In the last couple of years, customers and partners want to use JavaScript based UI development, and want tools used by Oracle to maintain the business continuity and UI. Oracle released JET to help customers, especially if they are working on the Oracle platform and looking to leverage things like the Oracle Alta UI, Oracle Redwood UI or REST services exposed from Oracle SaaS applications.
In this context, one of our customers started moving Oracle ADF applications and functionalities to the all new VBCS.
Below are some of the challenges we faced while migrating the ADF applications to VBCS:
Development of Pagination for Tables
As traditional pagination looks simplified and easy to navigate, customers have preferred it over the new load To Scroll tables and for this Oracle has reintroduced the Paginated Tables, yet aren’t fully supported and rebuilt in OJET. Our customer was looking for the same and this could be archived by creating Pagination Data provider on Array Data Provider, using sample code:
Exposing database
Oracle REST Data Services is a Java Enterprise Edition (Java EE), or a middle tier like OIC can also be used for data extraction and handling. But ORDS provides enhanced security, file caching features, and support to Restful Web Service. ORDS has a feature of Auto REST and PLSQL Gateway, as security and data privacy are concerns in the digital world. It is best to expose SQL queries via PLSQL than enabling the whole database table via Auto REST for use in the application.
Example:
The SQL queries are written inside the handler block, which is linked to a particular template and a module with the schema of Database.
In the above example, there are four parts:
- SQL Query (SELECT * FROM emp)
- Template: Employees
- Module: rest
- Schema:’USERTEST1′
And similarly, other CRUD Operations can also be defined for use in Applications.
Migration of applications
While migrating ADF applications from development environment to production, there is only movement of tables, view query, sequences etc. For movement ORDS REST, Objects needs to be extracted and recompiled into the production environment.
Performance tips
OJET Data provides collections, but ADP and SDP are most prominently supported by objects e.g.,tables, list etc.
As per the above table, the data provider types can be used as per requirement and none are taken for ADF as an LOV as directly linked to the component via SQL.
Read Files via JavaScript
Bulk loading of data is often required by the business e.g., Bulk Hiring, Bulk Transfers of employee between department or entities etc.
VBCS (OJET) is client facing so bulk uploading can be processed in Back End API or in client browser. There are advantages as well as disadvantage of it.
Advantages of Using JavaScript:
- The status of data can be seen shown before data is inserted into DB for further processing.
- Parsing of Data by JavaScript is fast as compared by Backend API
- If Data status is errored, they can be can easily removed and reuploaded.
- UI is more modern and reflect present HTML standards
Disadvantage:
- Dataset greater than 1000 rows can take more time to process than traditional ADF Application and should be broken down into smaller sets of 200 or 500 for quick turnaround.
When creating application on VBCS, the business must have a long term outlook. This will greatly help the design and usage of the application. For more details on creating and enhancing VBCS applications, connect with us.