Failure reading parameter 'selected' of component tynamo/PropertyEditBlocks:palette_set

I'm experiencing tynamo model module (org.tynamo:tapestry-model-web:0.3.1:jar) over Tapestry, and I'm facing an issue that I can't handle.

I've got two entities Client and Contract. Obviously, a client has many contracts :

Contract

@Entity
@BeanModels({ @BeanModel(reorder = "id") })
public class Contract {

    [...]

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="contract_id")
    public Long getId() {
        return id;
    }

    /**
     * @return the client
     */
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "client_id", nullable = true)
    public Client getClient() {
        return client;
    }

Client

@Entity
@BeanModels({ @BeanModel(reorder = "id") })
public class Client{

    [...]

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "client_id")
    public Long getId() {
        return id;
    }

    /**
     * @return the contracts
     */
    @OneToMany(cascade = { CascadeType.ALL })
    public List<Contract> getContracts() {
        return contracts;
    }

All is ok when I try to create a new client if I exclude Contract with

@BeanModels({ @BeanModel(exclude = "contrats") })

But if I try to add one without excluding contracts I get the following exception :

ERROR] pages.Add Render queue error in SetupRender[tynamo/PropertyEditBlocks:palette_set]: Failure reading parameter 'selected' of component tynamo/PropertyEditBlocks:palette_set: org.apache.tapestry5.ioc.internal.util.TapestryException
org.apache.tapestry5.ioc.internal.util.TapestryException: Failure reading parameter 'selected' of component tynamo/PropertyEditBlocks:palette_set: org.apache.tapestry5.ioc.internal.util.TapestryException [at classpath:org/tynamo/pages/PropertyEditBlocks.tml, line 39]
    at org.apache.tapestry5.internal.structure.ComponentPageElementImpl$AbstractPhase.invoke(ComponentPageElementImpl.java:153)
    at org.apache.tapestry5.internal.structure.ComponentPageElementImpl$SetupRenderPhase.render(ComponentPageElementImpl.java:181)
    at org.apache.tapestry5.internal.services.RenderQueueImpl.run(RenderQueueImpl.java:72)
    at org.apache.tapestry5.internal.services.PageRenderQueueImpl.render(PageRenderQueueImpl.java:124)
    at $PageRenderQueue_419b37801cb0d.render(Unknown Source)
    at $PageRenderQueue_419b37801cb0c.render(Unknown Source)

From my understanding of Palette component, that means the default selected values that should be present ... are not ! What is exact because there is no default value !

If I add a client directly in the database (MySQL) and don't exclude this field from my entity, I'm able to show and edit it without any problem, but still issue on adding a new one.

What did I missed ?

Solution

Just make sure your contract list has always a non-null value.

@Entity
@BeanModels({ @BeanModel(reorder = "id") })
public class Client{

    private List<Contract> contracts = new ArrayList<Contract>();

    @OneToMany(cascade = { CascadeType.ALL })
    public List<Contract> getContracts() {
        return contracts;
    }

[...]

}

BTW, careful with the bidirectional relationship between client and contract. In this case I think you are trying to map two sides of the same relationship but instead you are mapping two different relationships. Bidirectional relationships are always tricky, but that's for another question.