App Component - using entities stored in app component database

matt.keeble · December 17, 2019, 5:42pm

Hi all,

Apologies if this has already been answered but I couldn’t quite see anything which directly answered my question.

I have 2 projects, A & B.

I would like to use B as an add-on module for A. (I am assuming that is what app-components are supposed to be used for.)

I would like the screens and classes to be carried over from B (as they currently are as an app-component) but I want to store the entities that are created from project B screens in database B. Is that possible? (Currently they get stored in database A by default)

Thank you for any clarification and help.

Regards

Matt

albudarov · December 19, 2019, 1:23pm

Hi,

Yes, it is possible.

You have to make the following changes in project files. I have created sample projects as a proof-of-concept.

In addon (“gps” project):
make changes in app compoenent descriptor (app-component.xml).
Comment out this export line:

    <module name="global" blocks="*">
        <artifact name="gps-global" appJar="true"/>

        <!--<property name="cuba.persistenceConfig" value="+com/company/gps/persistence.xml"/>-->
        <property name="cuba.metadataConfig" value="+com/company/gps/metadata.xml"/>
        <property name="cuba.viewsConfig" value="+com/company/gps/views.xml"/>
    </module>

Because it is this line that forces project to put addon’s entities to main data store.

Create “gps” addon database from gps add-on project.
Install gps app-component (to local maven).
In project A (“gis-with-gps” sample) - create new additional data store “gps” with the same name / URL as just created gps database.
In project gis-with-gps - change additional datastore’s persistenceConfig application property in all modules (core, web, portal), adding addon’s persistence.xml:

cuba.persistenceConfig_gps = +com/company/gis/gps-persistence.xml com/company/gps/persistence.xml

That’s it.
Run main application, gps entities and screens are loaded and displayed.
Limitations.

You have to attach additional datastore manually, it can not be automatically exported by add-on.
CUBA 7.1 does not support automatic DB schema management for additional datastores, so you will have to update addon’s DB schema manually.
Upcoming CUBA 7.2 will add such possibility: Execute DDL scripts for additional data stores · Issue #2332 · cuba-platform/cuba · GitHub

gps-component.zip (79.5 KB)
gis-with-gps.zip (73.4 KB)

matt.keeble · December 19, 2019, 1:36pm

Thank you very much for your help Alex I shall give that a go.

Much appreciated,

Regards

Matt