+					<xsl:with-param name="file" select="$pending[1]/@href" />
+					<xsl:with-param name="pending"
+						select="$pending[position() > 1] | $doc/m:package/m:import[@href]" />
+					<xsl:with-param name="seen" select="$root | $seen" />
+					<xsl:with-param name="primary" select="false()" />
+				</xsl:call-template>
+			</xsl:if>
+		</xsl:if>
+	</xsl:template>
+
+	<xsl:template match="m:package" mode="preprocess">
+		<xsl:param name="primary" />
+		<xsl:param name="file" />
+		<xsl:copy>
+			<xsl:copy-of select="@*" />
+			<xsl:if test="$primary">
+				<xsl:attribute name="primary"><xsl:value-of select="$primary" /></xsl:attribute>
+			</xsl:if>
+			<xsl:if test="$file">
+				<xsl:attribute name="file"><xsl:value-of select="$file" /></xsl:attribute>
+			</xsl:if>
+			<xsl:apply-templates mode="preprocess">
+				<xsl:with-param name="primary" select="$primary" />
+				<xsl:with-param name="file" select="$file" />
+			</xsl:apply-templates>
+		</xsl:copy>
+	</xsl:template>
+
+	<xsl:template match="*|/" mode="preprocess">
+		<xsl:param name="primary" />
+		<xsl:param name="file" />
+		<xsl:copy>
+			<xsl:copy-of select="@*" />
+			<xsl:apply-templates mode="preprocess">
+				<xsl:with-param name="primary" select="$primary" />
+				<xsl:with-param name="file" select="$file" />
+			</xsl:apply-templates>
+		</xsl:copy>
+	</xsl:template>
+</xsl:stylesheet>
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