Epub Sample
< Epub
Creating an ebook with ConTeXt is still tedious and needs a lot of manual work - that will not change, since everyone has other needs, uses different structures etc. Here I’ll show you my workflow for creating ebooks of my songbooklets (that use LilyPond via filter module for the notes).
I’m using ConTeXt’s Project structure, separating content in products (for me: single booklets) and components (for me: single songs) with a common stylesheet (environment). Unfortunately, ConTeXt has a bug in XML creation in this setup.
Contents
ConTeXt setup
In your environment or product, you need these settings (perhaps not all of them):
\setupexport[hyphen=yes, %firstpage={cover.jpg}, % is ignored title={Songbook}, subtitle={}, author={Hraban} ] \setupbackend[export=export.xml] \settaggedmetadata[ % here you can set as many metadata entries as you like %firstpage={cover.jpg}, % is ignored title={Songbook}, name=ebook, % this becomes the name of the output directory author={Hraban}, subtitle={} version={\expand\currentdate}] % doesn’t work \setupinteraction[state=start, color=,contrastcolor=, % these settings are for PDF metadata title={Songbook}, subtitle={}, keywords={}, author={Hraban}]
Make sure to tag all your structural elements with \start...-\stop..., e.g. \startchapter, but even \startparagraph!
Then you can call ConTeXt and its ePub script:
context mysongbook
mtxrun --script epub --make mysongbook
The first creates export.xml and a bunch of other files. The second creates a directory "ebook.tree" with the proper structure for ePub. The ePub file in the tree directory is unusable.
We’ll mostly work with "export.xml" that contains all your content (check that, you’ll miss everything that was not properly tagged).
Fix export.xml
If you run the epub script on a single file, you’ll get a well-formed and usable export.xml. If you use a project structure, the root node <document> is missing. Just put it in manually (after the comment lines). You can also move the <metadata> block out of the first structure, but that’s merely a cosmetical error.
A proper export.xml starts like this:
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!-- input filename : solo -->
<!-- processing date : Wed Aug 27 13:47:46 2014 -->
<!-- context version : 2014.08.21 09:56 -->
<!-- exporter version : 0.31 -->
<document language="en" file="solo" date="Wed Aug 27 13:47:46 2014" context="2014.08.21 09:56" version="0.31" xmlns:m="http://www.w3.org/1998/Math/MathML">
<metadata>
<metavariable name="author">Hraban</metavariable>
</metadata>
<section detail="chapter" location="aut:1">
...
You don’t need the attributes of the document node, even if we could use the language setting.
Transform XML to HTML etc.
Even if the ePub format is supposed to work with any XML, most readers only accept HTML. I use the free version of [Saxon] and some XSL transformations for the conversion.
The incantation goes like saxon -o:content.xhtml -s:export.xml -xsl:export2html.xsl.
I installed Saxon on my Mac with MacPorts, then instead of just "saxon" you must call java -jar /opt/local/share/java/saxon9he.jar.
This is my **export2html.xsl**:
<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet version= "2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output
method="xml"
encoding="utf-8"
indent="yes"
omit-xml-declaration="yes"
/>
<xsl:variable name="within-paragraph">0</xsl:variable >
<xsl:template match="/">
<html>
<head>
<meta charset="utf-8" />
<title><xsl:value-of select='//metavariable[@name="title"]'/> </title>
<xsl:for-each select="//metavariable">
<meta>
<xsl:attribute name="name">
<xsl:value-of select="@name"/>
</xsl:attribute>
<xsl:attribute name="content">
<xsl:apply-templates/>
</xsl:attribute>
</meta>
</xsl:for-each>
<link rel="stylesheet" href="style.css" type="text/css" ></link>
<link rel="stylesheet" href="Styles/style.css" type="text/css" ></link>
</head>
<body lang="de">
<xsl:value-of select='//metavariable[@name="title"]'/>
<xsl:value-of select='//metavariable[@name="subtitle"]'/>
<xsl:apply-templates/>
</body>
</html>
</xsl:template>
<xsl:template match="metadata">
</xsl:template>
<xsl:template match="section">
<a name="{translate(@location,':','_')}"/>
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="sectiontitle">
<xsl:choose>
<xsl:when test="../@detail='part'">
<xsl:apply-templates/>
</xsl:when>
<xsl:when test="../@detail='chapter'">
<xsl:apply-templates/>
</xsl:when>
<xsl:when test="../@detail='section'">
<xsl:apply-templates/>
</xsl:when>
<xsl:when test="../@detail='subsection'">
<xsl:apply-templates/>
</xsl:when>
<xsl:otherwise>
<xsl:apply-templates/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
<xsl:template match="sectioncontent">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="externalfilter">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="lines">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="line">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="list">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="listitem">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="listcontent">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="listpage">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="break">
<xsl:if test="within-paragraph = 0">
<xsl:text disable-output-escaping="yes"><![CDATA[
]]></xsl:text>
</xsl:if>
<xsl:if test="within-paragraph > 0">
</xsl:if>
</xsl:template>
<xsl:template match="paragraph">
<xsl:variable name="within-paragraph">1</xsl:variable >
<xsl:apply-templates/>
<xsl:variable name="within-paragraph">0</xsl:variable >
</xsl:template>
<xsl:template match="delimited">
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="highlight">
<xsl:if test="@detail = 'emph'">
<xsl:apply-templates/>
</xsl:if>
</xsl:template>
<xsl:template match="image">
<img src="Images/{substring-after(@name,'prd_songbook-temp-lilypond-')}.png" id="{@id}" alt="{@name}" />
</xsl:template>
<xsl:template match="link">
<a href="#{@location}" title="{@destination}"><xsl:apply-templates/></a>
</xsl:template>
</xsl:stylesheet>
