I adapted arcgis-map widget to make it one of my custom widgets.
In the development ide, in arcgis-map "Content" tab (which is handled by setting.tsx), I added a new config element, which is a json array of objects, so in the text area I write it:
[
{
"param1": "string1-1",
"param2":"string1-2",
"param3":250},
{
"param1": "string2-1",
"param2": "string2-1",
"param3":100
}
]
I managed that it will work well, but there is an "ugliness" problem:
When I create and expand the zip file, then:
In the application config it appears as if it is a string:
"newElement": "[\n {\n \"param1\": \"string1-1\",\n \"param2\": \"string1-2\",\n \"param3\": 10\n },\n {\n \"param1\": \"string2-1\",\n \"param2\": \"string2-2\",\n \"param3\": 200\n }\n]"