FHIR complex extension - hl7-fhir

Question

How can I add an extension that has multiple fields ?
For example if I have a extension related to visit motives that is structured like this in my application :
"visit_motive":
{
"id": "1",
"label": "Visit motive name",
"color": "#000000",
"duration": 5
}
I have something like this for the moment :
"extension": [
{
"url": "https://api.test.com/fhir/StructureDefinition/schedule-visit_motives",
"valueIdentifier": "visit_motive1_id",
"valueString" : "visit motive name",
"valueString" : "#000",
"valueInteger" : 5,
},
{
"url": "https://api.test.com/fhir/StructureDefinition/schedule-visit_motives",
"valueIdentifier": "visit_motive2_id",
"valueString" : "visit motive name 2",
"valueString" : "#111",
"valueInteger" : 10,
}
]
But I'm pretty sure it is not correct since I can't name the fields since I have to precise value[x] each time.
How can I do it ?

Answer 1

You would do that with a complex extension, which is basically an extension containing extensions. You can see more information about extensions in the spec. Scroll down a bit for the complex one. Or view an example of the structure of a complex extension here.
The use of your extension would look something like this:
"extension" : [{
"url" : "https://api.test.com/fhir/StructureDefinition/schedule-visit_motives",
"extension" : [{
"url" : "id",
"valueIdentifier": "visit_motive1_id"
}, {
"url" : "label",
"valueString" : "visit motive name"
}, {
"url" : "color",
"valueString" : "#000"
}, {
"url" : "duration",
"valueInteger" : 5,
}]
}]