This post was originally published here
I don’t know the reason why two products from the same family – Azure Integration Services – have completely different behaviors while converting XML to JSON, but that is the current reality. It is a fact! API Management and Logic Apps have different behaviors while applying this conversion, and that is one of the main reasons that I decided to create an Azure Function to convert XML into JSON, to keep the consistency between these two products.
While using API Management, we can use the xml-to-json policy to convert a request or response body from XML to JSON. However, when dealing with XML namespaces and prefixes, which is quite normal when working with XML messages, the policy has, in my opinion, a strange conversion behavior:
- It converts the prefixes that in XML are represented by prefix:MyField into prefix$MyField. In order words, it replaces the colon character (:) with the dollar character ($).
Let’s take this XML sample in order for you to see the upcome result of that xml-to-json policy:
Book-Signing Event
Convert it to JSON
The result will be:
{
"section": {
"@xmlns": "http://www.test.com/events",
"@xmlns$bk": "urn:loc.gov:books",
"@xmlns$pi": "urn:personalInformation",
"@xmlns$isbn": "urn:ISBN:0-999-99999-9",
"title": "Book-Signing Event",
"signing": {
"bk$author": {
"@pi$title": "Mr",
"@pi$name": "My Name"
},
"book": {
"@bk$title": "How cool is XML",
"@isbn$number": "9999999999"
},
"comment": {
"@xmlns": "",
"#text": "Convert it to JSON"
}
}
}
}
I think this behavior is strange and incorrect.
Now, if we take the same XML payload and try to convert it inside Logic Apps using the json() expression that returns the JSON type value or object for a string or XML. In this case, using, for example, the following expression:
- json(xml(triggerBody()))
The result will be:
{
"section": {
"@xmlns": "http://www.test.com/events",
"@xmlns:bk": "urn:loc.gov:books",
"@xmlns:pi": "urn:personalInformation",
"@xmlns:isbn": "urn:ISBN:0-999-99999-9",
"title": "Book-Signing Event",
"signing": {
"bk:author": {
"@pi:title": "Mr",
"@pi:name": "My Name"
},
"book": {
"@bk:title": "How cool is XML",
"@isbn:number": "9999999999"
},
"comment": {
"@xmlns": "",
"#text": "Convert it to JSON"
}
}
}
}
In this case, the json() expression does not replace the colon character (:) with the dollar character ($) in the prefixes. It’s maintaining, which I think is the correct behavior.
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