Arcade expression to increase number value by 1 for every new feature

James_Shreeve

Hi, 

I have a dataset which is our primary use case for editing and when capturing new features I'm setting up smart forms to help the user. The main one I'm struggling with is our reference number and the ability to auto populate the next sequential number. The data field, just to confuse matters more, is a string. I'm getting better at arcade but still in my learning days so I think what I need to do is...

Our standard reference number format is "ESCO - 1234" and I'm just looking to increase the highest value by 1 each time a new record is created. The reference number is stored in the field "ESCO_Ref".

1) convert the string to an integer. The reference number will always be the last 4 characters of the string. 

 

var ESCO_num = Number(Right('$feature.ESCO_Ref', -7));

 

2) find the highest number and then add one to the value (taken from Go Beyond the Smart Editor using Smart Forms (esri.com))

 

// Define the edit context so the value is only calculated when the feature is created

if ($editContext.editType == "INSERT") {

  // Lookup the value for the last created feature

  var last_feature = First(OrderBy($layer, 'ESCO_Ref DESC'));

  // If the last value was empty write 1, otherwise add 1 to the value

  return IIf(IsEmpty(last_feature), 1, last_feature.ESCO_Ref + 1)

} else {r(Right('$feature.ESCO_Ref', -7));
  // When the feature is updated, return the existing value in this field

  // and do not calculate a new value

  $feature.ESCO_Ref

}

 

3) prefix the new value with "ESCO - "

 

return "ESCO - " + variable above

 

Whilst the above may be very clunky and possibly not correct, I'm just struggling with how to put the steps into one seamless expression. Any help would be greatly received folks! 

Many thanks!

James_Shreeve

Hi, thanks for getting back to me. It's been helpful, I kept trying to make the number array work but I could never seem to retrieve the number but I did hash together the below from using your code and the code in my original post which has worked a treat. 

// Define the edit context so the value is only calculated when the feature is created
if ($editContext.editType == "INSERT") {
  // Lookup the value for the last created feature
  var last_feature = First(OrderBy($layer, 'ESCO_Ref DESC'))
  // Extract the ESCO_Ref field
  var lf_esco = last_feature.ESCO_Ref
  // Convert to Number and remove prefix text
  var lf_esco_num = Number(lf_esco, 'ESCO - ####')
  // Add 1 to the number
  var lf_esco_new_num = lf_esco_num + 1
  // Convert back to text
  var lf_esco_text = Text(lf_esco_new_num)
  // Concatenate together with the prefix
  var new_esco_ref = Concatenate('ESCO - ', lf_esco_text)
  return new_esco_ref
} else {
  // When the feature is updated, return the existing value in this field
  // and do not calculate a new value
  $feature.ESCO_Ref
}