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Tommy's avatar
Tommy
New Contributor III
4 years ago
Solved

Checking for existence of an array in a mapper

Hello. Im looking for a way of dealing with JSON documents that are sometimes recognised as an array, and sometime not. In the below example, i need to manipulate the “message” element to remove cert...
  • Aleksandar_A's avatar
    Aleksandar_A
    3 years ago

    Hello and welcome @Senthilnaga91,

    You can achieve the needed transformations by using two Mapper Snaps like in the picture below.

    In the first Mapper we’re mapping the Account Details array:

    And, in the second one we’re mapping the Customer Entry object:

    Also you can refer to the sample pipeline attached below.

    sl-comm-nested-json-api_2023_05_30.slp (5.5 KB)

    Let me know if this helps you.

    Regards,
    Aleksandar.

koryknick's avatar
koryknick
Employee
4 years ago

You might be able to get around it by using the following expression in a mapper before trying to process the $messages value:

sl.ensureArray($messages)

This way, if it is a single object, it will be a single-entry array. If it is already an arrary, it simply passes through.

ptaylor's avatar
ptaylor
Employee
4 years ago

Yes, Kory is correct: it’s standard practice to use sl.ensureArray() on such elements. This is particularly the case when dealing with documents that were converted from XML. Unlike JSON, XML doesn’t have an explicit syntax for arrays, so there’s ambiguity when converting an element with one child – it may or may not represent an array with one element.