Hey Nate,
Sorry for the late reply. I am glad you were able to figure out your problem.
I implemented this solution directly to an indicator using the "advanced formatting" option. Deciding where to implement expressions to dashboards always depends on what function(s) you are trying to use and how you are trying to abstract your data. I was lucky and did not have to use any fancy expressions because indicators have advanced formatting built in. If your chosen data element does not have advanced formatting, you will have to program the data element from scratch using an expression written in Arcade.
It is important to note that "Arcade" is literally just javascript with an expanded library of functions. If one knows javascript, one basically already knows Arcade, it's just a matter of understanding and implementing the functions offered by the expanded library.
To hopefully help any users who may need assistance implementing DefaultValue, the exact code I used was this:
DefaultValue($datapoint["CUST_COUNT"], 'No Data')
As stated before, my indicator needed to display weekly customer counts. The data is uploaded by individuals/individual groups and thus there is noticeable margin of error at times. In the case of CUST_COUNT, this error would arise as a blank or "null" string entry in the .csv when there should be a zero integer.
DefaultValue works by checking a field of your choosing for null and blank entries and then returns a text string of your choosing upon encountering such an entry. It leaves "0" (zero integer) entries as is. All you need to do to implement the function is to insert the name of your field into square brackets with quotation marks as I did. After the comma, type what you want your dashboard element to display upon encountering a blank entry in quotation marks. It does not matter if you use single or double quotations for either/both inputs.
Hope this helps. Thanks Nate for your input!
-James