How to identify matching values to create sequence numbers?

Looking for a function to help add sequence numbers to a json array. End goal is to apply a sequence to matching values, starting with 01, subsequent values get a sequence of 02…03… 04 etc. I could do this in a mapper, or in apache velocity as part of a soap execute if possible to loop through, and apply therein.

What I have now:
[
{
“Records”: [
{
“Award”: [
“Award_A”,
“Award_C”,
“Award_A”,
“Award_B”,
“Award_C”
]
}
]
}
]

Desired output:
[
{
“Records”: [
{
“Award”: [
“Award_A”,
“Award_C”,
“Award_A”,
“Award_B”,
“Award_C”
],
“Sequence”: [
“01”,
“01”,
“02”,
“01”,
“02”
]
}
]
}
]

Hi @acesario,

Hope this will solve your problem.

Expression:
$Records.map(record => record.Award.map((x, index) => record.Award.slice(0, index + 1).filter(y => y == x).length))

Output:
Output1

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@viktor_n Thanks for the response, great use of map approach! One thing I notice is that your resulting Sequence has a separate array for the sequence values [[1,1,2,1,2]] rather than
“Sequence”: [“01”,“01”,“02”,“01”,“02”]

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@acesario try this one.
$Records.map(record => {"Award": record.Award, "Sequence": record.Award.map((x, index) => record.Award.slice(0, index + 1).filter(y => y == x).length.toString())})

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@acesario , you can also just add [0] after @viktor_n’s expression.

$Records.map(record => record.Award.map((x, index) => record.Award.slice(0, index + 1).filter(y => y == x).length))[0]

And if you really need the “0” you can try and add .map(val => "0" + val)

So full expression is: $Records.map(record => record.Award.map((x, index) => record.Award.slice(0, index + 1).filter(y => y == x).length).map(val => "0" + val))[0]

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This is great, I need to learn the map method much better I see. I found an initial tutoral here JavaScript Array map() Method, any other learning recommendations?

This worked perfectly… not sure who to give the solution to… Viktor solved the basic approach problem, j dialed in. thanks to each of you!

My recommendation is to learn as much as you can of them, but I think most of the times are used Arrays, Strings, Objects, Dates.

The Expression Language is loosely based off of JavaScript expressions, so you could use JavaScript resources to try and learn some of them better. The official documentation for the language is here and we try to give some examples, although maybe they could be flushed out more. There is also a section of this community dedicated to learning it, but there isn’t a whole lot of content yet.

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Here’s another great resource related to learning the Expression Language, where @koryknick goes over his starter pack in a video tutorial.

@viktor_n , @j.angelevski
My initial testing worked with a limited record, however I’m noticing as I apply this to a more extended record structure, how the predicate of [0] impacts this. In this case, it always hits the first record, writing that result to each record. So if the first record has 2 awards, and the next has 5 it creates only two sequences on the second due to the [0]. Any ideas on how to define the predicate for the current record, rather than the first?

Just remove [0] at the end.

When I remove the [0] at the end it does produce all, but it changes the structure from to []. And as I was pushing this to jsonPath($, “$Records[*].Sequence”), it no longer keeps sequence inline with the record.

@acesario , I am not sure I understood what you mean by that ? Maybe you want something like this ? image

No, more like :

“Records”: [
{
“Award”: [“Award_A”,“Award_B”,“Award_C”,“Award_A,“Award_B”,“Award_C”],
“Sequence”: [“01”,“01”,“01”,“02”,“02”,“02”]

“Award”: [“Award_A”,“Award_C”,“Award_A”,“Award_B”,“Award_C”],
“Sequence”: [“01”,“01”,“02”,“01”,“02”]

“Award”: [“Award_Z”,“Award_C”,“Award_A”],
“Sequence”: [“01”,“01”,“02”]

“Award”: [“Award_B”,“Award_C”,“Award_B”],
“Sequence”: [“01”,“01”,“02”]

“Award”: [“Award_A”,“Award_B”,],
“Sequence”: [“01”,“01”]

If I understand correctly, this is the right output format?

If that so, you can try the following expression:

$Records.map(record => {“Award”: record.Award, “Sequence”: record.Award.map((x, index) => (record.Award.slice(0, index + 1).filter(y => y == x).length.toString()).length == 1 ? (“0” + record.Award.slice(0, index + 1).filter(y => y == x).length.toString()) : (record.Award.slice(0, index + 1).filter(y => y == x).length.toString()))})

It’s a bit complex, but only because of it’s functionality to check the sequence number. If it’s one digit number, it will add “0” in front of it, if not, it will show the actual number.

I surely hope that this will help,
BR,
Bojan

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