@andrewhenderson The feature you’re proposing could definitely be useful, and you’re right that having multiple question marks is valid in a URI’s query string. But having question marks as part of the
?include parameter’s value in JSON API is not. From the spec:
The value of the include parameter MUST be a comma-separated (U+002C COMMA, “,”) list of relationship paths. A relationship path is a dot-separated (U+002E FULL-STOP, “.”) list of relationship names.
Also, the same resource can be linked from multiple relationships, but it’ll only show up in
"included" once (that’s the point), so you’d have to define how to handle this case. For example, imagine a request like
GET /articles?include=author,editor where the same person is sometimes an author and sometimes an editor; which rules should this person be sorted under?
But I guess the bottom line here is that the spec gives each API total freedom to define whatever query parameter(s) it wants (as long as they contain a non-a to z character) to sort the included collection however it wants.