

<!--#include virtual="/doctype.html" -->
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    
    <link href="/css/ooo.css" rel="stylesheet" type="text/css">
    
	<META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=windows-1252">
	<TITLE>The StarOffice XML based file format</TITLE>
	<META NAME="GENERATOR" CONTENT="StarOffice 6.0  (Win32)">
	<META NAME="AUTHOR" CONTENT="Daniel Vogelheim">
	<META NAME="CREATED" CONTENT="20010803;16470900">
	<META NAME="CHANGEDBY" CONTENT="Daniel Vogelheim">
	<META NAME="CHANGED" CONTENT="20010821;15101200">
	<STYLE>
	<!--
		@page { margin: 2cm }
		P { margin-bottom: 0.21cm; text-align: justify }
		H1 { margin-bottom: 0.21cm; font-family: "Arial", sans-serif; font-size: 16pt }
		H2 { margin-bottom: 0.21cm; font-family: "Arial", sans-serif; font-size: 14pt; font-style: normal }
		H3 { margin-bottom: 0.21cm; font-family: "Arial", sans-serif; font-size: 12pt }
	-->
	</STYLE>

    
    <script src="https://www.apachecon.com/event-images/snippet.js"></script>
  </head>
  <body>
    <!--#include virtual="/brand.html" -->
    <div id="topbara">
      <!--#include virtual="/topnav.html" -->
      <div id="breadcrumbsa"><a href="/">home</a>&nbsp;&raquo;&nbsp;<a href="/xml/">xml</a></div>
    </div>
    <div id="clear"></div>
      
      
    <div id="content">
      
      
<P ALIGN=JUSTIFY STYLE="margin-top: 0.42cm; page-break-after: avoid"><FONT FACE="Arial, sans-serif"><FONT SIZE=5>The
StarOffice XML based file format</FONT></FONT></P>
<P ALIGN=JUSTIFY STYLE="margin-top: 0.2cm; margin-bottom: 2cm; page-break-after: avoid">
<FONT FACE="Arial, sans-serif"><FONT SIZE=3>To boldly go where no
office suite has gone before</FONT></FONT></P>
<H1>1Introduction</H1>
<P>StarOffice 6.0 and OpenOffice.org use a new, XML based file format
for all its documents. The constituent parts of an office document,
content, layout and meta information, are stored as XML streams
inside a ZIP file, along with embedded graphics and objects contained
in the document.</P>
<P>Before musing on the technical virtues and uses of the XML based
file format, it should be noted that the format as well as the
OpenOffice.org application, which serves as a reference
implementation for the format, are available under a GNU license.
This open and free licensing guarantees that you are not at the mercy
of a single company for improvements and fixes of the format or its
supporting software, thus providing very strong protection for all
investments and efforts you put into this format. Additionally, Sun
aims at standardizing the format, thus providing any interested
parties with a way to participate in the evolution of the format.</P>
<P>The next chapter will introduce several features of the XML
format, followed by a chapter in which benefits can be derived from
these features for various types of users. Finally, a conclusion will
be presented.</P>
<H1>2How It Works &#150; The Means</H1>
<P>This chapter will highlight several technicalities of the XML
based file format. The following chapter will then show how to put
these into use.</P>
<H2>2.1Separation of Content, Layout, and Meta Information</H2>
<P STYLE="font-style: normal">An office document contains content,
for example the text of a letter, or the data in a spreadsheet, along
with layout information, which describes how the content should look
like. Also part of document is meta information like who edited a
document and how it is called, or additional information such as
images or embedded objects. To a user, these are inseparable parts of
a single document. But for processing the document, it makes sense to
separate them such that they can be read, interpreted and modified
independently of each other. To facilitate this, the StarOffice XML
file format stores content, layout, meta information, images and
embedded objects in separate streams of a ZIP based package file. The
whole file contains the whole document, the individual streams
contain the constituent parts of the document.</P>
<H2>2.2Standards Based</H2>
<P>When creating the XML based file format, we tried to gain as much
as was possible from related standards. The very use of XML is one
example. The ZIP format we use for packages are in widespread use.
Many elements and attributes are borrowed from HTML, XSL-FO, XLink,
Dublin Core, or SVG. For Math, we use MathML. This allows easy
transformation from and into those formats, and also it allows people
to quickly understand our format, if they are already familiar with
those formats we make use of.</P>
<H2>2.3Uniform Representation of Formatting and Layout Information</H2>
<P>The StarOffice and OpenOffice.org applications distinguish between
formatting through styles and <I>direct</I> formatting, which means
applying formatting directly to text or cell ranges. In the XML
format, these different ways to format a document use the same
style-based representation. The <I>direct</I> formatting is
automatically converted into <I>automatic styles</I>,  which is a
style-based formatting equivalent of the <I>direct</I> formatting the
user applied to the document.</P>
<H2>2.4Structured Format</H2>
<P STYLE="font-style: normal">A primary design goal of the XML format
was to represent all structured information contained in an document
as XML structures, thus making the document fully accessible to
standard XML tools.  This is a quite different solution to, for
example, an XHTML/CSS solution, where all CSS formatting information
is encoded in a text-only format. This way, all layout information
appears as a single string to an XSLT processor, making it very hard
to process the layout information in any way.</P>
<H2>2.5Idealized Format</H2>
<P><SPAN STYLE="font-style: normal">Our XML file format is a properly
designed file format, as opposed </SPAN>to a mere XML dump o<SPAN STYLE="font-style: normal">f
core structures with all their implementation details and
limitations. The documents are represented in a way which is easy to
understand and use, and not in a way which is easy to implement. This
allows the format to abstract application peculiarities and therefore
the format may also be used by applications other than StarOffice and
OpenOffice.org. Throughout the development of the format, great care
was taken to make sure the file format is easy to process. Also, the
idealized representation makes it easier to improve the StarOffice
and OpenOffice.org applications without having to make major changes
to the format itself.</SPAN></P>
<H2>2.6Common Format Across All Office Applications</H2>
<P STYLE="font-style: normal">The same format is used across all
office applications. Similar concepts in the different applications
always use the same XML representation. For example, spreadsheet
tables and word processor tables share a common XML representation,
even though their implementations and limitations are quite
different. This has great advantages when processing or generating
StarOffice files: The same code works for all applications. For
example, a single XSLT style sheet can process both spreadsheets and
text documents.</P>
<H2>2.7Open For Extensions and Supplemental Information</H2>
<P STYLE="font-style: normal">Arbitrary XML attributes may be
attached to style information and will be preserved when editing such
a modified file with StarOffice. Because all formatting information
is uniformly represented as styles, and because any document content
can be formatted using styles, this allows arbitrary information to
be attached to any part of the document content. Further means to add
supplemental information, such as allowing complete streams to be
part of the packages, may be added.</P>
<H1>3What You Gain &#150; The Ends</H1>
<P>The previous chapter has highlighted several features and
mechanisms of our new file format. This chapter will look at how this
helps different groups of users.</P>
<H2>3.1Office Users</H2>
<P>To the user of StarOffice and OpenOffice.org, the main benefits
may be summarized as increased robustness, openness, document
longevity, and version interoperability. In additional, the user will
gain additional benefits as the document processing and additional
solutions described in the following chapters become reality.</P>
<H3>Increased Robustness</H3>
<P>To a user, their own documents are usually valuable resources,
into which lots of time and effort has been invested. What happens,
if through an error in the used hardware or software used, the
documents become corrupted? With a binary format, the user is at the
mercy of the original application: If it can still read or recover
the document, all is well. If not, the document is lost. 
</P>
<P STYLE="font-style: normal">XML makes it easy to ignore and
tolerate problems in the documents, so the likelihood of lost
documents is reduced. Additionally, the human readable/editable
nature of XML allows advanced users or service personnel to inspect
corrupt files and restore the documents, even without specialized
tools or very much in-depth knowledge.</P>
<H3>Document Archiving</H3>
<P>For some users, long-term storage of documents is important. With
binary file formats, documents can be read only as long as the
supporting application as well as the system it runs on exists. XML,
being a text based and human readable format, allows files to be read
even if the original application (or the OS, or the hardware it ran
on) are not available anymore. Additionally, the thorough
documentation of the format allows the files to be fully interpreted.</P>
<H3>Version Interoperability</H3>
<P>A well-known problem with office documents is a file format
versioning problem: New versions of the office suite usually come
with a new version of a file format, which the older version don't
know about. To be able read the newer documents, users find
themselves forced to upgrade their application.</P>
<P>Contrast this with an XML based format: XML is extensible, making
it easy to to add new features to the format without loosing the
ability to read older files. Older applications will simply ignore
the new (and, to them, unknown) content, thus reading the newer files
as well as they can. The result is a high degree of forwards and
backwards compatibility. 
</P>
<H3>Documented and Transparent File Content</H3>
<P>With the XML file format, the user can finally inspect the content
of files that are being sent or received. If yet another macro virus
threatens your organization, a simple combination of unzip and grep
allows you to check for suspicious content. If you want to make sure
that files you send to other people don't contain sensitive
information, then now you can simply look at them. Or if you need to
quickly find a certain document, just use Unix grep or the Windows
Explorer context menu  to search through the meta information, which
are stored as plain text.</P>
<H2>3.2Document Processing and Developers</H2>
<P>Advanced users and developers may want to make use of the new
freedom the StarOffice XML file brings them, and use and process
StarOffice files with other tools and applications. There are several
advantages for them:</P>
<H3>Standards Based and Openness</H3>
<P>The StarOffice XML file format relies on many standards in
addition to the actual XML standard itself: It makes use of elements
and attributes from HTML, XLink, XSL-FO, Dublin Core, and SVG.
Developers familiar with these can easily pick up on the StarOffice
format. Also, a developer has a wide choice of tools and code
libraries for many programming languages that allow processing and
manipulation of XML or ZIP files.</P>
<P>This use of established standards is particularly useful for
making office documents available outside of traditional PC
applications. For example, by transforming our office documents into
HTML, you can make them available through the World Wide Web. Similar
transformations are  into WAP or XSL-FO are possible. 
</P>
<P>An example of transforming our documents into HTML is available on
the OpenOffice.org website, and another one is available through the
xml.com website (see reference at the end of this paper). 
</P>
<H3>Easy Import and Export of Other File Formats</H3>
<P>Import and export of other '<I>foreign</I>' file formats can be
accomplished by converting the document into the XML file format.
This approach has several advantages:</P>
<OL>
	<LI><P>The XML file format provides the developer with a clean,
	documented target.</P>
	<LI><P>Due to XML's human readability, debugging becomes much
	easier.</P>
	<LI><P>The file format and the StarOffice API hide the details of a
	particular office version, so the developer doesn't have to
	recompile and update the import/export component for every new
	version of StarOffice.</P>
	<LI><P>Several XML based import or export components may be chained
	to each other. This can be used to convert between two
	non-StarOffice formats.</P>
	<LI><P>Import and Export components can be integrated into
	StarOffice and OpenOffice.org, or they can be used stand-alone. In
	the latter mode, they could be used e.g. for batch conversion of
	many files. Also, they can be used to view StarOffice XML documents
	without having to start the full StarOffice application.</P>
</OL>
<H3>Leverage Available Infrastructures</H3>
<P>Being based on XML and ZIP, the StarOffice file format can be used
with the growing number of widely available tools that can process
these formats. Examples are:</P>
<OL>
	<LI><P>XML viewers and editors</P>
	<P>Any of the available XML viewers can be used to examine the
	document content. XML Editors can be used to manually make changes
	to the document content or its layout.</P>
	<LI><P>XML transformations</P>
	<P>XML transformation tools and libraries, such as XSLT engines or
	XPathScript (Perl), can be used to automatically edit, modify or
	generate StarOffice documents.</P>
	<LI><P>XML Databases</P>
	<P>There is a growing number of XML aware database and storage
	products. These may be used to store, index, query and manipulate
	StarOffice documents.</P>
	<LI><P>ZIP tools</P>
	<P>With the package mechanism using the well-known ZIP format,
	standard ZIP tools may be used to change the package content. For
	example, using any ZIP tool, embedded graphics can be changed from
	low resolution to high resolution ones before giving a document to a
	print shop.</P>
</OL>
<H2>3.3Solution Providers</H2>
<P>A generic office suite may not be the right solution for everyone.
Often, significant improvements to productivity can be achieved by
using custom software solutions tailored exactly to the requirements
of a particular organization. StarOffice and OpenOffice.org can
become part of such a solution, supplying office functionality as
part of an larger, fully integrated package. Solution providers who
want to integrate StarOffice or OpenOffice.org into their software
will find the XML file format along with the open StarOffice API to
be the enabling features for this.</P>
<H3>StarOffice as Editor Component</H3>
<P>The StarOffice API enables the use of StarOffice as an editor
component. In this mode of operation, StarOffice may appear as an
edit area within the custom application, controlled through the API.
The custom application only needs to represent its own data in the
StarOffice XML file format and hand it to the StarOffice component.
When the editing is done, the custom application can then convert the
XML data stream back into its own, native format for storage or
further processing.</P>
<H3>Search Engines / Knowledge Management Systems</H3>
<P STYLE="font-style: normal">The use of XML makes office documents
accessible to search engines and more advanced knowledge management
systems. Since the full document structure is available as XML,
knowledge management system could easily extract or value document
content based on how or where it is contained in the document.</P>
<P STYLE="font-style: normal">Search engines can usually been
configured for different file types. To index and search StarOffice
XML files, all that is necessary is to teach the search engine to run
the venerable 'unzip' command on each file before processing it.</P>
<H3>Document Management</H3>
<P STYLE="font-style: normal">StarOffice and OpenOffice.org are
ideally suited for integration into document management systems.
Here, a key feature is the ability to attach additional data to
documents or parts of documents. A document management system can use
this to include additional information into the documents while still
keeping the documents fully editable by the user. As detailed above,
StarOffice and OpenOffice.org may additionally be used as editing
components inside the document management system.</P>
<H3>Partial Editing and Two-way Conversion</H3>
<P>Custom applications may want to modify or update office documents
based on specific data or computations. XML makes it easy to identify
specific parts of a document and to replace them. The separation of
content and layout further helps this because it allows changing one
without having to change the other.</P>
<P>A similar approach is to extract data from a StarOffice document
and process it in some way. Then, merge the new data into the
document again, or just recreate the document based on the new data.
Such back-and-forth conversions are simplified by XML's nature, and
the content/layout separation.</P>
<P>This technique could be used to support StarOffice documents (or
parts of documents) on resource constrained devices, such as PDAs. 
</P>
<H3>StarOffice as Layout Engine</H3>
<P><SPAN STYLE="font-style: normal">At the end of the data processing
chain, a </SPAN>custom application may need to present data to users
or generate printable documents, summaries and reports. When using
StarOffice, this can be achieved by converting the presentation data
into the StarOffice XML file format, and loading it into StarOffice
for layout and printing. This way, the full power of StarOffice can
be leveraged for professionally looking documents without having to
recreate the entire formatting and layout logic. Once again, the
separation of content and layout helps, as it allows painless
generation of the plain content data, which can then be combined with
professional, artistic layout information.</P>
<H1>4Conclusion</H1>
<P>The upcoming StarOffice 6.0 and OpenOffice.org both feature a new
XML based file format, which stores document content, layout, and
meta information as XML inside of a ZIP package, along with embedded
graphics and objects. This organization as well as many details in
the XML format itself provide many advantages to various groups of
users, creating a win-win situation for all end users, developers and
solution providers that make use of it.</P>
<H1>5Online Resources and Further information</H1>
<P ALIGN=LEFT>OpenOffice.org XML Homepage: <A HREF="http://xml.openoffice.org/">http://xml.openoffice.org/</A></P>
<P ALIGN=LEFT>StarOffice/OpenOffice.org XML based file format
definition: <A HREF="http://xml.openoffice.org/xml_specification.pdf">http://xml.openoffice.org/xml_specification.pdf</A></P>
<P ALIGN=LEFT>The StarOffice/OpenOffice.org API:
<A HREF="http://api.openoffice.org/">http://api.openoffice.org/</A></P>
<P ALIGN=LEFT>&#147;Adventures with OpenOffice and XML&#148; by Matt
Sergeant: <A HREF="http://www.xml.com/pub/a/2001/02/07/openoffice.html">http://www.xml.com/pub/a/2001/02/07/openoffice.html</A></P>
<P ALIGN=LEFT>OpenOffice.org Filter-Development Using XML:
<A HREF="http://xml.openoffice.org/filter/">http://xml.openoffice.org/filter/</A></P>

      
    </div>
    <!--#include virtual="/footer.html" -->
  </body>
</html>