|
1
|
<!--
|
|
2
|
* Metacatdom.html
|
|
3
|
*
|
|
4
|
* Authors: Jivka Bojilova
|
|
5
|
* Copyright: 2000 Regents of the University of California and the
|
|
6
|
* National Center for Ecological Analysis and Synthesis
|
|
7
|
* For Details: http://www.nceas.ucsb.edu/
|
|
8
|
* Created: 2000 April 5
|
|
9
|
* Version: 0.01
|
|
10
|
* File Info: '$Id: metacatdom.html 3780 2008-04-02 23:28:31Z daigle $'
|
|
11
|
*
|
|
12
|
* October Meeting SDSC, 2000
|
|
13
|
-->
|
|
14
|
<HTML>
|
|
15
|
<HEAD>
|
|
16
|
<TITLE>Metacat</TITLE>
|
|
17
|
<link rel="stylesheet" type="text/css" href="./default.css">
|
|
18
|
</HEAD>
|
|
19
|
<BODY>
|
|
20
|
<table width="100%">
|
|
21
|
<tr>
|
|
22
|
<td class="tablehead" colspan="2"><p class="label">The Metacat DOM</p></td>
|
|
23
|
<td class="tablehead" colspan="2" align="right">
|
|
24
|
<a href="./metacatdb.html">Back</a> | <a href="./metacattour.html">Home</a> |
|
|
25
|
<a href="./clientapi.html">Next</a>
|
|
26
|
</td>
|
|
27
|
</tr>
|
|
28
|
</table>
|
|
29
|
<P>In the Metacat DOM implementation XML documents
|
|
30
|
are disassembled into their composite nodes. All nodes are stored as records
|
|
31
|
in the database tables. The structure of each XML document is preserved
|
|
32
|
by saving the parent-child relationship between the nodes.
|
|
33
|
<ul>
|
|
34
|
<li> Each XML document in the Metacat database starts with one root node of
|
|
35
|
type DOCUMENT. All other nodes in the document are its children.
|
|
36
|
The document node can
|
|
37
|
have multiple COMMENT or PI (processing instruction) nodes and only
|
|
38
|
one ELEMENT node. The element node is the root node of the document and will
|
|
39
|
be pointed to by all of its children.
|
|
40
|
<li> Each node is described as a single record in the <i>xml_nodes</i> table.
|
|
41
|
All nodes have a unique System ID (<i>nodeid</i>). Each node stores
|
|
42
|
the ID of
|
|
43
|
its direct parent (in <i>parentnodeid</i>), the ID of its documents root node
|
|
44
|
(in <i>rootnodeid</i>) and its Document ID (<i>docid</i>).
|
|
45
|
<li> Document attributes (such as docid, doctype, etc.) are stored in
|
|
46
|
the xml_documents table.
|
|
47
|
<li> Unimplemented DOM features:
|
|
48
|
<ul>
|
|
49
|
<li> Node types: Doctype, Entity, EntityReference, Notation.
|
|
50
|
<li> Persistant DOM interface. This would allow a DOM compliant
|
|
51
|
editor to work with an xml document in the database as if it were
|
|
52
|
in memory.
|
|
53
|
<li>Object Oriented representation of each node.
|
|
54
|
</ul>
|
|
55
|
</ul>
|
|
56
|
<P> <img alt="Entity Relationship Diagram of the Metacat DOM" src="metacatdom.jpg">
|
|
57
|
|
|
58
|
<br>
|
|
59
|
<a href="./metacatdb.html">Back</a> | <a href="./metacattour.html">Home</a> |
|
|
60
|
<a href="./clientapi.html">Next</a>
|
|
61
|
</BODY>
|
|
62
|
</HTML>
|
|
63
|
|
