Tips & Tricks for your 4D Apps – October 2024 Edition

by Add Komoncharoensiri, Director of Technical Services at 4D Inc

Here we go with another set of tips and tricks.

The 4D Knowledge Base is a library of information about 4D technology where weekly tech tips and monthly tech notes are actively published. If you missed the last tips on the KB, that’s fine; here is a compilation from the past few weeks.

This blog post covers 25 tips:

1. 1. 1. Session Command Returns Null
      2. 4D Appearance Settings
      3. How to refresh record when data is updated in another process
      4. Better usage of user licenses with REST requests by enabling Force Login Mode
      5. Changing remote client user after checking off “Remember password”
      6. Checking for Cache Thrashing on a 4D Server Using the 4D Info Report Component
      7. Getting the last table number
      8. 3 different ways to create a new method or class in Design environment
      9. Security and Convenience with Auto-Generated SSL/TLS Certificates
      10. Changing the fill color of alternate listbox rows with CSS
      11. New log file Numbers Explained
      12. How to Implement an HTTP Agent as a Singleton
      13. Using Pointers to Tables in Object Literals 
      14. OrderByMethod not sorting correctly 
      15. Store singleton class instance in a variable for convenience in typing 
      16. How to Fix Orphan Licenses
      17. Compiling a 4D Database
      18. Checking if a property does not exist in an object (null vs. undefined) 
      19. “Failed to Synch Resources” when connection to 4D Server 
      20.  Inherent Truthy and Falsy Values with Short Circuit Operators 
      21. REST Error Message: “Can’t call not thread safe method from a preemptive process” 
      22. Get and SET DATABASE PARAMETER Thread-Safe Parameters 
      23. Better Readability with Collection and Object Literals 
      24. Avoid calling GOTO OBJECT directly inside On Data Change event of listbox column of checkbox display type 
      25. Changing TLS versions programmatically