Oracle JET - How To Reference JavaScript Module in HTML

I will explain how to reference JavaScript module function in Oracle JET HTML. In previous Oracle JET versions, we were using $root to access parent appController module. Syntax $root looks a bit like magic, it is better to reference module through a predefined variable. I will show you how.

Sample app comes with number converter, which helps to format numeric value. For convenience reasons and better reuse, number formatting function is moved to a separate module. Our goal is to call function self.convertNumericValue from converter module inside our module HTML:

Import the converter module into your target module. Make sure to define a variable for the import. Then define the local variable and assign it with the value pointing to the imported module. This will allow calling functions from the imported module, anywhere within our target module:

To demonstrate how it works, I will include a call to format number for the table column. I have defined a table column template for that reason:

Within the template, I'm calling converter (function is called by referencing local variable) to format number:

It works well, the column with salary values is formatted by function from the imported module:

A sample application is available on my GiHub repo.

Oracle JET Model ID Attribute

When building Oracle JET Model/Collection structure to render table, you should be careful defining ID attribute. This attribute must have unique values only, if there will be duplicates in ID, then table rows will be rendered incorrectly.

Take as example below structure for Employees REST endpoint. EmployeId attribute provides unique values and it should be defined as ID for JET model:

Let's try and see what happens when non-unique DepartmentId attribute is set for a key in JET model:

In this case, during data fetch and UI table rendering (specifically when navigating to the next page of the table) - JET runtime for the table will get confused and will fetch all of the records from the backend (definitely, not what we want):

Ok, change it to the proper one - use EmployeeId for the ID in JET model:

The table works as expected:

Lesson learned - make sure to use an attribute with unique values for JET model ID. If there is no single attribute with unique values, the concatenate multiple attributes on the backend to construct a single attribute with unique value.

Source code is available from my GitHub repo.

Report Time Execution Prediction with Keras and TensorFlow

The aim of this post is to explain Machine Learning to software developers in hands-on terms. Model is based on a common use case in enterprise systems — predicting wait time until the business report is generated.

Report generation in business applications typically takes time, it can be from a few seconds to minutes. Report generation requires time, because typically it would fetch and process many records, this process needs time. Users often get frustrated, they don’t know how long to wait until the report is finished and may go away by closing browser, etc. If we could inform user, before submitting the report request — how it long it will take to execute it, this would be great usability improvement.

I have implemented Machine Learning model using Keras regression to calculate expected report execution time, based on training data (logged information from the past report executions). Keras is a library which wraps TensorFlow complexity into simple and user-friendly API.

Python source code and training data is available on my GitHub repo. This code is based on Keras tutorial.