Here’s what I think are the key differentiators for which process to use and why: if you need to change the XML structure itself as it is being imported or exported into InDesign, use XSL transforms. I provide some examples later in this book. InDesign has its limitations in transforming XML on import and export; the trick is to know when to “speak InDesign” and how.

If you need to use InDesign to handle tasks that are inherent to InDesign itself, such as Map Tags to Styles, you could use the XML scripting capabilities. Figure 10-1 lists some of the available scripts.

Figure 10-1. InDesign XML scripts

If you want to try more advanced automation, there are scripts for what Adobe terms “rules-based XML publishing” (Figure 10-2).

Figure 10-2. InDesign XML rules scripts

The rules are intended for the high-end publishing workflows used by magazine, catalog, and newspaper publishers. They are not shipped with the regular distribution of scripts in the InDesign Scripts folder. You may have to contact someone via the forums to get these scripts now.

It’s beyond the scope of a small book such as this to explore scripting and XML rules. Take a look at books such as Grant Gamble’s InDesign CS5 Automation Using XML & JavaScript or Shirley W. Hopkins’s AppleScripting Adobe InDesign CS5 and CS5.5 (both published through Createspace, 2011).

Now, on to what you might want to do with XML in InDesign using XSLT.

Sometimes, you know that there is content inside the main XML document that you would like to use for another purpose. The most common alternative purpose is something like making a list of figures or a table of contents from captions and titles in the XML file. But you can be more creative. Perhaps you need to find all of the keywords that were tagged in an XML file and extract them to build the foundations for a glossary XML file. Here is some XML content with keywords:

    <Story name="Residency Requirements">
        <SectionHead>Residency Requirements</SectionHead>
        <para>New York State law requires that all students  file proof of 
               residence each academic year. For New York State residents, 
               the proper form should be submitted upon registration. 
               Until you comply with this requirement, you will be billed the
               <keyword>non-resident tuition rate</keyword> (twice the resident 
               rate).
         </para>
        <topic title="Residents of Monroe County">
            <SubHeads>Residents of Monroe County</SubHeads>
            <para>If you have been a permanent legal resident of New York State
                  for the past year, and a resident of Monroe County for the 
                  last six months,complete a Residency Certificate
                  <keyword>Affidavit</keyword>, sign it, and submit it 
                  with your registration.
         </para>
        </topic> ...
    </Story>

An XSL transform can be pretty simple:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="no"/>
    <xsl:template match="/">
        <!-- make a new root element for the glossary XML -->
        <xsl:element name="glossary">
            <xsl:for-each select="//keyword">
                <!-- make an element for the term -->
                <xsl:element name="term">Term: <xsl:value-of select="."/>
                </xsl:element>
                <!-- make an element for the definition -->
                <xsl:element name="definition">Definition: </xsl:element>
            </xsl:for-each>
        </xsl:element>
    </xsl:template>
</xsl:stylesheet>

The results will be very useful: a new glossary XML file, with keywords as terms, and a blank definition element following each term, ready for an author to work on. Because the keywords were in the source XML and they are all now terms in the output XML, the transform makes it easy to correlate the glossary to the document that contains the keywords by filling in the definition:

<?xml version="1.0" encoding="UTF-8"?>
<glossary>
    <term>Term: non-resident tuition rate</term>
    <definition>Definition: </definition>
    <term>Term: Affidavit</term>
    <definition>Definition: </definition>
</glossary>

This type of XSL seems to work well on an existing InDesign file tagged with keywords. Upon export, if the XSL is used, the resulting file will just be the glossary XML, which you can put in a document of its own or into sidebars in a separate text flow in the same document as the original XML.

Alternatively, you could export the entire document XML and then apply the transform to the exported XML (using an XSLT processor such as Oxygen or XMLSpy) to get your starting glossary XML file.

One of the common things that people who work with XML do is to sort XML content based on values of attributes on XML elements, or according to the text contained in the elements. Sorting is useful for tables of data, but sometimes it is used for blocks of content like glossaries or directory listings. For example, with this XML:

<?xml version="1.0" encoding="UTF-8"?>
<glossary>
    <term>Affidavit</term>
    <definition>A legal document that provides proof (of residency, payment, 
    status as an emancipated minor, etc.). Affidavits must be prepared by an 
    attorney, appropriate agency or counselor, and must be attested to under 
    supplied with a notarization stamp.</definition>
    <term>F-1 Visa</term>
    <definition>An F-1visa is a nonimmigrant visa issued by the USCIS (formerly 
    INS) to the alien student who is pursuing studies in the US. The "F" visa 
    is reserved for nonimmigrants wishing to pursue academic studies and/or 
    language training programs.</definition>
    <term>INS documentation</term>
    <definition>Written materials provided by US Citizen and Immigration 
    Services (formerly Immigration and Naturalization Services) to prove a 
    student's status as an legal nonimmigrant.</definition>
    <term>Non-resident tuition rate</term>
    <definition>Students whose primary residence is not in the state will pay 
    the tuition rate for non-residents. However, if a student resides within 
    the state for the six months of the year immediately preceding the start
    of the session for which tuition is paid, the student qualifies for the 
    resident tuition rate.</definition>
    <term>EDU-PAY</term>
    <definition>A payment plan for students who do not have the resources to 
    pay the bill in full or who may not qualify for sufficient financial aid 
    to cover the entire bill at the college.</definition>
</glossary>

you can use this XSL to write a top-level <glossary> element containing terms and definitions sorted in ascending alphabetical order:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" version="1.0" encoding="UTF-8"/>
    <xsl:template match="/">
        <xsl:element name="glossary">
            <xsl:for-each select="glossary/term">
              <xsl:sort order="ascending"/>
              <xsl:copy-of select="."/>
            <xsl:copy-of select="following-sibling::definition[1]"/>
            </xsl:for-each>
        </xsl:element>
    </xsl:template>
</xsl:stylesheet>

This is the resulting XML; the definition for EDU-PAY is now near the top of the list of terms instead of at the end.

<glossary>
    <term>Affidavit</term>
    <definition>A legal document that provides proof (of residency, payment, 
    status as an emancipated minor, etc.). Affidavits must be prepared by an 
    attorney, appropriate agency or counselor, and must be attested to under 
    supplied with a notarization stamp.</definition>
    <term>EDU-PAY</term>
    <definition>A payment plan for students who do not have the resources to 
    pay the bill in full or who may not qualify for sufficient financial aid 
    to cover the entire bill at the college.</definition>
    <term>F-1 Visa</term>
    <definition>An F-1visa is a nonimmigrant visa issued by the USCIS (formerly 
    INS) to the alien student who is pursuing studies in the US. The "F" visa 
    is reserved for nonimmigrants wishing to pursue academic studies and/or 
    language training programs.</definition>
    <term>INS documentation</term>
    <definition>Written materials provided by US Citizen and Immigration 
    Services (formerly Immigration and Naturalization Services) to prove a 
    student's status as an legal nonimmigrant.</definition>
    <term>Non-resident tuition rate</term>
    <definition>Students whose primary residence is not in the state will pay 
    the tuition rate for non-residents. However, if a student resides within 
    the state for the six months of the year immediately preceding the start
    of the session for which tuition is paid, the student qualifies for the 
    resident tuition rate.</definition>
</glossary>

You can apply sorts that create descending order by using xsl:sort order="descending" on the elements you are looping over with the <xsl:for-each>. For more about loops and sorts, see http://www.w3schools.com/xsl/el_sort.asp.

To sort before importing XML into InDesign, apply the sorting transform, and then import the resulting XML output.

Excluding some of the elements can be accomplished with placeholders and the XML import option “Only import text elements that match existing structure” (see Understanding InDesign’s XML Import Options), but you might want to remove entire sets of elements, or only selected ones, on your way in or out of InDesign.

For example, let’s suppose that you have product catalog XML that contains <price> elements that have both <unit> and <bulk> elements.^[5] You produce two catalogs: one for wholesalers and one for consumers. You might use the same XML file for each catalog but suppress whichever price that doesn’t apply in each catalog version.

Your XSL transform would look for the type of price you want in the catalog and copy only those products for import. This is the tiny example XML file, in which one element has a bulk price:

<?xml version="1.0" encoding="UTF-8"?>
<!-- <?xml-stylesheet type="text/xsl" href="bulkPrice.xsl"?> -->
<products>
    <product type="petToy">
        <name>Chewy Toy</name>
        <catno>D123</catno>
        <price currency="USD">
            <bulk qty="100">.39</bulk>
            <unit qty="1">.99</unit>
        </price>
        <unit pack="recyled" measure="imperial">4 oz.</unit>
        <description>Delicious enviro-friendly dog treat made with processed pig
         parts, shaped like a miniature pig.</description>
    </product>
    <product type="petToy">
        <name>Squeaky Toy</name>
        <catno>D456</catno>
        <price currency="USD">
            <unit qty="1">1.49</unit>
        </price>
        <unit pack="recyled" measure="imperial">5.1 oz.</unit>
        <description>Exciting enviro-friendly dog toy made with recycled,
         nontoxic, heavy-duty plastics. Squeak is air-produced, no hard parts
         inside. Safe for all mature dogs over 10 lbs. Not recommended for 
         puppies and smaller dogs.</description>
    </product>
</products>

And here is a small XSL file that looks for a bulk price and copies only <product> elements that have one:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" version="1.0" standalone="yes"/>
    <xsl:template match="/">
        <xsl:apply-templates select="products"/>
    </xsl:template>
    <xsl:template match="products">
        <xsl:copy-of select="product[price/bulk !='']"/>
    </xsl:template>
</xsl:stylesheet>

The previous example XSL produces this XML output:

<?xml version="1.0" encoding="UTF-16" standalone="yes"?>
<product type="petToy">
    <name>Chewy Toy</name>
    <catno>D123</catno>
    <price currency="USD">
        <bulk qty="100">.39</bulk>
        <unit qty="1">.99</unit>
    </price>
    <unit pack="recyled" measure="imperial">4 oz.</unit>
    <description>Delicious enviro-friendly dog treat made with processed pig
    parts, shaped like a miniature pig.</description>
</product>

In the previous example, the Squeaky Toy item was excluded because it doesn’t have a bulk price. When the XML is imported into the wholesale catalog with the XSLT applied during import, the catalog content will be pertinent to the wholesale audience.

Alternately, you could process the original XML with XSL as a separate step before importing the XML into InDesign.

Sometimes you need to make a wrapper around part of the incoming XML to use the functions of InDesign placeholders or tables. With XSL, you can add an element to the original XML structure. Suppose you have a set of fairly complex elements that belong together, but they are just strung along one after another. In InDesign, you want to put each set into its own separate text flow. Here’s an example of how you could make this happen with our previous glossary XML example:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="no"/>
    <xsl:template match="/">
        <xsl:element name="glossary">
            <xsl:for-each select="glossary/term">
                <!-- start the wrapper element inside the for-each loop so it
                   will make a wrapper for each term and definition pair -->
                <xsl:element name="glossTerm">
                    <xsl:copy-of select="."/>
                    <xsl:copy-of select="following-sibling::definition[1]"/>
                </xsl:element>
                <!-- end the wrapper element-->
            </xsl:for-each>
        </xsl:element>
    </xsl:template>
</xsl:stylesheet>

The resulting XML has a wrapper around each term and definition pair:

<?xml version="1.0" encoding="UTF-16"?>
<glossary>
    <glossTerm>
        <term>Affidavit</term>
        <definition>A legal document that provides proof (of residency, payment,
        status as an emancipated minor, etc.). Affidavits must be prepared by 
        an attorney, appropriate agency or counselor, and must be attested to 
        under supplied with a notarization stamp.</definition>
    </glossTerm>
    <glossTerm>
        <term>F-1 Visa</term>
        <definition>An F-1visa is a nonimmigrant visa issued by the USCIS
         (formerly INS) to the alien student who is pursuing studies in the US.
         The "F" visa is reserved for nonimmigrants wishing to pursue academic 
         studies and/or language training programs.</definition>
    </glossTerm>
    <glossTerm>
        <term>INS documentation</term>
        <definition>Written materials provided by US Citizen and Immigration
         Services (formerly Immigration and Naturalization Services) to prove a 
         student's status as an legal nonimmigrant.</definition>
    </glossTerm>
    <glossTerm>
        <term>Non-resident tuition rate</term>
        <definition>Students whose primary residence is not in the state will
         pay the tuition rate for non-residents. However, if a student resides
         within the state for the six months of the year immediately preceding
         the start of the session for which tuition is paid, the student 
         qualifies for the resident tuition rate.</definition>
    </glossTerm>
    <glossTerm>
        <term>EDU-PAY</term>
        <definition>A payment plan for students who do not have the
         resources to pay the bill in full or who may not qualify for sufficient
         financial aid to cover the entire bill at the college.</definition>
    </glossTerm>
</glossary>

If you have a text frame for each glossTerm, you can drag each of the terms into its text frame. Or you can create a glossary as a text flow tagged as <glossary> that you set up previously for repeating block placeholder elements structured like this: an element called <glossTerm>, containing the <term> element, followed by a manual line break, then a tab and a <definition> element, followed by a paragraph break. See Figure 10-3.

Figure 10-3. Placeholders (shown in Story Editor view) including the wrapper element that will be created with the XSLT

The <term> and <definition> elements are mapped to character styles to make them bold and italic, respectively. The <glossTerm> element is mapped to a Basic Paragraph style.

The XML Import Options dialog should look like Figure 10-4, pointing to the XSLT. The results will look like Figure 10-5 in InDesign.

Figure 10-4. Apply XSLT to create wrappers on import

Figure 10-5. Example of creating wrapper elements with XSLT on import with placeholders for repeating blocks of content

By extrapolation, any time you need to make a repeating block, the same XSLT technique can be used to develop richer XML with the required wrapper elements.

Let’s use the same kind of concept to make an InDesign table from our incoming XML. In this example, suppose that we do not want to have <Table> and <Cell> elements in our source XML because it violates our DTD. We can add the table markup solely within InDesign and keep our XML source pure. We will use XSLT upon import into InDesign.

We’ll go back to the InDesign placeholder concept first and make a table that looks like what we want to generate (this is always the best practice if you need to make tables from XML in InDesign). Our simple table looks like Figure 10-6: the table is tagged as <glossary> and consists of a header row containing two cells tagged as <colHead> elements and another row containing one cell tagged as <term> and one tagged as <definition>.

Figure 10-6. Tagged table placeholder for the glossary

Now we can use this XSLT upon import by selecting it in the Import XML dialog using the Apply XSLT option:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:template match="/">
        <xsl:element name="glossary">
            <xsl:for-each select="glossary/term">
                <!-- start the wrapper element inside the for-each loop so it
                   will make a wrapper for each term and definition pair -->
                <xsl:element name="glossTerm">
                    <xsl:copy-of select="."/>
                    <xsl:copy-of select="following-sibling::definition[1]"/>
                </xsl:element>
                <!-- end the wrapper element-->
            </xsl:for-each>
        </xsl:element>
    </xsl:template>
</xsl:stylesheet>

By applying the XSLT on the glossary XML, we get the table shown in Figure 10-7 in InDesign.

Figure 10-7. Table with multiple rows created by importing XML into InDesign with XSLT

If you set up the table with heading rows, they will repeat when the table flows from one text frame to another. If you use the alternate row coloring, you can achieve a look like Figure 10-8.

Figure 10-8. Imported table flowed into multiple text frames with alternating color

See the InDesign Help section on tables for more information on creating the look you want in your table layout.

In XSLT, changing simple XML or HTML to a more complex XML form is upcasting and changing XML to a simpler DTD is downcasting.

It may be that you need to convert HTML content into some form of XML. The simplest way to do this is to save your HTML as XHTML, a form of HTML that conforms to XML rules. Once it has been cleaned up as XHTML, you need to change the file extension to .xml before you import it into InDesign.

It is possible to import the XHTML file without any transformation, but we want to modify the incoming XML somewhat to make it more compatible with our InDesign layout. We will model the XHTML elements that correspond to the InDesign tagging concepts. We don’t necessarily need the <head> element, because it is used only for the HTML title bar and metadata, not for anything that we will print. So we can make a structure like Figure 10-9 in InDesign.

Figure 10-9. Placeholder for XHTML import

Remember that you can use XSLT to change the order of elements (such as sorting alphabetically), but this step is best done as a preprocessing step before importing XML, rather than using the Apply XSLT option.

To make the XHTML <table> element, which is always a lowercase word, match to InDesign’s internal tag <Table>), which is always uppercase, we will use the Tagging Presets dialog on the Tags panel (see Figure 10-10). We also want the <td> element to map to the InDesign <Cell>.

Figure 10-10. The Tagging Preset Options of the Tags panel, setting Tables and Table Cells to <table> and <td> elements

In my tests, I used a simple XHTML file that looked like this:

<?xml version="1.0" encoding="UTF-8"?>
<!-- <?xml-stylesheet type="text/xsl" href="xmlizeXHTML.xslt"?> -->
<html>
    <head>
        <title>XHTML example</title>
    </head>
    <body>
        <h1>An example of XHTML</h1>
        <p>Some general rules for XHTML are</p>
        <ul>
            <li>Every start tag must have a matching end tag</li>
            <li>All tag pairs must end without crossing over other end tags
                  (to create properly nested structures)</li>            <li>Tag names cannot start with a number, and they cannot include
                  any spaces, or "illegal" characters, such as  ? and /, which 
                  can be confused with parts of the markup and processing 
                  instructions.</li>
        </ul>
        <table border="1">
            <tbody>
                <tr><th>a table header (th)</th></tr>
                <tr><td>a table cell (td)</td></tr>
            </tbody>
        </table>
    </body>
</html>

The XSLT that we will use to simplify the XHTML looks like this (although this example is not developed to handle all possible XHTML elements):

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
    <xsl:template match="/">
        <xsl:apply-templates select="html/body"></xsl:apply-templates>
    </xsl:template>
    <xsl:template match="html/body">
    <xsl:element name="body"><xsl:apply-templates/></xsl:element>
    </xsl:template>
    <!-- copy some elements directly -->
    <xsl:template match="h1|h2|h3|h4|h5|h6|p|ul|ol"><xsl:copy-of select="."/>
    </xsl:template>
    <!-- simplify the table structure to what InDesign uses, 
       no tbody or tr elements needed -->
    <xsl:template match="table">
        <xsl:element name="Table"><xsl:apply-templates/></xsl:element>
    </xsl:template>
    <xsl:template match="tbody"><xsl:apply-templates select="tr"/>
    </xsl:template>
    <xsl:template match="tr"><xsl:apply-templates select="th|td"/>
    </xsl:template>
    <xsl:template match="th"><xsl:element name="Cell"><xsl:apply-templates/>
    </xsl:element>
    </xsl:template>
    <xsl:template match="td"><xsl:copy-of select="."/></xsl:template>
    <xsl:template match="img">
        <xsl:element name="Image"><xsl:attribute name="href">
         <xsl:value-of select="@href"/></xsl:attribute></xsl:element>
    </xsl:template>
    <!-- exclude the head tag content -->
    <xsl:template match="html/head"/>
</xsl:stylesheet>

We can import the XML and apply the XSLT to it as it comes in. Doing so will strip off the unnecessary <head> element and simplify the <table> by removing the <tbody> and <tr> tags. Select the <body> placeholder element in the structure view and use File→Import XML, then select the XHTML file that you saved with a .xml extension.

The settings for the XML Import Options dialog will be: Apply XSLT, “Clone repeating text elements” (for the ul/li structure), “Only import elements that match existing structure” (it is important to check this), and “Do not import contents of whitespace-only elements”; see Figure 10-11.

Figure 10-11. Settings for the XML Import Options dialog for the XHTML-as-XML import

The results, after some tinkering with the Paragraph styles, are shown in Figure 10-12.

Figure 10-12. XHTML imported into InDesign and formatted with matching paragraph and character styles

You can extend this concept to all the tags in the official XHTML DTD, if you wish. Generally, you would want to use XSLT for the following tasks:

In some cases (although who would ever want to do this?), you might want to save some XML in InDesign as web page content that matches a particular CSS. You can do this by saving the content with an XSLT written to downcast the XML structure to standard HTML tags. (See also the section Exporting XHTML When XML is in Your InDesign File.) Let’s try the XSLT export to HTML with the course descriptions that we have worked with earlier.

First, we must decide what the output for the HTML will be. We’ll assume that we have a CSS already set up for displaying the course descriptions online. To make it simple to understand, the CSS classes have names that correlate to the XML elements.

We are going to create a new XHTML output from the course content using a series of steps. We can use the same tags that we created for the XHTML example for this example. We already have a simple tagged file with <h1>, <p>, <ul>, <li>, <p>, and <code> elements in a <body> element, which we can export to get an idea of the result file that we want. Select the XML in the Structure pane, then right-click to get the Structure menu and select Export XML. In the export dialog, use the settings in Figure 10-13.

Figure 10-13. The Export XML dialog with options set to make quasi-XHTML output

After you export, change the file extension of the exported file from .xml to .html and see how it looks in your browser; see Figure 10-14. (For our example, which did not have a <head> element, you must edit the output file if you want to make it conform to the HTML strict DTD. See http://www.w3schools.com/ for good tutorials on XHTML.)

Figure 10-14. The XHTML export (cleaned to conform to the HTML strict DTD)

Compare the course content to the HTML tags to see how you might want to tag the final output. For example, you might want to output the element <CourseDescriptions_Major> as an <h1 class="major">, and the <CourseDescription_Name> as an <h2 class="coursename">, the <CourseDescription_Text> as <p class="coursedescription">, and the prerequisite <CourseDescription_Note> as <p class="coursenote">. The semantically meaningful CSS class names will help make apparent the subject of the content and its origin.

This is the sample XML:

<CourseDescriptions>
    <CourseDescription_Major>Accounting</CourseDescription_Major>
    <CourseDescription>
        <CourseDescription_Name>ACC 101&#9;Accounting Principles I&#9;4 Credits
         </CourseDescription_Name>
        <CourseDescription_Text>Basic principles of financial accounting for
          the business enterprise with emphasis on the valuation of business 
          assets, measurement of net income, and double-entry techniques for 
          recording transactions.  Introduction to the cycle of accounting
          work, preparation of financial statements, and adjusting and closing 
          procedures.  Four class hours.</CourseDescription_Text>
        <CourseDescription_Footnote type="prereq">
          Prerequisite: MTH 098 or MTH 130 or equivalent.
        </CourseDescription_Footnote>
    </CourseDescription>
...
    <CourseDescription_Major>Art</CourseDescription_Major>
    <CourseDescription>
        <CourseDescription_Name>ART 101    Art Essentials    3 Credits
          </CourseDescription_Name>
        <CourseDescription_Text>This course is designed to improve the student's
          visual perception and expand critical awareness through a variety of 
          hands-on studio projects. The student will become familiar with the 
          methods, materials, media, vocabulary, and techniques of making art. 
          This course is suggested for students who are interested in  
          developing their creative skills but are not art majors. 
          Two class hours, two studio hours. (SUNY-A)
        </CourseDescription_Text>
    </CourseDescription>
</CourseDescriptions>

The XSL transform could accomplish these XML to HTML changes: generate a valid <html> with <head>, <title> <link> (for the CSS file) and <body>, and then make the individual heading levels with the CSS classes and even some IDs. Example 10-1 is a simple XSLT example without any loops.

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="html" encoding="utf-8"/>
    <xsl:template match="/">
        <html>
            <head>
                <title>Course descriptions web version</title>
                <link rel="stylesheet" href="courses.css"    type="text/css"></link>
            </head>
            <body>
                <xsl:apply-templates/>
            </body>
        </html>
    </xsl:template>
    <xsl:template match="CourseDescriptions">
        <h1>Course Descriptions</h1>
        <xsl:apply-templates/>
    </xsl:template>
    <xsl:template match="CourseDescription">
        <div>
            <xsl:attribute name="id">
              <xsl:value-of select="substring(CourseDescription_Name,1,7)"/>
              <xsl:apply-templates/></xsl:attribute>
            <xsl:apply-templates/>
        </div>
    </xsl:template>
    <xsl:template match="CourseDescription_Major">
        <hr/>
        <div class="major">
            <xsl:attribute name="id"><xsl:value-of select="."/></xsl:attribute>
            <h2 class="major">
                <xsl:value-of select="."/>
            </h2>
        </div>
    </xsl:template>
    <xsl:template match="CourseDescription_Name">
        <h3 class="coursename">
            <xsl:value-of select="."/>
        </h3>
    </xsl:template>
    <xsl:template match="CourseDescription_Text">
        <p class="coursedescription">
            <xsl:value-of select="."/>
        </p>
    </xsl:template>
    <xsl:template match="CourseDescription_Footnote">
        <p class="coursenote">
            <xsl:text>Notes: </xsl:text><br/>
            <xsl:value-of select="."/>
        </p>
    </xsl:template>
</xsl:stylesheet>

The CSS has only a few classes in it:

body
{background-color: #ffffff;}
h1, h2, h3 {font-family: Verdana, Arial, sans-serif;;margin-bottom:6px}
.major {color:green; font-size: 19px;margin-bottom:0px}
.coursename {color:navy; font-size: 13px;margin-bottom:0px}
p {font-family: Arial, Verdana, sans-serif; font-style:normal; font-size: 13px}
.coursedescription {font-style:normal;color:#000000;margin:0px 0px 0px 0px}
.coursenote {font-style:italic;color:#333333;margin: 0px 10px 20px 20px}

The HTML output looks like Figure 10-15 (viewed in the browser to see the CSS applied).

Figure 10-15. XHTML created from XML exported using Apply XSLT to add CSS styles

Notice that the course numbers have been used to generate unique IDs for the <div>s containing course descriptions:

<html>
<head>
    <META http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Course descriptions web version</title>
    <link rel="stylesheet" href="courses.css" type="text/css" />
</head>
<body>
    <h1>Course Descriptions</h1>
    <hr>
    <div class="major" id="Accounting">
    <h2 class="major">Accounting</h2>
    </div>
    <div id="ACC 101">
    <h3 class="coursename">ACC 101&#9;Accounting Principles I&#9;4 Credits</h3>
    <p class="coursedescription">Basic principles of financial accounting for  
        the business enterprise with emphasis on the valuation of business 
        assets, measurement of net income, and double-entry techniques for 
        recording transactions. Introduction to the cycle of accounting work, 
        preparation of financial statements, and adjusting and closing 
        procedures. Four class hours.</p>
    <p class="coursenote">Notes: <br>Prerequisite: MTH 098 or MTH 130 
    or equivalent.</p>
    </div>
    ...more
    <hr>
    <div class="major" id="Art">
    <h2 class="major">Art</h2>
    </div>
    <div id="ART 101">
    <h3 class="coursename">ART 101    Art Essentials    3 Credits</h3>
    <p class="coursedescription">This course is designed to improve the 
        student's visual perception and expand critical awareness through a 
        variety of hands-on studio projects. The student will become familiar
        with the methods, materials, media, vocabulary, and techniques of making
        art. This course is suggested for students who are interested in
        developing their creative skills but are not art majors.  Two class
        hours, two studio hours. (SUNY-A)</p>
    </div>
</body>
</html>

Have you noticed that I haven’t mentioned anything about links in my discussion of generating XHTML with XSLT? Adobe has enabled an auto-generation of hyperlinks in InDesign (if you use the Cross Media Export→Export to XHTML, I believe the <a> tag will be created from a hyperlink you have created with a URL). But, if you are writing your own XSLT, there is no built-in method to get the <a> tag in the Export XML output. The most straightforward way to handle it is to create a standard web <a> tag in your content, give it an href attribute, and export it.

If your current InDesign XML tag set doesn’t include the <a> tag, you can add it to the list of tags. In the Tags window, select New tag, then overtype the highlighted tag name in the window with “a”. Switch to the Text Selection tool, select the text you want to use for your link, and tag it by clicking the new <a> tag name in the Tags list.

You must add the required href attribute to the <a>-tagged text. With the tagged text selected in the Structure pane, click the round black button in the top of the Structure window. When the Add Attribute window opens, type “href ” (without quotes) in the name text box and the destination URL in the value text box.

To get this element in your export when you are using Apply XSLT, include a small template that copies the <a> tag, including its attribute:

<xsl:template match="a"><xsl:copy-of select="."/></xsl:template>

With XSLT, you can also rewrite an existing element such as <link> to an <a> element with an empty @href attribute. Then you can edit the @href in an HTML editor to insert the correct link path and file name. More advanced XSLT can use automation to pass in a relative path to a known website location and prepend it into the @href value. For example, you can have a parameter in your XSLT, $mysite, defined as http://www.mysite.com/, then insert that as the starting part of every @href. Then all you would have to do is add the correct filename for the .html page or other resources that your @href points to.

Attributes are little descriptive bits of information used by programs and people to find and manipulate items in XML files. You can add attributes to indicate:

Generally, it is easier to add attributes with XSLT than within InDesign if you want to use them all over your XML, but Adobe gives you a tool to add an attribute manually, so we’ll start with that.

Select an XML element in the Structure pane, then click the big black dot in the top icon bar of the Structure pane (or right-click and select New Attribute from the Structure menu). In the New Attribute dialog, enter the name of the attribute and the value (Figure 10-16).

Figure 10-16. The New Attribute dialog used to add the lang attribute

<xsl:attribute name="attname">attvalue</xsl:attribute>

<xsl:template match="CourseDescription">
        <div>
            <xsl:attribute name="id"><xsl:value-of select="substring(
                CourseDescription_Name,1,7)"/><xsl:apply-templates/>
            </xsl:attribute>
            <xsl:apply-templates/>
        </div>
</xsl:template>

Generating an id Attribute for a div

In the next template, the value of the <CourseDescription_Major> element is being used to generate the div’s id value, such as <div id="Accounting">. The dot in the xls:value-of select="." will be replaced with the word Accounting (the dot notation means “self,” or the current element’s content). See Figure 10-17.

Figure 10-17. An XSL template to generate a div id from element text

<xsl:attribute name="href">file://path/filename.ext
</xsl:attribute>

<xsl:attribute name="href">file:///C:/test/images/filename.ext
</xsl:attribute>

<xsl:attribute name="href">file://images/filename.ext
</xsl:attribute>.

You can use Edit→Find/Change as a means of locating specific types of styling in your document that you would like to mark up as XML elements. The process is described in the Adobe InDesign Technical Reference documentation, available on the Adobe website. The Find/Change dialog has an expression language that lets you write a pattern to search for and a pattern to replace the found text. Using the Find/Change dialog, you can select an XML element to apply from the Tags list (the tags must already be available in your InDesign document, either from using Load Tags or Load DTD).

This method can be very helpful for applying or fixing up XML markup, such as when you decide to change the name of an XML element after it has been applied. A common example is to search for a bold override or a character style that applies bold to the underlying text and tag it as the element <b>. (I would not recommend using Find/Change if you are working with a linked XML file that you have imported into InDesign.)