xml-dev - RE: [techspace] Re: Questions related to XML

["Falk, Alexander" <falk@icon.at>]

ad 1)

yes, the XML grammar is specified in EBNF (extended backus naur form) in the original XML 1.0 specification (http://www.w3.org/TR/1998/REC-xml-19980210#sec-notation), but the individual lines of the EBNF are scattered through the specs. For a more condensed version, please download our XML editor XML Spy (http://www.xmlspy.com) which uses an external EBNF file to drive its parser, so you can simply take the file "gra_xml.txt" as a starting point after installing our software.

 

ad 2)

XML is defined as a Unicode compliant document, so the XML "keywords" (or more correctly: element names) can come from almost any other character set. If you are interested, I have collected numerous international XML example documents that contain korean, japanes, russian, thai, etc. element names.

 

ad 3)

two different answers:

a) if your document does not refer to a DOCTYPE (either internally or to an external DTD file) and it is well-formed, then it is also considered valid

b) if you include a DOCTYPE that defines only <!ENTITY ...> rules, but not <!ELEMENT ...> constrains, then your document will also be not imposing any restrictions and be valid

 

ad 4)

no, a document can only refer to one external DTD file. However, an external DTD can then include several other "partial" DTD files, so you can easily separate your document type into smaller chunks and put them together individually for each XML file depending on the particular needs. The key is to use "external entities" in the DTD that are then resolved by including an external file.

 

ad 5)

yes, you can also define DOCTYPEs that declare elements recursively. This is OK and is in fact also used in many popular DTDs (e.g. XHTML 1.0)

 

Sincerely,

 

Alexander Falk

... Icon Informations-Systeme GmbH
... makers of the XML Spy editor (http://www.xmlspy.com)
... ALEXANDER FALK
... President, CEO
... http://www.icon.at/falk

-----Original Message-----
From: V P Krishnan [mailto:vilayanur.krishnan@intelligroup.com]
Sent: Friday, January 07, 2000 2:41 AM
To: xml-dev@ic.ac.uk
Subject: FW: [techspace] Re: Questions related to XML

We had the following questions that came up during our internal discussions. Would appreciate anyone taking time for an answer to Q1 through Q4.

 

Thanks

vp

-----Original Message-----
From: Muthu Kuttalingam [mailto:muthu.kuttalingam@intelligroup.com]
Sent: Thursday, January 06, 2000 6:30 PM
To: techspace@egroups.com
Subject: [techspace] Re: Questions related to XML

The following XML is well-formed according to XML Spy 2.5 an XML editor. So I guess, the answer to question number 5 is yes.

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

<test>

    <test>

        <test>This is a test</test>

   </test>

</test>

-----Original Message-----
From: kaustubh.kunte [mailto:kaustubh.kunte@intelligroup.com]
Sent: Wednesday, January 05, 2000 9:46 PM
To: techspace@egroups.com
Subject: [techspace] Questions related to XML

Here are the list of questions which came up during XML discussion. If you find an answer to any of these,

please do share it with the techspace community.

 

1. Can XML grammar be represented in Backus Naur format ( BNF ) .

2. Should XML keywords be always represented in a specific ASCII format or can you use different character set .

3. How to define a NULL DTD. ie a DTD which specifies no constraints. This questions came up because a DTD

is required for a document to be valid. So can we define a NULL DTD which will effectively treat all well formed XML documents

as valid documents.

4.Is there a way of declaring multiple external dtd's in the document type declaration ?

5. Can a child element have same name as the parent element ?

 

Jai XML !!