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matt_bostrom's avatar
matt_bostrom
New Contributor II
8 years ago

Removing a column from JSON array

Hello. say i have the following JSON:

how can i remove one of the attributes / columns? Let’s say in the top left from the image above I want to remove the OwnerEmail value from that array… how could i do that in snaplogic? i’ve tried remapping but that breaks the grouping.

9 Replies

  • Hi @acesario,

    There is an expression. You can remove all field that are null or only by specific fields.
    For this you must use Mapper and you need to have checked Pass Through checkbox and also target path need to be empty.

    $group...[?(value == null && key == "fieldName")]

    $group: Is an array and if you remove the “group” and let stay only “$” then it will work again but it will check through whole document.

    value: We specify what value we want to remove. In this situation is null.

    key: If we have to specify name of field that we want to remove, then we set key in the conditions. If we only need to check by value then remove the key. Ex: $group...[?(value == null)]

    Regards,
    Viktor Nedanovski

  • hi @robin. the catch is (that i probably should have mentioned) is i am grouping the rows by the OwnerEmail b/c further down the pipeline I email the user 1 single email with an HTML Table email snap. The table loops through the $group variable. While the Group By Fields I set the OwnerName like so… the subgrouping $groupBy still contains the field that I grouped by that I don’t want in the html table in the email.

    here is what my json looks like (i blurred out the real emails but you can see the structure and the group part where i want to remove the owneremail value):

    • tstack's avatar
      tstack
      Former Employee

      The thing to delete in the Mapper is interpreted as a JSON-Path. In Robin’s example, it’s just a top-level property in the document. But, you should be able to use a path like the following to walk an array and delete the property in all the objects in the array:

      $group[*].OwnerEmail
      

      So, this path will walk through all the elements in the ‘group’ array (the $group[*] part) and delete the ‘OwnerEmail’ properties.

  • this isnt working for me!!
    Could not compile expression: $group[].matchfield (Reason: Encountered extraneous input ‘[’ at line 1:6; expecting={, ‘||’, ‘&&’, ‘^’, ‘==’, ‘!=’, ‘>’, ‘<’, ‘>=’, ‘<=’, ‘+’, ‘-’, '', ‘/’, ‘%’, ‘?’, ‘instanceof’, ‘in’, ‘.’}; Resolution: Please check expression syntax)

    • tstack's avatar
      tstack
      Former Employee

      Make sure the “Target Path” column in the mapper is cleared. Otherwise, the mapper will treat the first column as an expression, which is what it looks like is happening here. (When the Target Path is clear, the first column is treated as a JSON-Path that specifies what should be deleted in the input document).

      • acesario's avatar
        acesario
        Contributor II

        How would you do this conditionally? Meaning, if the incoming value is NULL, remove the property?