Is there a way to do this? Am using conditions to handle which numbers ARE allowed and to display an error if invalid numbers are entered. But can't get it to stop letters etc from being entered/processed. Hopefully I'm having a Friday moment and missing something simple

I gave this problem some more thought today, and did finally find a way to workaround this within SL (it seems), but the solution is somewhat complex. I've attached the story file for anyone interested in seeing/trying the implementation. The result is that I can detect a NaN entry (the basic problem we were discussing above), then overwrite the "NaN" display in the field with a more meaningful/desired default value (in this case, that's the number 0), and pop-up a feedback message indicating "invalid entry" as a way of getting good usability for this type of entry field. The core breakthrough here (at least for me) was realizing that the NaN condition could be detected by evaluating the entry value against the condition of all possible numbers (the conditions being IF less than or equal to 0, OR greater than 0 --- in other words, all numbers --- this seems kind of obvious in retrospect). This is detected and acted on with a set of sequential triggers and intermediate variables as shown below. (since the conditional choices in the trigger wizard do not support "Not" conditions for the comparative operators, the logic ends up needing to be a lot more complex than it would have been otherwise, because I can only detect and qualify a trigger based on the entry being a number, rather than on not being a number). The logic is based on a boolean "isNaN" flag variable that gets initialized to true, and is then reset to false if the entry is a number using the conditions mentioned above --- this will evaluate each time an entry is made. The sequence (order) of some of the triggers that are driven by a change in the "copyOfEntry" variable is crucial -- this is a good example of how multiple triggers (based on the same event) need to be laid out in a precise order, and how that order of execution can be used to your advantage. The intermediate "copyofEntry" variable was needed as a proxy variable for the raw input value, otherwise the action of resetting the raw variable to zero (when NaN occurs) causes a sort of recursive event loop problem (if only one value variable is used). The feedback message is implemented on a layer. The two added "numeric entry" object triggers are needed (one for loss of focus, and one for the enter key) so that either clicking outside the field or hitting enter will cause the value to be processed as a new input. If anyone can see an easier path to achieving this, I'd love to see this simplified, but this does seem to do the trick for me at least. While this works, it does seem like logic overkill for simply dealing with the NaN issue.. It would be much better if the NaN condition could be added to the SL condition options dropdown for numeric variables to make such handling a piece of cake..... and it would be nice if "Not" operators were allowed to be optionally added in front of the conditional operators (that would have cut the complexity here in half). A feature request has been submitted for such NaN condition checking. - Doug

Another possible way to avoid nan is by using an execute JavaScript trigger after the setting the variable value: This is the JavaScript code to run:

Hey Simon, I had the same problem and I tried to leave with a 0, this way, in a group it can calculate the sum of the fields.I see that this conversation is from 5 years ago, so I hope you had solved XD, but if can be useful for other people I did this:IF( NOT( {string} > 0) , 0 , {string})

Maybe switching to text entry gives more control over "incorrect" entries? Will try later.

But if that was the case, then surely you'd have this issue when having to us numerical entry, e.g. for calcs etc. If you still want to collect numbers but don't need to calc them then I guess you're okay.

Can I prevent "NaN" from appearing in numerical entry?

Amanda-Gunning
Community Member
7 years ago
Hi there

I would like to add up a couple of numbers in Storyline 3. I thought I could use the number entry field to do this? The number goes in fine but when I try to add the value that was entered to a variable to add up a score, I get the NaN issue.

Is there a simple way around this yet? I am really suprised Storyline can't add a number(s) to a variable. Maybe I am missing something here?

I have tried the following workarounds:

1. setting the value of the total variable to 0 when the timeline starts.
2. changing the state of a tick/check image if the correct number is entered to normal.
3. using a drop down question but I have several of the same numbers including 0 to select.

None of these work. I don't quite get how to apply the javascript so haven't tried that. Any explanation on how to add that would be helpful. e.g. do you just add the script and replace inH1 = numericentry1 variable?

Many thanks for any help with this.

Amanda
Doc1.docx265 KB
- MichaelHinze
  Community Member
  7 years ago
  It would be easier to help, if you can share your .story file (or the one slide) here.
  - Amanda-Gunning
    Community Member
    7 years ago
    Hi Michael
    
    Please see attached.
    
    Many thanks
    
    Amanda
    adding_up_issue.story3.7 MB
SarahLyon-b2d06
Community Member
4 years ago
I have successfully built out a calculation slide that works well when previewed. I have duplicated the slide in the same scene with the hopes of changing the scenario users will work through. Before making any changes to the duplicate slide I tested it and it's getting the the "NaN" error. Why would something work fine then when I duplicate it no longer work? I have read through the responses above and have not been able to fix the issue.
KenFlieger
Community Member
4 years ago
NAN is 'Not A Number' error in JavaScript. If you are not using custom JavaScript code then it bares down to extremely bad coding on the developer's side. The developer has to trap any strings, Infinity numbers and spaces or any other value the user may enter that is not a number value. Sloppy code writing.
SarahLyon-b2d06
Community Member
4 years ago
I didn't use any Javascript (I'm new to Storyline) and simply used the the programing within Storyline to assign variables and so on. I used this tutorial to build it. https://community.articulate.com/articles/setting-variables-to-perform-a-calculation-in-articulate-storyline
- BeccaLevan
  Community Member
  4 years ago
  Hi Sarah!
  
  Any chance you could share your file? If folx can see what you have going in your project, it'll be easier to pinpoint what's going on and make suggestions!
KevinMcGrath
Community Member
2 years ago
Found this old thread when trying to solve the same issue in JavaScript. Thought I'd post here in case anyone else needs this solution:

a = a || 0

adding || 0 tell JS that if there's errors on the left side (e.g. NaN) then return a value of 0.
LucianaPiazza
Staff
2 years ago
Thanks for sharing the solution that worked for you in this thread, Kevin! I'm sure it will be helpful to other community members that come across this post.

Have a great day, and happy developing! ✨