Pass information back from called form
- Thread starter pdanes
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What does scaling mean in your sentence? Does it mean that the function/class will be used by different forms/reports in the future or that the function/class can be modified to do additional things? Nothing I suggested violates the first definition. But the second definition is the road to unintended consequences. The calculation performed by the class/function uses fldA and fldB. I don't use sloppy names in my application so I don't have to worry about not being able to use the class/function with a different form/report because the necessary variables will have consistent names. So my function is infinitely scalable as long as I don't expect it to work on fldC and fldD.
Simplicity reduces the potential for bugs. The code being called has a specifically defined purpose. If you change its purpose, you should probably build a new class/function rather than having to go back and find every piece of code that references the class/function to determine if the change to the calculation will cause a bug in some cases because one of the values is not available or return invalid results because originally, the function was returning the subtotal before tax and now you want to change it to return the total including the tax. Think about all the times you have updated Access and some bizarre feature breaks like your reports all revert to currier as their font? I seem to remember something stupid that a few years ago. Why did that happen? It is important to avoid a ripple effect. It is better to make a new class that takes the additional variable and finishes the calculation after executing the original class/function.
If a class is used only by forms/reports you can have each form/report pass 3 variables or however many the function/class required or you can pass the function/class the object (form or report) and let the function/class get its own data. If it turns out later (remember scalability) that the function/class now needs a 4th variable, think about the changes (ripple effect) that are required if I am specifically passing variables vs what needs to change if the class/function can get the 4th variable by itself. I change potentially dozens of forms to alter the calling parameters or I just change the class/function.
A class/function simply cannot be all things to all people. It does what it does and scalability does not affect it. It is only when you try to reuse objects in unintended ways that you run into problems with scalability.
