A (software) design pattern is a general, reusable solution to a commonly occurring problem withing a given context. Christoper Alexander inspired the Gang of four to apply pattern to software and enumerate 23 classic software pattern.

This article discusses how to use some of them in the context of Apex controllers.

The context: Same same, but different

You are creating an application to support construction on force.com that will serve multiple countries. Part of the requirements is to compute a risk score for any given project. While ISO standards form the foundation of the assessment, each jurisdiction has some specialties that alter the logic eventually.

This is just one of the requirements, you have many more that follow the pattern Same Same - But different.

Patterns used

• Interface based programming
• Metadata driven application design
• Facade pattern
• Factory pattern

Besides those, you want to know Apex Enterprise Patterns. Go Trailhead and learn

On December 13 Salesforce announced Lightning Web Components (LWC) a new way to build components on the Salesforce platform. Here is my take.

Expanding Lightning Family

"Lightning" serves now as a family name for modern Salesforce development. LWC are the latest family members. We now have:

• Lightning Platform: the runtime environment
• Lightning Design System: providing the visuals
• The Aura Framework: Implementing components for lightning
• ng-lightning: Angular components using the Lightning Design System - a open source contribution, not affiliated with commercial Salesforce
• Lightning React: React components using the Lightning Design system
• Last not least: Lightning Web Components (LWC)

The linked blog entries explain the rationale, so check them out.

Same but different

The look and feel doesn't change, the way you code them does. For now SFDX, Visual Studio Code and the Salesforce Extension Pack are to goto tools for the Spring 2019 release.

Instead of up to 8 files you only need 4. For one: all JavaScript (3 files) now lives in one ES6 JS file and we don't have an auradoc or svg file for now

Co-existence

Existing Aura based components will continue to work and will even allow to contain LWC components.

What you can't do is putting Aura components inside LWC. So your transition to LWC is bottom-up, not top-down

A recent requirement from a customer was "I'd like to analyze logins by users in Excel", despite a dashboard approach would be sufficient. With a few million records aggregating in Excel wasn't particularly appealing

Download the log

Salesforce setup allows to download the log as csv or csv.gz file. In any case you should use the later. I learned the hard way: the chunked transfer encoding might leave you with less data be processed than you expect.

The Scanner simply stopped after a few thousand entries, while the csv parser barfed with an error.

Processing

After downloading and extracting the csv I used a small Java routine (yep, I'm that old) to aggregate logins per user, capturing the count and the first/last login date as well as the country of login (with the disclaimer caveats) and the eventual community.

For reliably and robustly reading csv in Java, usually I would use a robust library, however in this case having no dependencies and using the scanner did just nicely