This module contains helper functions to work with Objects.

To use this module, you must import it to your DataWeave code, for example, by adding the line import * from dw::core::Objects to the header of your DataWeave script.

Functions

divideBy

divideBy(Object, Number): Array<Object>

Breaks up an object into sub-objects that contain the specified number of key-value pairs.

If there are fewer key-value pairs in an object than the specified number, the function will fill the object with those pairs. If there are more pairs, the function will fill another object with the extra pairs.

Parameters

Name Description

items

Key-value pairs in the source object.

amount

The number of key-value pairs allowed in an object.

Example

This example breaks up objects into sub-objects based on the specified amount.

Source


  
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%dw 2.0
import divideBy from dw::core::Objects
output application/json
---
{ "divideBy" : {"a": 1, "b" : true, "a" : 2, "b" : false, "c" : 3} divideBy 2 }

Output


  
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{
  "divideBy": [
    {
      "a": 1,
      "b": true
    },
    {
      "a": 2,
      "b": false
    },
    {
      "c": 3
    }
  ]
}

entrySet

entrySet(T)

Returns a list of key-value pairs that describe the key, value, and any attributes in the input object.

Parameters

Name Description

obj

The Object to describe.

Example

This example returns the key, value, and attributes in the object specified in the variable myVar.

Source


  
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%dw 2.0
import * from dw::core::Objects
var myVar = read('<xml attr="x"><a>true</a><b>1</b></xml>', 'application/xml')
output application/json
---
{ "entrySet" : entrySet(myVar) }

Output


  
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{
  "entrySet": [
    {
       "key": "xml",
       "value": {
         "a": "true",
         "b": "1"
       },
       "attributes": {
         "attr": "x"
       }
    }
  ]
}

keySet

keySet(T): ?

Returns the list of key names from an object.

Parameters

Name Description

object

The object to evaluate.

Example

This example returns the keys from the input object.

Source


  
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%dw 2.0
import * from dw::core::Objects
output application/json
---
{ "keySet" : keySet({ "a" : true, "b" : 1}) }

Output


  
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{ "keySet" : ["a","b"] }

Example

This example illustrates a difference between keySet and nameSet. Notice that keySet retains the attributes (name and lastName) and namespaces (xmlns) from the XML input, while nameSet returns null for them because it does not retain them.

Source


  
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%dw 2.0
import * from dw::core::Objects
var myVar = read('<users xmlns="http://test.com">
                     <user name="Mariano" lastName="Achaval"/>
                     <user name="Stacey" lastName="Duke"/>
                  </users>', 'application/xml')
output application/json
---
{ keySetExample: flatten([keySet(myVar.users) map $.#,
                          keySet(myVar.users) map $.@])
}
++
{ nameSet: flatten([nameSet(myVar.users) map $.#,
                    nameSet(myVar.users) map $.@])
}

Output


  
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{
  "keySet": [
    "http://test.com",
    "http://test.com",
    {
      "name": "Mariano",
      "lastName": "Achaval"
    },
    {
      "name": "Stacey",
      "lastName": "Duke"
    }
  ],
  "nameSet": [
    null,
    null,
    null,
    null
  ]
}

mergeWith

mergeWith(T, V): ?

Appends any key-value pairs from a source object to a target object.

If source and target objects have the same key, the function appends that source object to the target and removes that target object from the output.

Parameters

Name Description

source

The object to append to the target.

target

The object to which the source object is appended.

Example

This example appends the source objects to the target. Notice that "a" : true, is removed from the output, and "a" : false is appended to the target.

Source


  
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%dw 2.0
import mergeWith from dw::core::Objects
output application/json
---
{ "mergeWith" : { "a" : true, "b" : 1} mergeWith { "a" : false, "c" : "Test"} }

Output


  
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"mergeWith": {
    "b": 1,
    "a": false,
    "c": "Test"
}

mergeWith(Null, T): T

Helper method to make mergeWith null friendly.

mergeWith(T, Null): T

Helper method to make mergeWith null friendly.

nameSet

nameSet(Object): Array<String>

Returns a list of keys from an object.

Parameters

Name Description

obj

The object to evaluate.

Example

This example returns the keys from the input object.

Source


  
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%dw 2.0
import * from dw::core::Objects
output application/json
---
{ "nameSet" : nameSet({ "a" : true, "b" : 1}) }

Output


  
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{ "nameSet" : ["a","b"] }

valueSet

valueSet({ (K)?: V }): Array<V>

Returns the list of the values in an object.

Parameters

Name Description

obj

The object to evaluate.

Example

This example returns the values from the input object.

Source


  
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%dw 2.0
import dw::core::Objects
output application/json
---
{ "valueSet" : valueSet({a: true, b: 1}) }

Output


  
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{ "valueSet" : [true,1] }