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Uniface 10.4 Deep Dive: Understanding the $totocc Function 🚀

(Note: This blog post was drafted with the assistance of an AI to help structure and simplify the official technical documentation.)

Hello, fellow developers! 👋 Today, we're diving into a specific but powerful function in the Uniface 10.4 ProcScript language: $totocc. If you've ever worked with data occurrences in Uniface components, you know how important it is to keep track of what's in memory versus what's in the database. That's exactly where $totocc comes in handy.

Let's break it down in simple terms.

What is $totocc? 🤔

In short, $totocc returns the total number of occurrences (think of them as records or rows) of an entity that are currently loaded inside a component. This includes records you've retrieved from the database AND new records you've added but haven't saved yet.

The basic syntax is:

$totocc {(Entity)}
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The Entity parameter is optional. If you leave it out, Uniface assumes you mean the current entity you're working with.

The Key Difference: $totocc vs. $totdbocc 💡

This is the most important concept to grasp. These two functions might sound similar, but they track different things.

  • $totocc: Counts all occurrences currently in the component's memory.
  • $totdbocc: Counts only the occurrences that exist in the database for the current component instance.

Imagine you have a form showing customer data. You retrieve 10 customers from the database and then add 2 new ones on the form.

  • $totdbocc will be 10.
  • $totocc will be 12 (the 10 from the database + 2 new ones).

This difference is crucial for building logic that handles unsaved changes!

Let's See an Example! 📝

The best way to understand is with code. Let's say you want to show a message telling the user how many new records they've added before saving.

You could write a simple script in a trigger like this:


trigger detail
  ; Check if there are more occurrences in the component than in the database
  if ($totocc > $totdbocc)
    ; Calculate the difference (which is the number of new records)
    $1 = ($totocc - $totdbocc)
    message "You have added %%%$1 new customer(s)%%%."
  endif
end; detail
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In this example, if $totocc is 12 and $totdbocc is 10, the message will be: "You have added 2 new customer(s)." Simple and effective!

What Actions Affect the Value of $totocc?

Several standard ProcScript commands will change the value of $totocc during runtime. Here’s a quick summary:

  • ➕ Increases $totocc:
    • ^ADD_OCC: Adds 1.
    • ^INS_OCC: Adds 1.
    • read: Adds 1 for each record read.
  • ➖ Decreases $totocc:
    • ^REM_OCC: Subtracts 1.
    • discard: Reduces the count by the number of discarded occurrences.
  • 🔄 Resets $totocc:
    • clear: Resets the count to 1 (for the single empty occurrence).

Conclusion

And that's it! The $totocc function is a fundamental tool for managing data state within your Uniface applications. By comparing it with $totdbocc, you can easily determine what data is new, what's been retrieved, and build powerful, user-friendly logic around it.

Happy coding! 💻

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