JSON object Ignore null

Question

Im kinda new to MuleSoft and DataWeave and im trying to make a JSON Object with only not null values from another JSON object.

Let's say this is my JSON array :

{
    str1 : "String 1",
    str2 : "String 2",
    str3 : null,
    str4 : "String 4",
}

I want to make a copy of that JSON array but without str3, so result should looks like this :

{
    str1 : "String 1",
    str2 : "String 2",
    str4 : "String 4",
}

Anyone can help me out with this ? or atleast lead me to the solutions ?

Regards

That is not a JSON array, it is a JSON object. And the keys are missing quotes. — aled, Jul 30 '20 at 15:20

score 4 · Answer 1 · answered Jul 30 '20 at 15:20

There are 2 possible approaches:

Using the writer property skipNullOn as mentioned here

output application/json skipNullOn="everywhere"
---
payload

Programatically with an if condition (this is for field by field mapping)

var b = null
---
{
    a: 1,
    (b: b) if b != null,
    c: 3
}

score 3 · Answer 2 · answered Jul 30 '20 at 15:24

3

For an object you can transform all the attributes that are not null:

%dw 2.0
output application/json
---
payload mapObject (($$): $ ) if (!($ == null))

answered Jul 30 '20 at 15:24

aled

21,330
3
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score 3 · Accepted Answer · answered Jul 30 '20 at 16:34

3

Here's yet another way:

%dw 2.0
output application/json
var o = {
    str1 : "String 1",
    str2 : "String 2",
    str3 : null,
    str4 : "String 4",
}
---
o filterObject $ != null

Here's the filterObject documentation

Pick the one you like :)

answered Jul 30 '20 at 16:34

George

2,758
12
16

JSON object Ignore null

3 Answers3