You are misunderstanding how JSON works. It is not a Document (or a tree object). It is a String that is structured in a tree. It doesn't matter if that tree looks like this....
{
"glossary": {
"title": "example glossary",
"GlossDiv": {
"title": "S",
"GlossList": {
"GlossEntry": {
"ID": "SGML",
"SortAs": "SGML",
"GlossTerm": "Standard Generalized Markup Language",
"Acronym": "SGML",
"Abbrev": "ISO 8879:1986",
"GlossDef": {
"para": "A meta-markup language, used to create markup languages such as DocBook.",
"GlossSeeAlso": ["GML", "XML"]
},
"GlossSee": "markup"
}
}
}
}
}
....or looks like this.....
{"glossary": {"title": "example glossary","GlossDiv": {"title": "S","GlossList": {"GlossEntry": {"ID": "SGML","SortAs": "SGML","GlossTerm": "Standard Generalized Markup Language","Acronym": "SGML","Abbrev": "ISO 8879:1986","GlossDef": {"para": "A meta-markup language, used to create markup languages such as DocBook.","GlossSeeAlso": ["GML", "XML"]},"GlossSee": "markup"}}}}}
....it is exactly the same and will be parsed by a proper JSON parser.
The tExtractJSONFields component uses a proper parser, you just need to use the correct JSONPath syntax. You can learn about this online. Try here: https://www.pluralsight.com/blog/tutorials/introduction-to-jsonpath
I'm afraid interacting isn't easy when you start. There just isn't a way that you can get away with not struggling for a bit. You can maybe get your REST service to return XML, that will give you a tree object.
