Project

General

Profile

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

    
(26-26/54)