zengine/tinyxml.txt

/** @mainpage

<h1> TinyXml </h1>

TinyXml is a simple, small, C++ XML parser that can be easily 
integrating into other programs.


<h2> What it does. </h2>
	
In brief, TinyXml parses an XML document, and builds from that a 
Document Object Model (DOM) that can be read, modified, and saved.

XML stands for "eXtensible Markup Language." It allows you to create 
your own document markups. Where HTML does a very good job of marking 
documents for browsers, XML allows you to define any kind of document 
markup, for example a document that describes a "to do" list for an 
organizer application. XML is a very structured and convenient format.
All those random file formats created to store application data can 
all be replaced with XML. One parser for everything.

There are different ways to access and interact with XML data.
TinyXml uses a Document Object Model (DOM), meaning the XML data is parsed
into a tree objects that can be browsed and manipulated, and then 
written back to disk. You can also construct an XML document from
scratch with C++ objects and write this to disk (or another output
stream.)

TinyXml is designed to be easy and fast. It is two headers and four cpp 
files. Simply add these to your project and off you go. There is an 
example to get you started. It is released under the ZLib license, 
so you can use it in open source or commercial code.

It attempts to be a flexible parser, but with truly correct and
compliant XML output (with the exception of the character set,
below.) TinyXml should compile on any reasonably C++
system. It does not rely on exceptions or RTTI. It can be 
compiled with or without STL support.


<h2> What it doesn't do. </h2>

It doesnt parse or use DTDs (Document Type Definitions) or XSLs
(eXtensible Stylesheet Language.) It is only tested on Latin-1 
characters (which is the Western European character set). 
Although people have reported success in passing through Latin-1 
and UTF-8 data. There are other parsers out there (check out
www.sourceforge.org, search for XML) that are much more fully
featured. But they are also much bigger, take longer to set up in
your project, have a higher learning curve, and often have a more
restrictive license. If you are working with browsers or have more
complete XML needs, TinyXml is not the parser for you.


<h2> Code Status.  </h2>

TinyXml is mature, tested code. It is very stable. If you find
bugs, send them in and we'll get them straightened out as soon as possible.

There are some areas of improvement; please check sourceforge if you are
interested in working on TinyXml.


<h2> Features </h2>

<h3> Using STL </h3>

TinyXml can be compiled to use or not use STL. When using STL, TinyXml
uses the std::string class, and fully supports std::istream, std::ostream,
operator<<, and operator>>. Many API methods have both 'const char*' and
'const std::string&' forms.

When STL support is compiled out, no STL files are included whatsover. All
the string classes are implemented by TinyXml itself. API methods
all use the 'const char*' form for input.

Use the compile time #define:

	TIXML_USE_STL

to compile one version or the other. This can be passed by the compiler,
or set as the first line of "tinyxml.h".

Note: If compiling the test code in Linux, setting the environment
variable TINYXML_USE_STL=YES/NO will control STL compilation. In the
Windows project file, STL and non STL targets are provided. In your project,
its probably easiest to add the line "#define TIXML_USE_STL" as the first
line of tinyxml.h.


<h3> Entities </h3>
TinyXml recognizes the pre-defined "entity references", meaning special
characters. Namely:

@verbatim
	&amp;	&
	&lt;	<
	&gt;	>
	&quot;	"
	&apos;
@endverbatim

These are recognized when the XML document is read, and translated to there
ASCII equivalents. For instance, text with the XML of:

@verbatim
	Far &amp; Away
@endverbatim

will have the Value() of "Far & Away" when queried from the TiXmlText object,
but will be written back to the XML stream/file as an entitity.


<h3> Streams </h3>
With TIXML_USE_STL on,
TiXml has been modified to support both C (FILE) and C++ (operator <<,>>) 
streams. There are some differences that you may need to be aware of.

C style output:
	- based on FILE*
	- the Print() and SaveFile() methods

	Generates formatted output, with plenty of white space, intended to be as 
	human-readable as possible. They are very fast, and tolerant of ill formed 
	XML documents. For example, an XML document that contains 2 root elements 
	and 2 declarations, will print.

C style input:
	- based on FILE*
	- the Parse() and LoadFile() methods

	A fast, tolerant read. Use whenever you don't need the C++ streams.

C++ style ouput:
	- based on std::ostream
	- operator<<

	Generates condensed output, intended for network transmission rather than
	readability. Depending on your system's implementation of the ostream class,
	these may be somewhat slower. (Or may not.) Not tolerant of ill formed XML:
	a document should contain the correct one root element. Additional root level
	elements will not be streamed out.

C++ style input:
	- based on std::istream
	- operator>>

	Reads XML from a stream, making it useful for network transmission. The tricky
	part is knowing when the XML document is complete, since there will almost
	certainly be other data in the stream. TinyXml will assume the XML data is
	complete after it reads the root element. Put another way, documents that
	are ill-constructed with more than one root element will not read correctly.
	Also note that operator>> is somewhat slower than Parse, due to both 
	implementation of the STL and limitations of TinyXml.

<h3> White space </h3>
The world simply does not agree on whether white space should be kept, or condensed.
For example, pretend the '_' is a space, and look at "Hello____world". HTML, and 
at least some XML parsers, will interpret this as "Hello_world". They condense white
space. Some XML parsers do not, and will leave it as "Hello____world". (Remember
to keep pretending the _ is a space.) Others suggest that __Hello___world__ should become
Hello___world.

It's an issue that hasn't been resolved to my satisfaction. TinyXml supports the
first 2 approaches. Call TiXmlBase::SetCondenseWhiteSpace( bool ) to set the desired behavior.
The default is to condense white space.

If you change the default, you should call TiXmlBase::SetCondenseWhiteSpace( bool )
before making any calls to Parse XML data, and I don't recommend changing it after
it has been set.


<h3> Handles </h3>

Where browsing an XML document in a robust way, it is important to check
for null returns from method calls. An error safe implementation can
generate a lot of code like:

@verbatim
TiXmlElement* root = document.FirstChildElement( "Document" );
if ( root )
{
	TiXmlElement* element = root->FirstChildElement( "Element" );
	if ( element )
	{
		TiXmlElement* child = element->FirstChildElement( "Child" );
		if ( child )
		{
			TiXmlElement* child2 = child->NextSiblingElement( "Child" );
			if ( child2 )
			{
				// Finally do something useful.
@endverbatim

Handles have been introduced to clean this up. Using the TiXmlHandle class,
the previous code reduces to:

@verbatim
TiXmlHandle docHandle( &document );
TiXmlElement* child2 = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).Child( "Child", 1 ).Element();
if ( child2 )
{
	// do something useful
@endverbatim

Which is much easier to deal with. See TiXmlHandle for more information.


<h3> Row and Column tracking </h3>
Being able to track nodes and attributes back to their origin location
in source files can be very important for some applications. Additionally,
knowing where parsing errors occured in the original source can be very
time saving.

TinyXml can tracks the row and column origin of all nodes and attributes
in a text file. The TiXmlBase::Row() and TiXmlBase::Column() methods return
the origin of the node in the source text. The correct tabs can be 
configured in TiXmlDocument::SetTabSize().


<h2> Using and Installing </h2>

To Compile and Run xmltest:

A Linux Makefile and a Windows Visual C++ .dsw file is provided. 
Simply compile and run. It will write the file demotest.xml to your 
disk and generate output on the screen. It also tests walking the
DOM by printing out the number of nodes found using different 
techniques.

The Linux makefile is very generic and will
probably run on other systems, but is only tested on Linux. You no
longer need to run 'make depend'. The dependecies have been
hard coded.

<h3>Windows project file for VC6</h3>
<ul>
<li>tinyxml:		tinyxml library, non-STL </li>
<li>tinyxmlSTL:		tinyxml library, STL </li>
<li>tinyXmlTest:	test app, non-STL </li>
<li>tinyXmlTestSTL: test app, STL </li>
</ul>

<h3>Linux Make file</h3>
At the top of the makefile you can set:

PROFILE, DEBUG, and TINYXML_USE_STL. Details (such that they are) are in
the makefile.

In the tinyxml directory, type "make clean" then "make". The executable
file 'xmltest' will be created.



<h3>To Use in an Application:</h3>

Add tinyxml.cpp, tinyxml.h, tinyxmlerror.cpp, tinyxmlparser.cpp, and tinystr.cpp to your
project or make file. That's it! It should compile on any reasonably
compliant C++ system. You do not need to enable exceptions or
RTTI for TinyXml.


<h2> How TinyXml works.  </h2>

An example is probably the best way to go. Take:
@verbatim
	<?xml version="1.0" standalone=no>
	<!-- Our to do list data -->
	<ToDo>
		<Item priority="1"> Go to the <bold>Toy store!</bold></Item>
		<Item priority="2"> Do bills</Item>
	</ToDo>
@endverbatim

Its not much of a To Do list, but it will do. To read this file 
(say "demo.xml") you would create a document, and parse it in:
@verbatim
	TiXmlDocument doc( "demo.xml" );
	doc.LoadFile();
@endverbatim

And its ready to go. Now lets look at some lines and how they 
relate to the DOM.

@verbatim
<?xml version="1.0" standalone=no>
@endverbatim

	The first line is a declaration, and gets turned into the
	TiXmlDeclaration class. It will be the first child of the
	document node.
	
	This is the only directive/special tag parsed by by TinyXml.
	Generally directive targs are stored in TiXmlUnknown so the 
	commands wont be lost when it is saved back to disk.

@verbatim
<!-- Our to do list data -->
@endverbatim

	A comment. Will become a TiXmlComment object.

@verbatim
<ToDo>
@endverbatim

	The "ToDo" tag defines a TiXmlElement object. This one does not have 
	any attributes, but does contain 2 other elements.

@verbatim
<Item priority="1"> 
@endverbatim

	Creates another TiXmlElement which is a child of the "ToDo" element. 
	This element has 1 attribute, with the name "priority" and the value 
	"1".

Go to the 

	A TiXmlText. This is a leaf node and cannot contain other nodes. 
	It is a child of the "Item" TiXmlElement.

@verbatim
<bold>
@endverbatim

	
	Another TiXmlElement, this one a child of the "Item" element.

Etc.

Looking at the entire object tree, you end up with:
@verbatim
TiXmlDocument				"demo.xml"
	TiXmlDeclaration		"version='1.0'" "standalone=no"
	TiXmlComment			" Our to do list data"
	TiXmlElement			"ToDo"
		TiXmlElement		"Item"		Attribtutes: priority = 1
			TiXmlText		"Go to the "
			TiXmlElement    "bold"
				TiXmlText	"Toy store!"
	TiXmlElement			"Item"		Attributes: priority=2
		TiXmlText			"bills"
@endverbatim

<h2> Documentation </h2>

The documentation is build with Doxygen, using the 'dox' 
configuration file.

<h2> License </h2>

TinyXml is released under the zlib license:

This software is provided 'as-is', without any express or implied 
warranty. In no event will the authors be held liable for any 
damages arising from the use of this software.

Permission is granted to anyone to use this software for any 
purpose, including commercial applications, and to alter it and 
redistribute it freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must 
not claim that you wrote the original software. If you use this 
software in a product, an acknowledgment in the product documentation 
would be appreciated but is not required.

2. Altered source versions must be plainly marked as such, and 
must not be misrepresented as being the original software.

3. This notice may not be removed or altered from any source 
distribution.

<h2> References  </h2>

The World Wide Web Consortium is the definitive standard body for 
XML, and there web pages contain huge amounts of information. I also 
recommend "XML Pocket Reference" by Robert Eckstein and published by 
OReilly.

<h2> Contributors, Contacts, and a Brief History </h2>

Thanks very much to everyone who sends suggestions, bugs, ideas, and 
encouragement. It all helps, and makes this project fun. A special thanks
to the contributors on the web pages that keep it lively.

So many people have sent in bugs and ideas, that rather than list here 
we try to give credit due in the "changes.txt" file.

TinyXml was originally written be Lee Thomason. (Often the "I" still
in the documenation.) Lee reviews changes and releases new versions,
with the help of Yves Berquin and the tinyXml community.

We appreciate your suggestions, and would love to know if you 
use TinyXml. Hopefully you will enjoy it and find it useful. 
Please post questions, comments, file bugs, or contact us at:

www.sourceforge.net/projects/tinyxml

Lee Thomason,
Yves Berquin
*/