Home > Articles > Web Services > XML

Sams Teach Yourself XML in 21 Days

Sep 16, 2005

📄 Contents

␡

⎙ Print

< Back Page 121 of 288 Next >

Recommended Book 

Sams Teach Yourself XML in 21 Days, 3rd Edition

Learn More Buy

Using XSL-FO

You've already seen a short XSL-FO example, but in fact, XML documents are only rarely formatted by directly using formatting objects as in the example you've seen because the process becomes too complex. What usually happens is that you take an XML document (with the extension .xml), run it through an XSLT processor to create a new XML document that uses XSL-FO (with the extension .fo), and then use an XSL-FO processor to create the formatted display document (with the extension .pdf in today's discussion). You do things this way because any document except a nontrivial one has many paragraphs of text or data, and to format each one by hand would be a time-consuming process.

In fact, XSLT was originally developed for formatting XML documents by using XSL-FO objects. Since then, being able to access XML data without writing software using XSLT in itself has become so powerful that XSLT has outstripped XSL-FO in popularity.

For example, say that you want to use XSL-FO to format the XML document with state data that you worked with yesterday. Let's use that document today, renaming it ch10_01.xml, as shown in Listing 10.1.

Example 10.1. An Example of an XML Document (`ch10_01.xml`)

<?xml version="1.0" encoding ="UTF-8"?>
<states>

    <state>
        <name>California</name>
        <population units="people">33871648</population><!--2000 census-->
        <capital>Sacramento</capital>
        <bird>Quail</bird>
        <flower>Golden Poppy</flower>
        <area units="square miles">155959</area>
    </state>

    <state>
        <name>Massachusetts</name>
        <population units="people">6349097</population><!--2000 census-->
        <capital>Boston</capital>
        <bird>Chickadee</bird>
        <flower>Mayflower</flower>
        <area units="square miles">7840</area>
    </state>

    <state>
        <name>New York</name>
        <population units="people">18976457</population><!--2000 census-->
        <capital>Albany</capital>
        <bird>Bluebird</bird>
        <flower>Rose</flower>
        <area units="square miles">47214</area>
    </state>

</states>

As you'll see later today, the XSL-FO document holding this data that you're going to feed into an XSL-FO processor is about three times the length of ch10_01.xml, which is why it makes sense to use XSLT to convert ch10_01.xml into a document that uses XSL-FO. Let's take a look at the XSLT style sheet that will do that.

Using XSLT to Create an XSL-FO Document

Although you could format ch10_01.xml by hand, it's easier to use an XSLT style sheet to do so. Listing 10.2 contains the style sheet (ch10_02.xml) that you're going to use in this example. In this case, you're just going to extract the state data from ch10_01.xml and present that data in a list form, using 18-point font.

Example 10.2. An XSL Document That Adds XSL-FO Formatting (`ch10_02.xsl`)

<?xml version='1.0'?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:fo="http://www.w3.org/1999/XSL/Format"
    version='1.0'>

    <xsl:template match="states">
        <fo:root>

            <fo:layout-master-set>
                 <fo:simple-page-master master-name="mainPage"
                     page-height="300mm" page-width="200mm"
                     margin-top="20mm" margin-bottom="20mm"
                     margin-left="20mm" margin-right="20mm">

                     <fo:region-body
                       margin-top="0mm" margin-bottom="10mm"
                       margin-left="0mm" margin-right="0mm"/>

                     <fo:region-after extent="20mm"/>
                 </fo:simple-page-master>
             </fo:layout-master-set>

             <fo:page-sequence master-reference="mainPage">
                 <fo:flow  flow-name="xsl-region-body">
                     <xsl:apply-templates/>
                 </fo:flow>
             </fo:page-sequence>

        </fo:root>
    </xsl:template>

    <xsl:template match="state/name">
        <fo:block font-weight="bold" font-size="18pt"
            line-height="24pt" font-family="sans-serif"
            text-decoration="underline">
            Name:
            <xsl:value-of select="."/>
        </fo:block>
    </xsl:template>

    <xsl:template match="state/population">
        <fo:block font-size="18pt" line-height="24pt"
            font-family="sans-serif">
            Population (people):
            <xsl:value-of select="."/>
        </fo:block>
    </xsl:template>

    <xsl:template match="state/capital">
        <fo:block font-size="18pt" line-height="24pt" font-family="sans-serif">
            Capital:
            <xsl:value-of select="."/>
        </fo:block>
    </xsl:template>

    <xsl:template match="state/bird">
        <fo:block font-size="18pt" line-height="24pt" font-family="sans-serif">
            Bird:
            <xsl:value-of select="."/>
        </fo:block>
    </xsl:template>

    <xsl:template match="state/flower">
        <fo:block font-size="18pt" line-height="24pt" font-family="sans-serif">
            Flower:
            <xsl:value-of select="."/>
        </fo:block>
    </xsl:template>

    <xsl:template match="state/area">
        <fo:block font-size="18pt" line-height="24pt" font-family="sans-serif">
            Area (square miles):
            <xsl:value-of select="."/>
        </fo:block>
    </xsl:template>

</xsl:stylesheet>

Today you'll see how ch10_02.xsl works and what it does. The first step, as described in the following section, is to put this style sheet to work and create the XSL-FO document.

Creating an XSL-FO Document by Using an XSLT Style Sheet

You're ready to create an XSL-FO document, which you can call ch10_03.fo. This document is the one you'll feed into an XSL-FO processor to create a formatted PDF document that will display the data from the XML document ch10_01.xml. To create ch10_03.fo, you only need to apply the XSLT style sheet ch10_02.xsl to the XML document ch10_01.xml. For example, if you have Java 1.4 or later installed, you can use the Java file ch09_05.class that is in the code download area for this book that you used yesterday, like this:

%java ch09_05 ch10_01.xml ch10_02.xsl ch10_03.fo

This creates ch10_03.fo, which is ch10_01.xml formatted with XSL-FO. Listing 10.3 presents ch10_03.fo; note the length of it compared to the original XML document, ch10_01.xml, and you can see why it's a good idea to use XSLT to create XSL-FO documents if you're working with data of any significant length.

Example 10.3. An XSL-FO Document (`ch10_03.fo`)

<?xml version="1.0" encoding="UTF-8"?>
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
    <fo:layout-master-set>
        <fo:simple-page-master margin-right="20mm"
            margin-left="20mm" margin-bottom="20mm" margin-top="20mm"
            page-width="200mm" page-height="300mm" master-name="mainPage">
            <fo:region-body margin-right="0mm" margin-left="0mm"
                margin-bottom="10mm" margin-top="0mm"/>
            <fo:region-after extent="20mm"/>
        </fo:simple-page-master>
    </fo:layout-master-set>

    <fo:page-sequence master-reference="mainPage">
        <fo:flow flow-name="xsl-region-body">

            <fo:block text-decoration="underline" font-family="sans-serif"
                line-height="24pt" font-size="18pt" font-weight="bold">
                Name:
                California
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Population (people):
                33871648
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Capital:
                Sacramento
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Bird:
                Quail
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Flower:
                Golden Poppy
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Area (square miles) :
                155959
            </fo:block>

            <fo:block text-decoration="underline" font-family="sans-serif"
                line-height="24pt" font-size="18pt" font-weight="bold">
                Name:
                Massachusetts
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Population (people):
                6349097
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Capital:
                Boston
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Bird:
                Chickadee
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Flower:
                Mayflower
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Area (square miles):
                7840
            </fo:block>

            <fo:block text-decoration="underline" font-family="sans-serif"
                line-height="24pt" font-size="18pt" font-weight="bold">
                Name:
                New York
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Population (people):
                18976457
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Capital:
                Albany
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Bird:
                Bluebird
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Flower:
                Rose
            </fo:block>
            <fo:block font-family="sans-serif" line-height="24pt"
                font-size="18pt">
                Area (square miles):
                47214
            </fo:block>

        </fo:flow>
    </fo:page-sequence>
</fo:root>

You now have ch10_03.fo, which is ready to feed into an XSL-FO processor.

Creating a PDF Document

To use ch10_03.fo and convert it into a PDF file, ch10_04.pdf, you can use what is probably the most popular XSL-FO processor, the Apache XML Project's FOP. You can get FOP for free at http://xml.apache.org/fop; just click the Download button. The current version as of this writing is 0.20.4 (0.20.5 is available in a release candidate version, but it's not yet official), and it's written in Java, which means you have to have Java installed in order to use it. The compressed file you download is fop-0.20.4-bin.tar.gz. (.tar.gz files are targeted to Unix, but Windows unzip utilities, such as WinZip, from http://www.winzip.com, can unzip them as well.)

Here's how to use FOP to convert ch10_03.fo into ch10_04.pdf, assuming that ch10_03.fo is in the same directory where you unzipped FOP (the -cp switch here sets the Java classpath variable, which you'll discuss further on Day 16, "Using Java and .NET: DOM"):

%java -cp build\fop.jar;lib\batik.jar;lib\xalan-2.3.1.jar;
lib\xercesImpl-2.0.1.jar;lib\xml-apis.jar;
lib\avalon-framework-cvs-20020315.jar;lib\logkit-1.0.jar;
lib\jimi-1.0.jar org.apache.fop.apps.Fop ch10_03.fo ch10_04.pdf

This is not very easy to type, so FOP also supplies shell scripts for most shells, including a .bat file for Windows, which means that the following is usually all you have to type:

%fop ch10_03.fo ch10_04.pdf

This creates ch10_04.pdf, which is the goal you've been working toward. To view this PDF document, you can use the Adobe Acrobat PDF viewer, which you can download for free from Adobe at http://www.adobe.com (currently, Adobe Acrobat reader is available at http://www.adobe.com/products/acrobat/readermain.html). Figure 10.1 shows ch10_04.pdf in Adobe Acrobat. As you can see in the figure, the data from the XML document has indeed been formatted into a PDF document.

Figure 10.1 Formatting XML data in PDF format.

Now take a look at how to create your own XSL-FO formatting.

< Back Page 121 of 288 Next >

🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Privacy Notice

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
Such marketing is consistent with applicable law and Pearson's legal obligations.
Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

As required by law.
With the consent of the individual (or their parent, if the individual is a minor)
In response to a subpoena, court order or legal process, to the extent permitted or required by law
To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
To investigate or address actual or suspected fraud or other illegal activities
To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020

Email Address