Description
This problem is similar to the one described in issue #125. In this case, the program panics when a relationship is defined with multiple resource types. I've forked @tanmayambre's test repository and fixed it up to reproduce the issue. It's available at https://github.com/mkaminski1988/testapi2go.
Let's say I want to define an Author with a relationship named works that contains types books and blogs. The JSON API output would resemble the following:
{
"data": {
"type": "author",
"id": "100",
"attributes": {
"name": "John Doe"
},
"relationships": {
"works": {
"links": {
"self": "http://192.168.99.100:31415/author/100000004343888/relationships/works",
"related": "http://192.168.99.100:31415/author/100000004343888/works"
},
"data": [
{
"type": "books",
"id": "200"
},
{
"type": "blogs",
"id": "300"
}
]
}
}
}
}Here's how I tried to set up the GetReferences() function for the author model type:
func (author Author) GetReferences() []jsonapi.Reference {
return []jsonapi.Reference{
{
Type: "books",
Name: "works",
},
{
Type: "blogs",
Name: "works",
},
}
}The following error is produced:
panic: a handle is already registered for path '/v1/authors/:id/relationships/works'
goroutine 1 [running]:
panic(0x30f440, 0xc8201485d0)
/usr/local/go/src/runtime/panic.go:481 +0x3e6
github.com/julienschmidt/httprouter.(*node).addRoute(0xc820011cc0, 0xc82013d030, 0x13, 0xc8201485c0)
/Users/207189/dev/go/src/github.com/julienschmidt/httprouter/tree.go:193 +0xcda
github.com/julienschmidt/httprouter.(*Router).Handle(0xc820150240, 0x422190, 0x3, 0xc82013d020, 0x23, 0xc8201485c0)
/Users/207189/dev/go/src/github.com/julienschmidt/httprouter/router.go:236 +0x22b
github.com/manyminds/api2go/routing.HTTPRouter.Handle(0xc820150240, 0x422190, 0x3, 0xc82013d020, 0x23, 0xc82022c050)
/Users/207189/dev/go/src/github.com/manyminds/api2go/routing/httprouter.go:25 +0x88
github.com/manyminds/api2go/routing.(*HTTPRouter).Handle(0xc820026218, 0x422190, 0x3, 0xc82013d020, 0x23, 0xc82022c050)
<autogenerated>:1 +0xc1
github.com/manyminds/api2go.(*API).addResource(0xc82007c360, 0x1244700, 0xc82007c3f0, 0x12446c0, 0xc820026220, 0x1244700)
/Users/207189/dev/go/src/github.com/manyminds/api2go/api.go:304 +0xbf1
github.com/manyminds/api2go.(*API).AddResource(0xc82007c360, 0x1244700, 0xc82007c3f0, 0x12446c0, 0xc820026220)
/Users/207189/dev/go/src/github.com/manyminds/api2go/api_public.go:46 +0x49
main.main()
/Users/207189/dev/go/src/github.com/tanmayambre/testapi2go/main.go:14 +0x129
exit status 2
It seems that this is caused by the fact that api2go generates all the relationship routes by looping over the references returned by GetReferences(), which may contain duplicate Name fields. The routine that generates routes should work off of a de-duped list of relationship names in order to avoid duplicate routes. I have not found a restriction in the JSON API spec that disallows multiple types in a relationship, so this functionality should be supported.