Unable to fetch the specific element value using jsonpath node js library

Question

I'm trying to fetch the value of element based on it's value in the complex JSON file.

Trying to fetch the value attribute (Which is 100) if the currency ='BRL' and the index will be subject to change so I just want to try with condition based.

I just tried below so far:

Script:

function test()
{
   var result = jsonpath.query(payload,"$..client_balance[?(@.type == 'AVAILABLE')]");
   console.log(result);
}

test();

Output:

[
  {
    amount: { currency: 'BRL', value: '100', skip: false },
    type: 'AVAILABLE'
  },
  {
    amount: { currency: 'USD', value: '10', skip: false },
    type: 'AVAILABLE'
  }
]

Now, I just wanna fetch the value attribute (Which is 100) if the currency code = 'BRL'. I tried to apply the [?(@.currency == 'BRL')] in the tail of the path variable but it returned empty array.

can someone help me to solve this problem.

Updated:

Tried filter function to get the specific element value.

console.log(Object.values(payload).filter(element =>{
    element.currency === 'BRL';
   }));

Output:

[]

Answer 1

This is a bit of a complex query, but it should get you what you're looking for.

Start with what you have, which returns the result set you posted:

$..client_balance[?(@.type == 'AVAILABLE')]

Add to this another filter which looks inside the amount field at the currency field for the comparison:

$..client_balance[?(@.type == 'AVAILABLE')][?(@.amount.currency === 'BRL')]

This should give just the one element:

[
  {
    amount: { currency: 'BRL', value: '100', skip: false },
    type: 'AVAILABLE'
  }
]

From here you want to get the value field, but to get there, you need the path to it, meaning you have to go through the amount and currency fields first.

$..client_balance[?(@.type == 'AVAILABLE')][?(@.amount.currency === 'BRL')].amount.currency.value

This should return

[
  100
]

---

Please note that we are working on a specification for JSON Path. If this library chooses to adhere to it once published, the === will need to change to a == as this is what we've decided to support.