Auto-Create An Entity With Creation of A Different Entity

Support
#1

Hi good people,

I need your help in designing a scenario I have…

  1. I have a person registration screen (Person Entity)
  2. Invoice screen (Invoice Entity)
  3. Invoice lines (Invoice Lines Entity)
  4. Inventory screens (Inventory Entity)

On inventories, I have the following attributes name, cost with a line item called registration fee - 100/-

What I need to achieve…

On new registration of person, I need to automatically create an invoice for the registration fee for that person.

I just need to refresh my creativity on how I can achieve this.

Let me here your thoughts.

Regards,
Kenince

#3

Hi Kenince,

New entity instances can be created with metadata.create() method, for example, in the postCommit() method of the entity editor.

For example:

person-edit.xml

. . .
    <dsContext>
        <datasource id="personDs"
                    class="com.company.demo.entity.Person"
                    view="person-full">
            <collectionDatasource id="invoicesDs"
                                  property="invoices">
                <collectionDatasource id="linesDs"
                                      property="lines"/>
            </collectionDatasource>
        </datasource>
    </dsContext>
. . .

PersonEdit.java

public class PersonEdit extends AbstractEditor<Person> {
    @Inject
    private Metadata metadata;
    @Inject
    private Datasource<Person> personDs;

    private boolean isNew = false;
    private static final String REG_FEE = "Registration fee";
    private static final BigDecimal REG_FEE_COST = BigDecimal.valueOf(100);

    @Override
    protected void initNewItem(Person item) {
        isNew = true;
    }

    private void addRegistrationFee(Person person) {
        Invoice invoice = metadata.create(Invoice.class);
        invoice.setDate(new Date());
        invoice.setPerson(person);

        InvoiceLine line = metadata.create(InvoiceLine.class);
        line.setFee(REG_FEE);
        line.setCost(REG_FEE_COST);
        line.setInvoice(invoice);

        List<InvoiceLine> lines = new ArrayList<>();
        lines.add(line);
        invoice.setLines(lines);

        List<Invoice> invoiceList = new ArrayList<>();
        invoiceList.add(invoice);
        personDs.getItem().setInvoices(invoiceList);
        personDs.commit();
    }

    @Override
    protected boolean postCommit(boolean committed, boolean close) {
        if (isNew && committed)
            addRegistrationFee(getItem());
        return super.postCommit(committed, close);
    }
}

I’ve created a small demo app that illustrates this approach: demo.zip (121.1 KB)

I would also recommend taking a look at the Modeling Problem Domain section of our cookbook and the related forum topics:

2 Likes
#4

Hello,

This solution works only if we want to create new instances (from Edit Entity x create automatically a new record in Entity y). But how can we proceed if we want to Edit the newly created Entity x (some specific attribute)? It must also reflected in (the same) Entity y.

Regards,
-n