Jolt transformation to insert a value into existing array object

Question

I have an array object amount and a variable amountVar. I need to insert the value in amountVar into amount array at 2nd position.

Here is the input JSON Input

{
"PTL" : {
    "TA" : [ {
      "T" : [ {
        "amount" : [ 10, 11, 21 ],
        "amountVar" : 7
      } ]
    }, {
      "T" : [ {
        "amount" : [ 20, 22, 22 ],
        "amountVar" : 6
      } ]
    }, {
      "T" : [ {
        "amount" : [ 30, 33, 23 ],
        "amountVar" : 16
      } ]
    } ]
  }
}

Tried using modify-overwrite-beta operation to rewrite the array by specifying the elements to insert { "operation": "modify-overwrite-beta", "spec": { "PTL": { "TA": { "": { "T": { "": { "amount": [ "@(1,amount[0])", "@(1,amountVar)", "@(1,amount[1])", "@(1,amount[2])" ] } } } } } } }

Expected output

{
"PTL" : {
    "TA" : [ {
      "T" : [ {
        "amount" : [ 10, 7, 11, 21 ]
      } ]
    }, {
      "T" : [ {
        "amount" : [ 20, 6, 22, 25 ]
      } ]
    }, {
      "T" : [ {
        "amount" : [ 30, 16, 33, 23 ]
      } ]
    } ]
  }
}

Here is the input JSON Input

{
"PTL" : {
    "TA" : [ {
      "T" : [ {
        "amount" : [ 10, 11, 21 ],
        "amountVar" : 7
      } ]
    }, {
      "T" : [ {
        "amount" : [ 20, 22, 22 ],
        "amountVar" : 6
      } ]
    }, {
      "T" : [ {
        "amount" : [ 30, 33, 23 ],
        "amountVar" : 16
      } ]
    } ]
  }
}

Tried using modify-overwrite-beta operation to rewrite the array by specifying the elements to insert { "operation": "modify-overwrite-beta", "spec": { "PTL": { "TA": { "": { "T": { "": { "amount": [ "@(1,amount[0])", "@(1,amountVar)", "@(1,amount[1])", "@(1,amount[2])" ] } } } } } } }

Expected output

{
"PTL" : {
    "TA" : [ {
      "T" : [ {
        "amount" : [ 10, 7, 11, 21 ]
      } ]
    }, {
      "T" : [ {
        "amount" : [ 20, 6, 22, 25 ]
      } ]
    }, {
      "T" : [ {
        "amount" : [ 30, 16, 33, 23 ]
      } ]
    } ]
  }
}

Answer 1

one way to solve this problem is to use the =toList() function.
First you have to split the already existing list and converting it into a dictionary:
so for example the first "amount" would look like this:

 "amount" : {
   "0" : 10,
   "1" : 11,
   "2" : 21
 }

And then putting the corresponding "amountvar" in the same amount.

After that you can use the =toList() function to create a list with the wanted elements in any order you desire.

Finally you extract the list you created and remove the other variables.

Here is the spec:

[
  {
    "operation": "shift",
    "spec": {
      "PTL": {
        "TA": {
          "*": {
            "T": {
              "*": {
                "amount": {
                  "*": {
                    "@0": "&7.&6[&5].&4[&3].&2.&0"
                  },
                  "@(1,amountVar)": "&6.&5[&4].&3[&2].&1.var"
                }
              }
            }
          }
        }
      }
    }
  },
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "PTL": {
        "TA": {
          "*": {
            "T": {
              "*": {
                "amount": {
                  "list": "=toList(@(1,0),@(1,var),@(1,1),@(1,2))"
                }
              }
            }
          }
        }
      }
    }
  },
  {
    "operation": "shift",
    "spec": {
      "PTL": {
        "TA": {
          "*": {
            "T": {
              "*": {
                "amount": {
                  "@(0,list)": "&6.&5[&4].&3[&2].&1"
                }
              }
            }
          }
        }
      }
    }
  }
]

This only works for lists with 3 elements in it, if there were more, you had to manually change the toList function, adding every element in the order you prefer