JPA datasource/mapping problem

[doit]

Hi,
I'm evaluating SmartGWTEE 2.4 at the moment and I have a question concerning the JPA datasource handling.

I have a tree mapping using the @OneToMany and @ManyToOne annotations.
The entity class could look something like that:

@Entity
public class MyTreeNode implements Serializable {

    private Long id;
    private String name;
    private MyTreeNode parent;
    private List<MyTreeNode> children;

    @Id
    @GeneratedValue
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    @ManyToOne
    public MyTreeNode getParent() {
        return parent;
    }

    public void setParent(MyTreeNode parent) {
        this.parent = parent;
    }

    @OneToMany(cascade = CascadeType.ALL)
    public List<MyTreeNode> getChildren() {
        return children;
    }

    public void setChildren(List<MyTreeNode> children) {
        this.children = children;
    }
}

The datasource

<DataSource ID="tree_DS" serverConstructor="com.isomorphic.jpa.JPADataSource" beanClassName="com.sample.server.MyTreeNode">
    <fields>
        <field name="id" type="integer" hidden="true" primaryKey="true"/>
        <field name="name" type="text" title="Name" required="true"/>
        <field name="parent" type="integer" foreignKey="tree_DS.id"/>
    </fields>
</DataSource>

Now, if I want to create a new Treenode resp. Record on the client I only have the IDs of my entities available.
So if I do something like that:

button.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent clickEvent) {
                com.smartgwt.client.widgets.tree.TreeNode selectedRecord = (com.smartgwt.client.widgets.tree.TreeNode) treeGrid.getSelectedRecord();
                String parentId = selectedRecord == null ? "" : selectedRecord.getAttribute("id");
                com.smartgwt.client.widgets.tree.TreeNode node = new com.smartgwt.client.widgets.tree.TreeNode();
                node.setAttribute("name", "SampleName");
                node.setAttribute("parent", parentId);
                treeGrid.addData(node);
            }
        });

I get the obvious error "Can't convert value of type java.lang.Long to target type com.sample.server.MyTreeNode"


Here's what the request looks like:

{
    values:{
        name:"SampleName",
        parent:"1"
    },
    operationConfig:{
        dataSource:"tree_DS",
        operationType:"add"
    },
    componentId:"isc_TreeGrid_0",
    appID:"builtinApplication",
    operation:"tree_DS_add",
    oldValues:{
        name:"SampleName",
        parent:"1"
    },
    criteria:{
    }
}

Am I missing something here? Or do I have to use DMI and set the Parent entity manually?

Thanks in advance.

[doit]

After looking at the ds-jpa sample project I've noticed some differences in the mapping and I think I've got it working now.

The bold passages were edited.
MyTreeNode.java

@Entity
public class MyTreeNode implements Serializable {

    private Long id;
    private String name;
    private MyTreeNode parent;
    private List<MyTreeNode> children;
    [b]private Long parentId;[/b]

    @Id
    @GeneratedValue
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    @ManyToOne
   [b] @JoinColumn(name = "parentId", referencedColumnName = "parentId", nullable=false, insertable=false, updatable=false)[/b]
    public MyTreeNode getParent() {
        return parent;
    }

    public void setParent(MyTreeNode parent) {
        this.parent = parent;
    }

    @OneToMany(cascade = CascadeType.ALL)
    public List<MyTreeNode> getChildren() {
        return children;
    }

    public void setChildren(List<MyTreeNode> children) {
        this.children = children;
    }
[b]
    public Long getParentId() {
        return parentId;
    }

    public void setParentId(Long parentId) {
        this.parentId = parentId;
    }[/b]
}

tree_DS.ds.xml

<DataSource ID="tree_DS" serverConstructor="com.isomorphic.jpa.JPADataSource" beanClassName="com.sample.server.MyTreeNode">
    <fields>
        <field name="id" type="integer" hidden="true" primaryKey="true"/>
        <field name="name" type="text" title="Name" required="true"/>
        <field name=[b]"parentId"[/b] type="integer" foreignKey="tree_DS.id"/>
    </fields>
</DataSource>

Client-side call:

button.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent clickEvent) {
                com.smartgwt.client.widgets.tree.TreeNode selectedRecord = (com.smartgwt.client.widgets.tree.TreeNode) treeGrid.getSelectedRecord();
                String parentId = selectedRecord == null ? "" : selectedRecord.getAttribute("id");
                com.smartgwt.client.widgets.tree.TreeNode node = new com.smartgwt.client.widgets.tree.TreeNode();
                node.setAttribute("name", "SampleName");
                node.setAttribute([b]"parentId"[/b], parentId);
                treeGrid.addData(node);
            }
        });

I still have to take a closer look at it to fully understand what's going on there, but at least it's working for now. :)

Regards