Hi there,
Is there a sample project using many-to-many link table with additional columns?
I need to implement this feature with editable table on Browse screen. If you can help with ideas would be great.
Thank you!
Click tutorial 
Hello, does not really help in case there is many-to-many link table with additional fields.
Hi,
What is the problem, exactly?
I’ve created a small project to demonstrate the simplest example of a many-to-many link table with additional columns. If it’s not your case, please specify your question.
demo.zip (92.7 KB)
Also, you may be interested in this example, too: How do I display One-To-Many and Many-To-Many attribute by strategy? - CUBA.Platform
It contains quite an interesting example of many-to-many relationship.
Hi @shiryaeva!
Thank you for the answer. I cannot open the “demo” project: “Version of Platform used in project (6.9.0.BETA3) not supported.”
I am currently using 6.8.2. Please advise!
Regards!
Hi @shiryaeva!
I will give explanation to the problem I do face with “demo” example you provided.
What I need to do is to put in “Group Editor” screen a table with list of all Customers in this group. In this table “additional field” should be shown as well.
I should be able to add more Customers from this screen and edit their “additional field” from here.
I tried many times but still cannot find a solution. I would appreciate if you can help!
Thank you in advance!
Hi,
You can add an extra datasource to your Group editor and a Customers table bound to it, for example:
<collectionDatasource id="customerGroupsDs"
class="com.company.demo.entity.CustomerGroup"
view="customerGroup-view">
<query>
<![CDATA[select e from demo$CustomerGroup e
where e.group.id = :ds$groupDs]]>
</query>
</collectionDatasource>
<table id="customersTable"
width="100%">
<actions>
<action id="create"/>
<action id="edit"/>
<action id="remove"/>
</actions>
<columns>
<column id="additionalField"/>
<column id="customer.name"/>
</columns>
<rows datasource="customerGroupsDs"/>
<buttonsPanel id="buttonsPanel">
<button id="createButton"
action="customersTable.create"/>
<button id="editButton"
action="customersTable.edit"/>
<button id="removeButton"
action="customersTable.remove"/>
</buttonsPanel>
</table>
This will enable you to add new Customers through adding CustomerGroups.
Hi again,
There is a better solution for your use case:
Add composition attributes that will reference your link table and create a custom action that will enable to select a Customer and create a new link (CustomerGroup entity) in your Group editor.
Data model
- Customer
@Table(name = "DEMO_CUSTOMER")
@Entity(name = "demo$Customer")
public class Customer extends StandardEntity {
@Composition
@OnDelete(DeletePolicy.CASCADE)
@OneToMany(mappedBy = "customer")
protected List<CustomerGroup> customerGroups;
}
- Group
@Table(name = "DEMO_GROUP")
@Entity(name = "demo$Group")
public class Group extends StandardEntity {
@Composition
@OnDelete(DeletePolicy.CASCADE)
@OneToMany(mappedBy = "group")
protected List<CustomerGroup> customerGroups;
}
- CustomerGroup
@Table(name = "DEMO_CUSTOMER_GROUP")
@Entity(name = "demo$CustomerGroup")
public class CustomerGroup extends StandardEntity {
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "CUSTOMER_ID")
protected Customer customer;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "GROUP_ID")
protected Group group;
@Column(name = "ADDITIONAL_FIELD")
protected String additionalField;
}
group-edit.xml:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<window xmlns="http://schemas.haulmont.com/cuba/window.xsd"
caption="msg://editorCaption"
class="com.company.demo.web.group.GroupEdit"
datasource="groupDs"
focusComponent="fieldGroup"
messagesPack="com.company.demo.web.group">
<dsContext>
<datasource id="groupDs"
class="com.company.demo.entity.Group"
view="group-view">
<collectionDatasource id="customerGroupsDs"
property="customerGroups">
</collectionDatasource>
</datasource>
</dsContext>
<dialogMode height="600"
width="800"/>
<layout expand="windowActions"
spacing="true">
<fieldGroup id="fieldGroup"
datasource="groupDs">
<column width="250px">
<field property="name"/>
</column>
</fieldGroup>
<groupBox id="customerGroupsBox"
caption="msg://com.company.demo.entity/Group.customerGroups">
<table id="customerGroupsTable"
height="200px"
width="100%" editable="true">
<actions>
<action id="addCustomer" invoke="addCustomer"/>
<action id="create"/>
<action id="edit"/>
<action id="remove"/>
</actions>
<columns>
<column id="customer"/>
<column id="additionalField" editable="true"/>
</columns>
<rows datasource="customerGroupsDs"/>
<buttonsPanel>
<button action="customerGroupsTable.addCustomer" caption="Add customer"/>
<button action="customerGroupsTable.create"/>
<button action="customerGroupsTable.edit"/>
<button action="customerGroupsTable.remove"/>
</buttonsPanel>
</table>
</groupBox>
<frame id="windowActions"
screen="editWindowActions"/>
</layout>
</window>
GroupEdit.java:
public class GroupEdit extends AbstractEditor<Group> {
@Inject
private Datasource<Group> groupDs;
@Inject
private CollectionDatasource<CustomerGroup, UUID> customerGroupsDs;
@Inject
private Metadata metadata;
public void addCustomer() {
openLookup(Customer.class, items -> {
if (!items.isEmpty()) {
Customer customer = (Customer) items.iterator().next();
CustomerGroup newLink = metadata.create(CustomerGroup.class);
newLink.setCustomer(customer);
newLink.setGroup(groupDs.getItem());
customerGroupsDs.addItem(newLink);
}
}, WindowManager.OpenType.DIALOG);
}
}
You can try this approach in the sample attached:
demo-with-composition.zip (93.5 KB)
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