[Cocoon Wiki] New: NewbieGuideToOJB2

[do...@cocoon.apache.org]

   Date: 2004-07-30T08:02:26
   Editor: JooseVettenranta <jo...@iki.fi>
   Wiki: Cocoon Wiki
   Page: NewbieGuideToOJB2
   URL: http://wiki.apache.org/cocoon/NewbieGuideToOJB2

   copy & paste from my site

New Page:

==  Page title (cookbook approach, tutorial , ...) ==
- TARGET-AUDIENCE: '''*beginner*''' advanced expert[[BR]]
- COCOON-RELEASES: 2.0.3, 2.0.4[[BR]]
- DOCUMENT-STATUS: '''*draft*''' reviewed released[[BR]]
----

===Introduction===


This page is my setup and adventure to get cforms work with OJB and 1:n  relationships. After all this is working, this could be used as a template to  create tutorial / something to help others to do the same thing.


Status




OJB stuff seems to work ok, because the test-script executes ok.

UPDATE works when I added hidden field with id see template.

DELETE works.



Everything is working




TODO


Database

CREATE TABLE parent (
 id SERIAL,
 name VARCHAR(50),
PRIMARY KEY (id));

CREATE TABLE childs (
 id SERIAL,
 parent_id INTEGER NOT NULL,
 name VARCHAR(20),
PRIMARY KEY(id),
FOREIGN KEY(parent_id) REFERENCES parent (id));



So we have one-to-many (1:n) connection between parent and child.


So if we add new records, we first have to add record to table A and afterthat records to table childs.


Java classes


parent

package net.vettenranta;

import java.util.ArrayList;
import java.util.Collection;

import java.io.Serializable;

public class Parent implements Serializable {
        private int id;
        private Collection childs = new ArrayList ();
        private String name;

        public int getId () { return id; }
        public void setId (int id) { this.id = id; }

        public Collection getChilds () { return childs; }
        public void setChilds (Collection childs ) { this.childs = childs; }
        public void addChild (Child child) {
                child.setParent (this);
                this.childs.add (child);
        }
        public String getName () { return name; }
        public void setName (String name) { this.name = name; }
}



child

package net.vettenranta;

import java.io.Serializable;

public class Child implements Serializable {
        private int id;
        private Parent parent;
        private String name;

        public int getId () { return id; }
        public void setId (int id) { this.id = id; }

        public Parent getParent () { return parent; }
        public void setParent (Parent parent) { this.parent = parent; }

        public String getName () { return name; }
        public void setName (String name) { this.name = name; }
}



DAO

package net.vettenranta;

import java.util.Iterator;

import javax.jdo.PersistenceManager;
import javax.jdo.Transaction;

import org.apache.cocoon.ojb.jdo.components.JdoPMF;
import org.apache.ojb.broker.Identity;
import org.apache.ojb.broker.PersistenceBroker;
import org.apache.ojb.broker.PersistenceBrokerFactory;
import org.apache.ojb.broker.util.ObjectModificationDefaultImpl;

public class DAO {
        // requires lot's of comments
        public Parent retrieve(Parent bean, JdoPMF pmf) {
                PersistenceManager persistenceManager = pmf.getPersistenceManager();
                PersistenceBroker broker = PersistenceBrokerFactory.defaultPersistenceBroker();
                Query query = new QueryByIdentity(bean);
                Parent result = (Parent) broker.getObjectByQuery(query);
                broker.close();
                return result;
        }

        public void insert(Parent bean, JdoPMF pmf) {
                PersistenceManager persistenceManager = pmf.getPersistenceManager();
                PersistenceBroker broker = PersistenceBrokerFactory.defaultPersistenceBroker();
                broker.beginTransaction();
                broker.store(bean);
                broker.commitTransaction();
                broker.close();
        }

        public void remove(Parent bean, JdoPMF pmf) {
                PersistenceManager persistenceManager = pmf.getPersistenceManager();
                PersistenceBroker broker = PersistenceBrokerFactory.defaultPersistenceBroker();
                broker.beginTransaction();
                broker.delete(bean);
                broker.commitTransaction();
                broker.close();
        }


        public void update(Parent bean, JdoPMF pmf) {
                PersistenceManager persistenceManager = pmf.getPersistenceManager();
                PersistenceBroker broker = PersistenceBrokerFactory.defaultPersistenceBroker();
                Iterator it = bean.getChilds().iterator();

                broker.beginTransaction();
                broker.store(bean, ObjectModificationDefaultImpl.UPDATE);
                broker.commitTransaction();
                broker.close();
        }

}



package.jdo

<?xml version="1.0"?>
<!DOCTYPE jdo SYSTEM "file:/javax/jdo/jdo.dtd">

<jdo>
        <package name="net.vettenranta">
                <class name="Parent" identity-type="datastore">
                        <field name="id" persistence-modifier="persistent">
                                <extension vendor-name="ojb" key="column" value="ID"/>
                        </field>
                        <field name="name" persistence-modifier="persistent">
                                <extension vendor-name="ojb" key="column" value="NAME"/>
                        </field>
                        <field name="childs" embedded="true">
                                <collection embedded-element="true" />
                        </field>
                </class>
                <class name="Child" identity-type="datastore">
                        <field name="id" persistence-modifier="persistent">
                                <extension vendor-name="ojb" key="column" value="ID"/>
                        </field>
                        <field name="parent" persistence-modifier="persistent">
                                <extension vendor-name="ojb" key="column" value="PARENT_ID"/>
                        </field>
                        <field name="name" persistence-modifier="persistent">
                                <extension vendor-name="ojb" key="column" value="NAME"/>
                        </field>
                </class>
        </package>
</jdo>



Enhancing the classes


I have untarred jdo to my homedirectory.


Manually


This will place enhanced binaries to output directory. It will create that directory.

$ export CLASSPATH=~/jdo-1_0_1-ri/jdo.jar:~/jdo-1_0_1-ri/jdori-enhancer.jar:~/jdo-1_0_1-ri/jdori.jar:.
$ java com.sun.jdori.enhancer.Main -d output package.jdo net/vettenranta/Parent.class net/vettenranta/Child.class



repository.xml

<descriptor-repository version="1.0" isolation-level="read-uncommitted">
        <jdbc-connection-descriptor jcd-alias="test" default-connection="true" platform="PostgreSQL" subprotocol="postgresql">
                <sequence-manager className="org.apache.ojb.broker.util.sequence.SequenceManagerNextValImpl"/>
        </jdbc-connection-descriptor>
        <class-descriptor class="net.vettenranta.Parent" table="PARENT">
                <field-descriptor name="id" primarykey="true" nullable="false" default-fetch="true" autoincrement="true" column="ID" sequence-name="parent_id_seq" jdbc-type="INTEGER"/>
                <field-descriptor name="name" default-fetch="true" column="NAME" jdbc-type="VARCHAR"/>
                <collection-descriptor name="childs" element-class-ref="net.vettenranta.Child" auto-retrieve="true" auto-delete="true" auto-update="true">
                        <inverse-foreignkey field-ref="parent_id"/>
                </collection-descriptor>
        </class-descriptor>
        <class-descriptor class="net.vettenranta.Child" table="CHILDS">
                <field-descriptor name="id" primarykey="true" nullable="false" default-fetch="true" column="ID" jdbc-type="INTEGER" autoincrement="true" sequence-name="childs_id_seq" />
                <field-descriptor name="parent_id" nullable="false" default-fetch="true" column="PARENT_ID" jdbc-type="INTEGER" access="anonymous"/>
                <field-descriptor name="name" default-fetch="true" column="NAME" jdbc-type="VARCHAR"/>
                <reference-descriptor name="parent" class-ref="net.vettenranta.Parent">
                        <foreignkey field-ref="parent_id" />
                </reference-descriptor>
        </class-descriptor>
</descriptor-repository>



Test-script (in cocoon flowscript)


This script works. So It's pretty safe to say that everything should be ok.

function test () {
        var factory = cocoon.getComponent(Packages.org.apache.cocoon.ojb.jdo.components.JdoPMF.ROLE);
        var bean = new Packages.net.vettenranta.Parent ();
        var child;
        var dao = new Packages.net.vettenranta.DAO ();
        var id;
        var iterator;
        // 1.
        // let's make a new bean with 1 child
        bean.setName ('Dad 1');
        child = new Packages.net.vettenranta.Child ();
        child.setName ('Child 1');
        bean.addChild (child);

        // 2.
        // let's save it
        dao.insert (bean, factory);

        // 3.
        // let's retrieve it from database
        id = bean.getId();
        bean = new Packages.net.vettenranta.Parent ();
        bean.setId(id);
        bean = dao.retrieve(bean, factory);
        
        iterator=bean.getChilds().iterator();

        while (iterator.hasNext()) {
                child = iterator.next();
                child.setName ('Child XXX');
        }

        // 4.
        // let's modify the bean

        bean.setName ('Dad 2');
        child = new Packages.net.vettenranta.Child ();
        child.setName ('Child 2');
        bean.addChild (child);

        // let's save it to the database
        dao.update (bean, factory);

        // and remove it from database
        dao.remove (bean, factory);

        cocoon.releaseComponent(factory);

        cocoon.redirectTo ("add.html");
}



CForms flowscript



        bean.setId (id);
        bean = dao.retrieve (bean, factory);
        form.load(bean);
        form.showForm("forms/edit.html"); // EVERYTHING OK SO FAR
        form.save(bean);
        dao.update (bean, factory);





CForms binding

<fb:context xmlns:fb="http://apache.org/cocoon/forms/1.0#binding" path="/" >

 <fb:value id="id" path="id" direction="load"/>
 <fb:value id="name" path="name" />

  <fb:repeater id="childs"
               parent-path="."
               row-path="childs">

    <fb:identity>
      <fb:value id="id" path="@id"/>
    </fb:identity>

    <fb:on-bind>
      <fb:value id="id" path="id"/>
      <fb:value id="name" path="name"/>
    </fb:on-bind>

    <fb:unique-row>
      <fb:unique-field id="id" path="id"/>
    </fb:unique-row>


    <fb:on-delete-row>
      <fb:delete-node />
    </fb:on-delete-row>

    <fb:on-insert-row>
      <fb:insert-bean
        classname="net.vettenranta.Child"
        addmethod="addChild"/>
    </fb:on-insert-row>
  </fb:repeater>
</fb:context>



CForms forms

<fd:form
  xmlns:fd="http://apache.org/cocoon/forms/1.0#definition"
  xmlns:i18n="http://apache.org/cocoon/i18n/2.1">

 <fd:widgets>
  <fd:field id="id">
   <fd:datatype base="integer" />
  </fd:field>
  <fd:field id="name">
   <fd:datatype base="string" />
   <fd:label>Name</fd:label />
  </fd:field>

  <fd:repeater id="childs">
   <fd:widgets>

   <fd:field id="id">
    <fd:datatype base="integer" />
   </fd:field>

    <fd:field id="name" required="true">
      <fd:datatype base="string">
       <fd:validation>
        <fd:length min="3"/>
       </fd:validation>
      </fd:datatype>
      <fd:label>Name</fd:label>
    </fd:field>

    <fd:booleanfield id="select">
     <fd:label>Select</fd:label>
    </fd:booleanfield>

   </fd:widgets>
  </fd:repeater>
  <fd:repeater-action id="addchild" action-command="add-row" repeater="childs">
   <fd:label>New child</fd:label>
  </fd:repeater-action>
  
  <fd:repeater-action id="removechild" action-command="delete-rows" repeater="childs" select="select">
   <fd:label>Remove child</fd:label>
  </fd:repeater-action>
 </fd:widgets>
</fd:form>




CForms template


CForms template file has to have (in row-repeater)
<fi:widget id="id"><fi:styling type="hidden"><fi:widget>




Software

ojb 1.0.rc6
jdo 1.0.1-ri (sun)
IBM Java2 1.4.1
Cocoon 2.1.5.1
Postgresql 7.3.4-3.rhl9
postgresql-jdbc-7.3.4-3.rhl9
redhat 9

----
===  page metadata ===
- AUTHOR:[[BR]]
- AUTHOR-CONTACT: mailto:author@site.com[[BR]]
- REVIEWED-BY:[[BR]]
- REVIEWER-CONTACT:[[BR]]