Remove all the values from JSON object with null value Using jsonpath - json

Question

I have a JSON file from which I need to remove node objects which contain a data value of null. Can this be done?
In the sample JSON below, I need to remove the object where all the tag has a null value.
{
"store" : {
"book" : [
{
"category" : "reference",
"author" : "Nigel Rees",
"title" : "Sayings of the Century",
"price" : 8.95
},
{
"category" : "fiction",
"author" : "Evelyn Waugh",
"title" : "Sword of Honour",
"price" : 12.99
},
{
"category" : "fiction",
"author" : null,
"title" : "Moby Dick",
"isbn" : "0-553-21311-3",
"price" : 8.99
},
{
"category" : "fiction",
"author" : null,
"title" : "The Lord of the Rings",
"isbn" : "0-395-19395-8",
"price" : 22.99
}
],
"bicycle" : {
"color" : null,
"price" : null
}
},
"expensive" : 10
}
We tried using JOLT :
[
// Flatten an array of photo objects into a prefixed
// soup of properties.
{
"operation": "modify-overwrite-beta",
"spec": {
"*": "=recursivelySquashNulls"
}
}
]
But this is resulting in removing Null values but also it is not removing empty json fields
Output which we are getting
{
"store": {
"book": [
{
"category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
},
{
"category": "fiction",
"author": "Evelyn Waugh",
"title": "Sword of Honour",
"price": 12.99
},
{
"category": "fiction",
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"price": 8.99
},
{
"category": "fiction",
"title": "The Lord of the Rings",
"isbn": "0-395-19395-8",
"price": 22.99
}
],
"bicycle": {}
},
"expensive": 10
}
and expected Output is
{
"store": {
"book": [
{
"category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
},
{
"category": "fiction",
"author": "Evelyn Waugh",
"title": "Sword of Honour",
"price": 12.99
},
{
"category": "fiction",
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"price": 8.99
},
{
"category": "fiction",
"title": "The Lord of the Rings",
"isbn": "0-395-19395-8",
"price": 22.99
}
]
},
"expensive": 10
}
Any Suggestions How we can do this ?

Answer 1

You rather can use the following spec instead of using recursivelySquashNulls by interchanging key-value pairs through use of "$": "...#(0)" pattern
[
{
// convert price values to strings in order to keep the decimal part of them during the interchange operation
"operation": "modify-overwrite-beta",
"spec": {
"store": {
"book": {
"*": {
"price": "=toString"
}
},
"*": {
"price": "=toString"
}
}
}
},
{
// interchange key-value pairs to get rid of the both values null and null object -> { }
"operation": "shift",
"spec": {
"store": {
"book": {
"*": {
"*": {
"$": "&4.&3.&2.#(0)"
}
}
},
"*": {
"*": {
"$": "&3.&2.#(0)"
}
}
},
"*": {
"$": "#(0)"
}
}
},
{
// switch to the original
"operation": "shift",
"spec": {
"store": {
"book": {
"*": {
"*": {
"$": "&4.&3[&2].#(0)"
}
}
},
"*": {
"*": {
"$": "&3.&2.#(0)"
}
}
},
"*": {
"$": "#(0)"
}
}
},
{
// preserve the decimal value as they are
"operation": "modify-overwrite-beta",
"spec": {
"store": {
"book": {
"*": {
"price": "=toDouble"
}
},
"*": {
"price": "=toDouble"
}
}
}
}
]
the demo on the site http://jolt-demo.appspot.com/ is