Mule 4 DataWeave Functions: Part 2

1. Objects (dw::core::Objects)
DataWeave 2.0 Object related functions are: divideBy, entrySet, mergeWith, nameSet & valueSet.

• • divideBy:

Divides object into sub-objects with properties.

dwl script:
{a: 1, b: true, a:2, b:false} divideBy 2
Output:

[
   {
     "a": 123,
     "b": true
   },
   {
     "a": 123,
     "b": false
   }
 ]

• • entrySet:

Returns list of key-value pair objects.

dwl script:
Objects::entrySet({a: true, b: 1})
Output:

[
 {
   key: "a",
   value: true,
   attributes: null
 },
 {
   key: "b",
   value: 1,
   attributes: null
 }
]

• • mergeWith:

Keeps the target object as constant, then appends to that with the source key-value pairs.

dwl script:
{a: false, b: 2} mergeWith {a: true, c: "Hello"}
Output:
{"a": true, "b": 2 , "c": "Hello"}

• • nameSet:

Returns list of key names from an object.

dwl script:
Objects::nameSet({a: true, b: 1})
Output:
["a", "b"]

• • valueSet:

Returns list of key values of an object.

dwl script:
Objects::valueSet({a: true, b: 1})
Output:
[true,1]

2. Runtime (dw::Runtime)

Runtime related functions are fail, failif & wait ….. These should be imported into DataWeave code by adding import dw::Runtime at header.

• • fail:

Throws an exception with specified message.

dwl script:
%dw 2.0
import dw::Runtime
---
Runtime::fail("Timeout Error")
Output:
Timeout Error

• • failif:

Returns an exception with the specified message if defined expression evaluates true. If not, returns the value.

dwl script:
%dw 2.0
import failIf from dw::Runtime
output application/json
---
{ "a" : "b" } failIf ("b" is String)
Output:
Failed

• • wait:

Stops execution for the specified timeout.

dwl script:
%dw 2.0
import * from dw::Runtime
output application/json
---
{user: 1} wait 2000

Output:
{
"user": 1
}

3. Strings (dw::core::Strings)

String related functions are camelize, capitalize, dasherize, pluralize & underscore … etc.

• • camelize:

a: camelize(“murali_thuraka”) will gives : “a” : “muraliThuraka”

• • capitalize:

a: capitalize(“murali_thuraka”) will gives : “a” : “MuraliThuraka”

• • dasherize:

a: dasherize(“Murali Thuraka”) will gives : “a” : “Murali-Thuraka”

• • pluralize:

a: pluralize(“box”) will gives : “a” : “boxes”

• • underscore:

a: underscore(“Murali Thuraka”) will gives : “a” : “Murali_Thuraka”

4. System (dw::System)

System-related functions are: envVar & envVars.

• • envVar:

Returns an environment variable with a specified name.

dwl script:
%dw 2.0
import dw::System
output application/json
---
System::envVar("SYS_PSWD")

• • envVars:

Returns all environment variables defined in the hosted system.

dwl script:
%dw 2.0
import dw::System
output application/json
---
System::envVars().SYS_PSWD

5. URL (dw::core::URL)

URL related functions are: compose, decodeURI & parseURI ….etc

• • compose:

It is used to replace URL components by encodeURIcomponent result of it.

dwl script:
%dw 2.0
import * from dw::core::URL
output application/json
---
{ 'composition': compose `encoding http://asd/$(' Welcome to Mule - 4 ')/text now` }

Output:
{
"composition": "encoding http://asd/%20Welcome%20to%20Mule - 4%20/text now"
}

• • decodeURI:

It decodes a Uniform Resource Identifier (URI) means that Replaces each escape sequence in the encoded URI with the character that it represents.

dwl script:
%dw 2.0
import * from dw::core::URL
output application/json
---
{
a: decodeURI('http://asd/%20text%20to%20decode%20/text')
}

Output:
{
"a": "http://asd/ text to decode /text"
}

• • parseURI:

Parses an URL and returns a URI object.

dwl script:
%dw 2.0
import * from dw::core::URL
output application/json
---
{
'composition': parseURI('https://en.wikipedia.org/wiki/Uniform_Resource_Identifier#footer')
}

Output:

{
  "composition": {
    "isValid": true,
    "raw": "https://en.wikipedia.org/wiki/Uniform_Resource_Identifier#footer",
    "host": "en.wikipedia.org",
    "authority": "en.wikipedia.org",
    "fragment": "footer",
    "path": "/wiki/Uniform_Resource_Identifier",
    "scheme": "https",
    "isAbsolute": true,
    "isOpaque": false
  }
}

For Mule 4 DataWeave Functions: Part 1

Are you still having issues with Mule 4 DataWeave functions? You can find more information in our MuleSoft blog. Our MuleSoft implementation and integration experts are here to help you. Contact us today.