Uniface 10.4: What's the Deal with the 'any' Data Type? 🤔

Hey everyone! 👋 If you're working with Rocket Uniface, you know it has its own unique way of doing things. Today, let's dive into one of its most flexible features: the any data type.

A quick note: This article was drafted with the help of an AI assistant 🤖 to break down the official documentation into a simple guide.

What is 'any'?

Think of the any data type as a chameleon. It's a special kind of variable or parameter that doesn't have a fixed data type. Instead, it can hold any kind of data you throw at it. When you assign a value to an any variable, it temporarily becomes the data type of that value.

This is similar to how dynamic works in C# or any in TypeScript. It's a placeholder for data when you don't know (or care) what the specific type will be at compile time.

Where Can You Use It?

According to the Uniface 10.4 documentation, you'll most often use any in two places:

• In the params block of an operation (a function or method). This allows you to create flexible operations that can accept different types of input.
• In the variables block of a component to define a component variable.

💡 To define a global variable of this type, you simply choose $ from the Data Type list in the Uniface editor.

Let's See an Example ✍️

Here’s a simple ProcScript example to show how any behaves. Imagine this code is inside a component's operation.

variables
  any vMyFlexibleVar
endvariables

; At this point, vMyFlexibleVar has no specific type.

vMyFlexibleVar = "Hello, Uniface!"
; Now, vMyFlexibleVar behaves like a string.
message "The value is '%%vMyFlexibleVar%'"

vMyFlexibleVar = 12345
; Now, it behaves like a numeric data type.
vMyFlexibleVar = vMyFlexibleVar + 5
message "The new value is '%%vMyFlexibleVar%'"

vMyFlexibleVar = "D2025-11-02"
; Now, it behaves like a date.
message "The date is '%%vMyFlexibleVar%'"

As you can see, the same variable vMyFlexibleVar seamlessly holds a string, a number, and a date without any errors.

Typical Problems and Words of Caution ⚠️

While any is very powerful, it comes with a trade-off: you lose type safety.

The biggest problem is potential runtime errors. Since the compiler doesn't check the type, you could easily try to perform an operation that isn't valid for the data currently in the variable. For example:

variables
    any vMyVar
endvariables

vMyVar = "This is a string"
vMyVar = vMyVar + 10 ; This will cause a runtime error!

Because Uniface can't add a number to a string in this way, your application would stop with an error. When using any, it's your responsibility as the developer to make sure the data is of the correct type before you use it, perhaps by using functions like $datainfo to inspect the type first.

Conclusion

The any data type is a great tool for building flexible and generic components in Uniface. However, use it wisely! It's perfect for situations where you truly need to handle multiple data types, but relying on it too much can make your code harder to debug.

Happy coding! 🚀