Difference between revisions of "EclipseLink/Examples/DBWS/DBWSIntermediateAttribute"

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In the <tt>eclipselink-dbwsutils.jar</tt>, there are built-in transformers that form a [http://en.wikipedia.org/wiki/Chain-of-responsibility_pattern <i>Chain-of-Responsibility</i>]
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In the <tt>eclipselink-dbwsutils.jar</tt>, the built-in transformers form a [http://en.wikipedia.org/wiki/Chain-of-responsibility_pattern <i>Chain-of-Responsibility</i>]
 
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[[Image:NCTChainOfResponsibility.png|650px]]
 
[[Image:NCTChainOfResponsibility.png|650px]]
 
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<br clear="all"/>
 
 
In the <tt>o.e.p.tools.dbws.NamingConventionTransformer</tt> services file, the transformer chain is listed in order:
 
In the <tt>o.e.p.tools.dbws.NamingConventionTransformer</tt> services file, the transformer chain is listed in order:
 
<source lang="text" enclose="div">
 
<source lang="text" enclose="div">

Revision as of 13:15, 3 June 2009

Naming Convention for schema elements

As seen in the Basic Table example, the DBWSBuilder-generated eclipselink-dbws-schema.xsd file derives <element-tag> names from the Database table metadata:

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:xsd="http://www.w3.org/2001/XMLSchema"
 >
  <xsd:complexType name="empType">
    <xsd:sequence>
      <xsd:element name="empno" type="xsd:int" xsi:nil="false"/>
      <xsd:element name="ename" type="xsd:string" xsi:nil="true"/>
      <xsd:element name="job" type="xsd:string" xsi:nil="true"/>
      <xsd:element name="mgr" type="xsd:int" minOccurs="0" xsi:nil="true"/>
      <xsd:element name="hiredate" type="xsd:dateTime" xsi:nil="true"/>
      <xsd:element name="sal" type="xsd:decimal" xsi:nil="true"/>
      <xsd:element name="comm" type="xsd:int" minOccurs="0" xsi:nil="true"/>
      <xsd:element name="deptno" type="xsd:int" xsi:nil="true"/>
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>

Converting the database metadata into the names of <element-tag>'s is the job of o.e.p.tools.dbws.NamingConventionTransformer's

public interface NamingConventionTransformer {
 
    public enum ElementStyle {
        ELEMENT, ATTRIBUTE, NONE
    };
 
    public String generateSchemaName(String tableName);
 
    public String generateElementAlias(String originalElementName);
 
    public ElementStyle styleForElement(String originalElementName);
}

In the eclipselink-dbwsutils.jar, the built-in transformers form a Chain-of-Responsibility NCTChainOfResponsibility.png
In the o.e.p.tools.dbws.NamingConventionTransformer services file, the transformer chain is listed in order:

eclipselink-dbwsutils.jar
|  
+---META-INF
|   |   MANIFEST.MF
|   |  
|   \---services
|           org.eclipse.persistence.tools.dbws.NamingConventionTransformer
            contains 3 lines:
              org.eclipse.persistence.tools.dbws.ToLowerTransformer
              org.eclipse.persistence.tools.dbws.TypeSuffixTransformer
              org.eclipse.persistence.tools.dbws.SQLX2003Transformer

=== Changing an <element-tag> to an "attrib It is possible to change an <element-tag> to an "attribute" with a custom transformer: