Skip to main content

Le language DataWeave

CSV​

%dw 2.0
output csv header=true
---
payload
%dw 2.0
output json
---
typeOf(1.545)

Selector​

{
  "name": "Ana",
  "age": 29,
  "dynamicKey": "age"
}

%dw 2.0
output json
---
{
  fixed: payload.age,
  dynamic: payload[payload.dynamicKey]
}

Multiple sélector​

https://dataweave.mulesoft.com/learn/tutorial/3.4-Multi_Value_Selector

payload.movies.*title

Descendants selector​

https://dataweave.mulesoft.com/learn/tutorial/3.5-Descendants_Selector

payload.customer..name

Operator​

https://dataweave.mulesoft.com/learn/tutorial/4.2-Logical_Operators

Flow control​

If else​

il else retourne une valeur

%dw 2.0
output json
var action = if (payload.price < 100) "buy" else "hold"
---
{
  price  : payload.price,
  action : action
}

Pattern Matching​

{
  "action": "buy"
}
%dw 2.0
output json
---
    payload.action match {
case "buy"  -> “Buy at market price"
case "sell" -> "Sell at market price"
case "hold" -> “Hold asset"
else   -> "Invalid input"
}

Functions​

%dw 2.0
output json

fun add(n, m) =
  n + m
---
add(1,2)

lambda​

%dw 2.0
output json
---
(() -> 2 + 3)()

or
%dw 2.0
output json

var add = (n, m) -> n + m
---
    add(2, 3)

Création de variable uniquement pour la fonction

%dw 2.0
output json

fun diff(n) = do {
  var start = n[0]
  var end = n[-1]
  ---
  end - start
}

---
diff([1990, 1995, 2002, 2008, 2021])

infix notation​

https://dataweave.mulesoft.com/learn/tutorial/6.4-Infix_notation

%dw 2.0
output json

var numbers = (1 to 5)
---
numbers
  filter ((n, idx) -> (n mod 2) == 1)
  filter ((n, idx) -> (n > 3))

$,$$,$$$

https://dataweave.mulesoft.com/learn/tutorial/6.5-$,_$$,_$$$_syntax

Array​

reduce​

https://dataweave.mulesoft.com/learn/tutorial/7.5-reduce

Solution​
%dw 2.0
output json
---

payload reduce ((n, total = {}) -> total ++ {(n.name):n.id} )

Challenge​

https://dataweave.mulesoft.com/learn/tutorial/7.6-Challenge

%dw 2.0
output json
var weekdays = [
  "mon",
  "tue",
  "wed",
  "thu",
  "fri",
  "sat",
  "sun"
]
// dayOfWeek is a value from 1 to 7
fun toWeekDay(date : String) : String = weekdays[(date as LocalDateTime).dayOfWeek - 1]
---
payload map ((item, index) ->  item ++ {"day":toWeekDay(item.datetime)})
filter ((n, index) -> n.organizer == "Ross")

Object​

https://dataweave.mulesoft.com/learn/tutorial/8.1-filterObject

Map object et array​

https://dataweave.mulesoft.com/learn/tutorial/8.2-mapObject

%dw 2.0
output json
---
payload map ((item, index) -> 
            item mapObject ((value, key, index) -> {(lower(key)):upper(value)})
    )

pluck​

https://dataweave.mulesoft.com/learn/tutorial/8.3-pluck

%dw 2.0
output json
---
payload groupBy ((order, index) -> order.customer ) 
pluck ((value, key, ind) -> (value))