The current eXML version is 0.1.6. It is using expat version 1.0.2

Copyright (c) 1999 Andreas Leitner. eXML is subject to the Eiffel Forum Freeware License.

04/13/1999 - Version 0.1.6
Added eBook sample (Details on it later). The tree based parser now generated attributes of elements. Some bug fixes.

04/08/1999 - Version 0.1.5
Basic implementation of a tree based parser and bugfixes.

04/01/1999
Redesigned web site. Still in work (: Works fine with IE5. Netscape 4.5 on Windows has some problems. Others have not been tested yet. Please send in any comments.

Version 0.1.4:
Linux is now officially supported. Easier installing of eXML.

Version 0.1.3:
eXML now also compiles under SmallEiffel. Redesing of internal classes.

Version 0.1.2:
eXML Redesing of internal classes to enable easier port.

Version 0.1.1:
Many more hooks are supported. Most of the expat API has been encapsulated, but some still need some work to make the features accessible easily. ]]> Download eXML can be downloaded from exml_0_1_6.zip. ]]> Compatibility Eiffel Compiler

• ISE Eiffel 4.2 (or better) on Windows (tested with Visual C++ 6 as backend C-compiler). If you succeed in compiling eXML on Unix/Linux please mail me. I would be happy to inlcude the Linux ACE file in the next release then.
• SmallEiffel -0.78 Beta #3 (or better) on Windows and Linux (tested with Visual C++ 6 resp. gcc (don't ask me which version :) as backend C-compiler)

Libraries

• GOBO

Note on SmallEiffel
Since the SmallEiffel (version -0.78 Beta #3) garbage collectior does not support finalizaion yet, objects of the type XML_PARSER will not free all their memory when beeing collected. I hope that this feature will soon be included, though.

Note on GOBO
There is a bug in the SE version of GOBO (1.3). Replace 'a_buffer' with 'Result' in file "/kernel/spec/se/kl_input_stream_routines.e" in feature 'read_string'. This bug will be corrected in the next release of GOBO. ]]> Installation To install the eXML Library unpack it in a directory of your choice and set the enviroment variable EXML to this directory. Now depending on your platform you need to do the following:

Windows (all):
All the needed libraries come precompiled. The DLL's are stored in the directory %EXML%\expat\bin. Be sure they are in your DLL-loadpath. It's a good idea to put the DLL's in your system directory.

Windows (ISE Eiffel):
There is an extra C-library needed. Please go to the directory %EXML%\compiler_specific\ise\clib and run "nmake makefile.win.msc"

Linux (all):
Go to the directory $(EXML)/expat and run "make". This will generate the needed expat object files, that are needed when compiling an eXML application. ]]> Documentation eXML provides two different type of parsers: an event based parser and a tree based parser. Have a look at http://www.megginson.com/SAX/event.html for a comparsion between event based and tree based XML parsers. The tree based parser (XML_TREE_PARSER) is implemented as a descentant of the event based parser (XML_PARSER). ]]> The Tree Based Parser For the user of the library in most cases the tree based parser will be the better choice. For this reason I will limit the documentation on this topic for now. Objects of the type XML_TREE_PARSER can be feed with a XML document split up in one or more strings. The following example parsers a XML document that is stored completly in a string object of the name `buffer'.

	.
	.
	.
	local
		parser: XML_TREE_PARSER
	.
	.
	.
			-- somewhere the parser must be created (:
		!! parser.make
	.
	.
	.
			-- parse the XML-document
	parser.parse_string (buffer)
			-- and tell the parser that the end of the document has been reached
	parser.set_end_of_file	
	
	if
		not parser.is_correct
	then
			-- whoops! there was an error in the docment.
			-- print out some information about that error
		print ("%N")
		print (parser.last_error_string)
		print (" at ln: ")
		print (parser.last_line_number)
		print (", cl: ")
		print (parser.last_column_number)
		print ("%N")
	else
			-- the document was parsed successfully.
			-- print out the structure of the document
		print (parser.out)
	end
	
	

The parser stores the information contained in the XML-document as a tree consisting of XML_NODES. The following is a inheritance graph of all nodes currently implemented.

The parser inheritance graph itself is presented in the next picture. You see that the tree parser not only inherits from the event based parser, but also from XML_DOCUMENT. Objects of the type XML_DOCUMENT represent a whole XML-document. They have a `root_element' of the type XML_ELEMENT and (in the future will) hold additional information given in the XML-document (i.e. the encoding)

Currently there is not much documentation available about eBook. Have a look at the test data in the directory "/examples/test_data/ebook/input" to see how eBook works.

Watch this space for more information about eBook...

One last note: If you try eBook and worry about it beeing slow, try compiling it with assertion checking turned off !!! ]]> Future eXML is Open Source, it's not only on me to determine.

But now to more (or less) concrete things (:

• Improve the variety of input-types XML_PARSER is able to process. Currently only objects of type STRING are supported.
• The use of UNICODE is suggested by the W3C, but I have no idea how to realize that at the moment.
• To automate the parsing of external enities a compiler and platform independent network library would be needed. Parsing local files can be implemented without and this is likely to be implemented first.
• Various character encodings should be handled.
• Introducing further abstractions to allow different XML-parsers to be hooked in (also a pure Eiffel implementation would be possible).
• Improving the tree bases parser. (Generating objects for start tag parameters, adding features for making the enhance the ease of use)

Finnally as said above this library is Open Source. If you make any improvements or found/fixed a bug I would be happy to hear from you. If you use this library, please let me know what you think of it. Thank you in advance. ]]> Known Bugs Date Description Status 04/08/1999 There are strange XML-errors reported when compiling with ISE. Fixed since version 0.1.6. 04/14/1999 Compiling eBook with SmallEiffel and option "-boost" will result in C-error messages. Seems to be a bug in SmallEiffel. Not fixed. ]]> Notes The files in the directory expar are (unmodified) taken from expat and therefore are subject to the Mozilla Public License Version 1.0.

There is now a mailing list for eXML at www.egroups.com.

• James Clark for writing expat and to Loryn Jenkins for telling me about expat (:
• the authors of SWIG and SWIGEIFFEL. It helped me a lot when porting eXML to SmallEiffel.
• Eric Bezault for providing the great GOBO library
• ISE Eiffel
• the SmallEiffel team
• lot of other people, that helped in the one or the other way in making this project possible.
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