Is there a better way to simply convert an array to a string?

Question

When I do a get from a given web service, I often have a single value being returned, but within an array.  What happens is I end up with this type of output [“Andrew”] rather than say “Andrew”
In order to write this value, always the 0 level value I end up hacking it with something like the path for the first values.
jsonPath($, “$Student**[0]**.Student_Data[0].Student_Person_Data[0].Personal_Profile_Data[0].Date_of_Birth”)
Here is a screenshot of the input schema for reference:

cjhoward18 · Answer

cjhoward18:

$.getFirst(‘Student’).getFirst(‘Student_Data’).getFirst(‘Student_Person_Data’).getFirst(‘Personal_Profile_Data’).Date_of_Birth

@acesario Sorry I forgot to format the expression so the quotes got bad formatting. Try this expression correctly formatted:
$.getFirst('Student').getFirst('Student_Data').getFirst('Student_Person_Data').getFirst('Personal_Profile_Data').Date_of_Birth

acesario · Answer

Just a comment on the impact to productivity… I have between 40 and 70 fields to map, multiplied by an average of 4 changes to the mapper to include the 0.   So any real time savings of no code, gets eaten up with this tedious manual task. I also worry about using [0] in this fashion, as I was taught that this is bad practice in xslt/xpath.

cjhoward18 · Answer

Hi @acesario
I think the getFirst() method could help your scenario.
I think the expression using getFirst() with your example would look something like this:
$.getFirst(‘Student’).getFirst(‘Student_Data’).getFirst(‘Student_Person_Data’).getFirst(‘Personal_Profile_Data’).Date_of_Birth
This relies on those fields always being present and arrays. If there are times that is not true additional logic will be needed.

acesario · Answer

cjhoward18:

$.getFirst(‘Student’).getFirst(‘Student_Data’).getFirst(‘Student_Person_Data’).getFirst(‘Personal_Profile_Data’).Date_of_Birth

Thank you for your response  @cjhoward18.
However, my snap seems to be requiring jsonpath…  if I do a getFirst (‘Student’) as prescribed I get a ‘could not compile expression’ error as shown:

This seems to happen sometimes when pulling from a web service, where the response is structured as array [*] object.  I had tried a get in places across my pipeline, and hit similar issues. Im unclear on the usage and why this occurs, but get/getfirst seem limited to certain objects.

acesario · Answer

That worked, thank you for the getfirst syntax and idea.  I dont mean to complain, just that this requires multiple steps per mapper row and more time and potential for human error.  I have to 1. Map the field. 2. Copy the field from snaplogic to text editor  3. review the path, and 4. make adjustments to include the get first. Copy/paste back into the field in snap. (I copy out of snap because the editor window is to tight to work with.)
This is actually more time than using [0].   Is there any advantage to using mapfirst rather than jsonpath [0]?

Forum Discussion

Is there a better way to simply convert an array to a string?

Recent Discussions

Javascript to promote top level lists

Google Sheets Subscribe questions

Basic string transformations not working

Can we generate XML file in pretty print format using native snapLogic snaps?

Multipart Reader failure - 'content-type' was not found