Data Weave 中的条件串联

Question

有没有办法对字符串进行条件连接。例如，如果字符串有值则添加它，但如果字符串为空则不添加。我正在创建一个长字符串，它将成为电子邮件的正文。 “payload.eachRecipient.company”字段可能有一个值，也可能为空。我只想在电子邮件中包含该行，如果它有值，但如果没有，则不显示“公司名称：”行。

payload.eachRecipient.city ++ ", " ++ payload.eachRecipient.state ++ " " ++ payload.eachRecipient.zipCode ++ "\n\n" ++
("Company Name: " ++ payload.eachRecipient.company (if payload.eachRecipient.company?)) ++ "\n" ++ "ID: " ++ payload.eachRecipient.sson ++ "\n" ++ "System Order Number: " ++ payload.eachRecipient.orderNum ++ "\n\n" ++
"Shipping Method: " ++ payload.eachRecipient.ShipVia ++ "\n\n" ++ "Order Summary:\n" ++ (vars.listOfMaterials.combinedString joinBy("\n")) ++

Answer 1

条件串联工作得很好

%dw 2.0
output application/json
---
'one ' 
++ ' two ' 
++ (if (true) ' three' else ' THREE')
++ (if (false) ' four' else ' FOUR')

Answer 2

我编写了一个函数，它接受将检查空值的字符串，任何你想添加到前面的东西和任何你想添加到后面的东西：

fun checkNull(aString, aFront, aBack) = 
    if (aString == null)
        ""
    else
        aFront ++ aString ++ aBack

函数的结果连接成更长的字符串：

(checkNull(payload.eachRecipient.company, "Company Name: ", "\n"))
checkNull(payload.eachRecipient.line2, "", "\n\t")

Data Weave 中的条件串联

Conditional concatenation in Data Weave

concatenation

anypoint-studio

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