Re: JDOM cool

From: Joe D Willliams (JOEDWIL@earthlink.net)
Date: Mon Aug 14 2000 - 01:44:33 PDT


Eric>
> A DOM is like, UGLY. It's got element nodes, and
> then nodes under that for text, CDATA, attributes.
>

How about this?
the DOM, Document Object Model, is
specially designed to deal with XML documents.
In XML a document is made up of one or more elements.
An element has a name, zero or any number of attributes,
and may include content.

For example, an element may be represented as:

<nameSpace:tagname nameSpace:attrName="string" ...>
 Content
</nameSpace:tagname>

or

<nameSpace:tagname nameSpace:attrName="string" ... />

The first form is called an element and
the second form is called an empty element.
  
A simple example of an element is:
<p>Some Content</p>
and a simple example of an empty element is:
<img src="apic.jpg" />

The tagName defines a unique element or a class of elements.
Each attribute has a name and a value.
Especially for HTML, the general function of each attribute is to
describe certain aspects of the content.
The nameSpace prefix adds the ability to define
the structure, content and behavior of
an otherwise identical tagName or attrName with respect
to a particular namespace.
In simplist form, Content can be plain text.
Importantly, the Content of an element can be other
elements and empty elements in a parent-child relationship.

A document made up of these elements and attributes
is described by a separate file, referenced by the document.
For HTML, XHTML, and XML this is called a DTD, Document Type Definition,
which can define certain characteristics of the
elements, attributes, and content, including hierarchy.
The DTD helps the parser construct the document tree,
a hierarchal mapping of elements, attributes, and content,
and also do some level of validation of attribute and content datatypes.
Full XML implementations use an XML Schema
to allow complete validation of document structure
including element hierarchy, attribute inheritance, and
content and attribute datatypes with respect to
a particular namespace.

The core DOM provides standardized API for
the browser, for Java, and for ECMAScript
to get and set elements, attributes, and content,
and also provides an event model to allow interaction with
document structure, content, and behaviors.
The HTML DOM adds interactivity to a certain set of elements
and attributes comprising a HTML document.
The CSS DOM adds simplified access to attributes
by an external 'style' sheet.
  
For an compliant browser, the document is 'live'.
This means that the DOM allows immediate update of the
rendered document content, structure, and behavior
when elements, attributes, or content in the document
and/or rendering rules in the associated style sheet are changed.
 
The DOM design permits access to the document either for
live rendering, by a streaming event model, by query,
or combinations of these.
The first case is typical of a browser environment,
the second where programmed actions are executed
in response to the presence of certain
tagNames or attribute values in the stream,
and the third when the XML file is simply serving as a
data base.

The concept of the style sheet has evolved to the idea
of transforming the document from one form to another.
For example, XSLT provides a standardized, algorithmic
method to transform the structure, content, and behavors
of one document to another document that has different
structure, content and behaviors.
For example, XSLT should provide a method of converting
an e-mail file to an XML document.

I think I've got most of that correct, but of course there is more.
Please excuse me if I repeat myself as I try to restate the
current implemetation idea.

A first step is an application that gives the ability to
archive standard e-mail messages in a standardized XML form.
A method to view the archive contents is provided.

Next, I want to retrieve one of these documents and view it
in an environment that allows me to copy and paste an element
or part of an element from it into another working document,
along with my own comments and links.
The elements taken from the original document maintain
links back to the original document so I can easily find the
original source of the information.

Finally, when the content of the document I am working on is ready,
I can convert it to a standard e-mail form for distribution and archive.

Does this descibe this current step in this OHS development?

Thank You and Best Regards,
Joe



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