Question about Context Variables and Clearing an Object Data Type

[tommyly]

This is one of those weird questions where it may have already been discussed, but hidden behind unexpected subject terms. If this is the case, can you please supply a link? Thanks.

So I've been playing around with the idea of assigning objects to context variables (as well as collection fields). For example:

UpdateContext(myContextVariable, First(Filter(myCustomerSPList, ID=100)))

Once I've assigned myContextVariable to this item, I can refer to my customer as myContextVariable.FirstName. This is my intention. Now, I run some subsequent filters based on this data, so at some point, I'd like to clear out this data.

If I type in Clear(myContextVariable), I get an error because it's not a "collection" data type. If I type UpdateContext(myContextVariable, ""), I also get an error because it's not a "text"  data type. It's an "object" data type. How do you clear that? Thanks.

https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-updatecontext

[Anonymous]

Hi tommyly

Interesting that your function below worked as well. 

UpdateContext(myContextVariable, First(Filter(myCustomerSPList, ID=100)))

I usually work with the following syntax as indicated in the documentation site you referred to: 

UpdateContext( { ContextVariable: Value})

This would suggest that updating your context variable may be possible using:

UpdateContext ( { myContextVariable: "" } )

[Scobie · Accepted solution]

Hi @tommyly, 

This was interesting as I hadn't thought much about a context variable being a object or record type. 

To Clear this value for the vaiable you can make use of the Blank() function . As shown here:

https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-isblank-isempty

using the syntax:

UpdateContext({myContextVariable: Blank()})

Scobie

[tommyly]

That seems to do the job. Thanks!

[salvadorplj]

The safest way to clear a variable is by being explit about the data type you hold in it, that way you wont have any issues if processes' steps intermix.

Instead of:

UpdateContext({SunShine: Blank()});

Do: 

UpdateContext({SunShine: DateTimeValue(Blank())});