Assigning a Function to a Variable and then calling it

Ignition
1

What is the correct way to call a function that has been assigned to a variable? I want to call a specific function depending on a parameter like this:

Decide Function Based on Column Name

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image1058Ă—1621 128 KB

Assigned to the variable it looks like this

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image908Ă—126 61.8 KB

I attempt to use it like this

count, ds = self.custom.searchFunction(combinedDs, returnDs=True)

This Error Happens

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image1147Ă—226 35 KB

Thanks,

Nick

2

When you assigned it to a Perspective property, it was stringified. Perspective properties cannot hold arbitrary jython objects.

3

ok, if that is something that I cannot change, I’ll just choose which function to call at the time of execution instead of trying to stick it in a variable.

There is no way to overcome this “stringification” correct?

4

You’re basically already making a map/dictionary. I assume you use this on some button press or something but in your onAction extension function (or wheverever, doesn’t really matter) you can do something like

funcs = {
"recircCount": common.flexsort.getRecircCount,
"overflowCount": common.flexsort.getOverflowCount,
"redLightCount": common.flexsort.getRedLightCount,
...
}

# some logic to figure out what key to use
keyToUse = ?

try:
    funcs[keysToUse]()
except KeyError:
    # Opportunity to use a fallback function if keyToUse is not in dictionary
    someDefaultFunc()

If you need to call this function mapping function in multiple places, you could also put it in a project script like

def callMappedFunction(keyToUse, *args, **kwargs):
    funcs = {
    "recircCount": common.flexsort.getRecircCount,
    "overflowCount": common.flexsort.getOverflowCount,
    "redLightCount": common.flexsort.getRedLightCount,
    ...
    }
    try:
        return funcs[keyToUse](*args, **kwargs)
    except KeyError:
        return defaultFunction(*args, **kwargs)

and call this where you need it on your view.

There is a way to go from the string name of your library to importing/calling the function using importlib I believe, but would probably recommend against it and just hardcode/white list what functions you want to allow.

5

Brian’s approach is good, but funcs needs to be at the top level of a project script to be most efficient.

2 Likes
6

I will try this and update the results here later on

1 Like
7

Not at the moment, no. There may be hope for the future, though. (: