Home > Articles > Web Services > XML

  • Print
  • + Share This
This chapter is from the book

This chapter is from the book

Generating XML Documents

Where do XML documents come from? It's kind of like the famous question: Which came first, the chicken or the egg? You can't parse an XML document until you build one. The source data for an XML document can come from just about any imaginable source. For example, an XML document can be generated from a CSV file, a tab-delimited text file, the results of a database query, a Common Gateway Interface (CGI) web-based user input form that collects data from a user, Web services, and many, many other sources. You can see that there is an almost infinite number of data sources for XML documents.

Let's take a look at two methods of generating XML documents. First, an XML document can be created in a standard text editor or an XML-specific What You See Is What You Get (WYSIWYG) editor. This is called static generation because the XML document is created by typing the document into a text editor. The data in the file remains the same unless someone or something (that is, an application) modifies it. There isn't too much to it—you basically just type the contents of the XML file as you would type any other document. This is an option for very small XML files (for example, configuration files); however, it isn't practical for larger files. The larger and more complicated an XML document is, the greater the chance of error if the file is edited by hand.

XML documents can also be generated dynamically by an application. Dynamically generating XML is more interesting and applicable than statically generated documents, so let's take a more detailed look at this topic in the following section.

Dynamically Generating XML Documents

Another method of generating an XML document is to dynamically generate the contents using an application (preferrably Perl based). Because XML is just plain text, an entire XML document can be easily contained within a Perl scalar. It also can be printed to any filehandle with a simple print command. Of course, plenty of modules are available that generate XML, which takes away some of complexities of doing everything yourself. We'll discuss these modules in Part III of this book, "Generating XML Documents Using Perl Modules." Some of the topics discussed include generating XML documents from text files, databases, and even other XML documents.

A good example to demonstrate dynamic XML file generation is a web form that is filled out by a user and then submitted to a Perl application running on the web server. This is certainly dynamic because we don't know what the user will enter as data. Assume that the web form shown in Figure 2.3 allows the user to fill out certain information and then submit the collected information to the server. The information provided by the user will be processed by a Perl script and used as input or source information for an XML document. An XML document will be generated containing the information provided by the user.

Figure 2.3 Web-based HTML submission form used to collect data for our XML document.

We won't get into too much detail here, but we will revisit this example in Chapter 5, "Generating XML Documents from Text Files." The purpose here is to provide a few high-level examples to illustrate the concepts instead of diving right into source code.

When the Perl application receives the information from the form, it comes in a certain format. The Perl application can then parse this format to separate each field individually. Let's say the user fills in the required information and then submits the form. Now, inside our Perl application, we have the following data:

First Name: John
Last Name: Smith
Address: 1155 Perl Drive
City: Los Angeles
State: California
Zip: 90102
Phone Number: 818-555-1212 

The Perl script can now process and modify the data and then generate an XML document containing this information. Listing 2.2 shows the submitted data in an XML document. This file now can be processed as an XML document. For example, now that the information submitted by the user is in XML, you have a variety of options. The XML document can be transformed to another format (using XSLT), searched (using Xpath), or sent to another application as a document that is based on an agreed-to format.

Listing 2.2 Sample XML file generated from the web-based form input. (Filename: ch2_webform_input.xml)

<?xml version="1.0"?>
 <address>1155 Perl Drive.</address>
 <city>Los Angeles</city>

This wasn't a very complicated example. As you can see, we've mapped the web form names (for example, first name, last name, and so forth) to element names inside the XML document for consistency. This is a good example of when you would dynamically generate XML.

Now that we have discussed XML file generation, we can proceed to more complex issues, such as searching XML data and transforming XML into other data formats.

  • + Share This
  • 🔖 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.


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.


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.


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.


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


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


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.


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.


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