In DataWeave 2.0 functions are categorized into different modules.
- Core (dw::Core)
- Arrays (dw::core::Arrays)
- Binaries (dw::core::Binaries)
- Encryption (dw::Crypto)
- Diff (dw::util::Diff)
- Objects (dw::core::Objects)
- Runtime (dw::Runtime)
- Strings (dw::core::Strings)
- System (dw::System)
- URL (dw::core::URL)
Functions defined in Core (dw::Core) module are imported automatically into your DataWeave scripts. To use other modules, we need to import them by adding the import directive to the head of DataWeave script, for example:
import dw::core::Strings
import dasherize, underscore from dw::core::Strings
import * from dw::core::Strings
{
"firstName" : "Murali",
"lastName" : "Krishna",
"age" : "26",
“age” : ”26”
}
1. Core (dw::Core)
Below are the DataWeave 2 core functions:
++ , –, abs, avg, ceil, contains, daysBetween, distinctBy, endsWith, filter, IsBlank, joinBy, min, max etc….
result : [0, 1, 2] ++ [“a”, “b”, “c”] will gives us “result” : “[0, 1, 2, “a”, “b”, “c”]”
result : [0, 1, 1, 2] — [1,2] will gives us “result” : “[0]”
result : abs(-20) will gives us “result” : 20
average : avg([1, 1000]) will gives us “average” : 500.5
value : ceil(1.5) will gives us “value” : 2
result : payload contains “Krish” will gives us “result” : true
days: daysBetween(“2016-10-01T23:57:59-03:00”, “2017-10-01T23:57:59-03:00”) will gives us “days”: 365
age : payload distinctBy $ will gives us :
{
“firstName” : “Murali”,
“lastName” : “Krishna”,
“age” : ”26”
}
a: “Murali” endsWith “li” will gives us “a” : true
a: [1, 2, 3, 4, 5] filter($ > 2) will gives us “a” : [3,4,5]
empty: isBlank(“”) will gives us “empty” : true
aa: [“a”,”b”,”c”] joinBy “-” will gives us “a” : “a-b-c”
a: min([1, 1000]) will gives us “a” : 1
a: max([1, 1000]) will gives us “a” : 1000
2.Arrays (dw::core::Arrays)
Arrays related functions in DataWeave are :
countBy, divideBy, every, some, sumBy
[1, 2, 3] countBy (($ mod 2) == 0) will gives us 1
[1,2,3,4,5] dw::core::Arrays::divideBy 2 will gives us :
[
[
1,
2
],
[
3,
4
],
[
5
]
]
[1,2,3,4] dw::core::Arrays::every ($ == 1) will gives us “false”
[1,2,3,4] dw::core::Arrays::some ($ == 1) will gives us “true”
[ { a: 1 }, { a: 2 }, { a: 3 } ] sumBy $.a will gives us “6”
3.Binaries (dw::core::Binaries)
Binary functions in DataWeave-2 are:
fromBase64, fromHex, toBase64, toHex
toBase64(fromBase64(12463730)) will gives us “12463730”
{ “binary”: fromHex(‘4D756C65’)} will gives us “binary” : “Mule”
{ “hex” : toHex(‘Mule’) } will gives us “hex” : “4D756C65”
4.Encryption (dw::Crypto)
Encryption functions in Dataweave – 2 are:
HMACBinary, HMACWith, MD5, SHA1, hashWith
{ “HMAC”: Crypto::HMACBinary((“aa” as Binary), (“aa” as Binary)) } will gives us :
“HMAC”: “\u0007£š±]\u00adÛ\u0006‰\u0006Ôsv:ý\u000b\u0016çÜð”
Crypto::MD5(“asd” as Binary) will gives us “7815696ecbf1c96e6894b779456d330e”
Crypto::SHA1(“dsasd” as Binary) will gives us “2fa183839c954e6366c206367c9be5864e4f4a65”
5.Diff (dw::util::Diff)
It calculates difference between two values and returns list of differences.
DataWeave Script:
%dw 2.0
import * from dw::util::Diff
output application/json
var a = { age: “Test” }
var b = { age: “Test2” }
—
a diff b
Output:
{
“matches”: false,
“diffs”: [
{
“expected”: “\”Test\””,
“actual”: “\”Test2\””,
“path”: “(root).age”
}
]
}
Note:
Rest of the things will proceed in Mule – 4 DataWeave Functions Part – 2 article
