Should Automatically Evaluate be on by Default?


I've changed my settings in the Data Viewer to OFF recently - and I'm wondering why I didn't do this years ago.

What does your checkbox for "Automatically Evaluate" look like in the Data Viewer?

  • Always On
  • Always Off
0 voters

Once in development of a new version of FileMaker, they did auto evaluate as default. We argued with Claris that we need to not have auto evaluate since plugin calls in the calculation can have side effects. So I want to type the whole calculation and press the button when I am finished.

Simply imaging calling a Delete function and typing the path to just delete whole folders instead of one file.


Often, the values stored in the data viewer created a new set of "false problems" when I was testing. I learnt that it was only safe to store read-only functions but I had not turned off the "automatically evaluate" switch.

Some months ago, I switched evaluation off because I was doing a particularly taxing calculation. I took me a while to realise how much safer it was to have the switch off. Now it is off permanently.


I have to admit, it was ON for me. That's why I voted the way I did. But now I've changed it: The switch is now set to OFF.

Thanks for bringing this up @Malcolm

Normally "ON" makes more sense for me, since I don't have to click every single time I want to see a result. That would be too annoying for me. But I switch it OFF, when I test a SQL function, because it can massively slow down the input.

Voted OFF.

I usually code calculations in data viewer (watch) and for example if some loops (while, cfs) have bugs like endless loops they can crash fmp or at least stall it. So it is safer to have it off. Sometimes i turn it on temporarily.


Thank you guys for this discussion. Automatically Evaluate can be a pain when you debug a calculation that fails. Turning it off brings more advantages than inconveniences.

Automatically Evaluate gets me when I'm freehanding a Let calc that sets $$ variables.

When writing this:

Let ([
	$$hello = "world"

I end up with a data viewer like this:

$$ = "world"
$$h = "world"
$$he = "world"
$$hel = "world"
$$hell = "world"
$$hello = "world"

What is this ?

The data viewer evaluates on every keystroke so every letter I type in the variable name(hello) gets set to the value "world" (assuming the rest of the expression is valid fm syntax of course)

Just another gotcha with auto-evaluate

Was on, now off.

World's slowest Typist
:trophy: :snail: :keyboard:

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:rofl: hey cut me some slack, I just switched to a mechanical keyboard and totally suck at typing lately!

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I need a vote for "it depends"… I often leave it on for convenience. But there are definitely times when I turn it off. Particularly when testing "expensive" SQL calcs and the like.

But then I leave it off and the next time I go to use is I wonder why my simple calc isn't working! :rofl:

using an app like Keyboard Maestro can assign a hotkey to the evaluate button

Always on, I never write inefficient calculations :slight_smile: