Allow different names for swagger specs

In the case where we need to include multiple docs packages in the same
process, swag.Register will fail. Despite looking like having support
for swagger specs with different names it actually does not work.

Define RegisterName and ReadDocName functions which allow you to specify
the name of the swag. Default method will still use this path but with
the 'classic' swag name of 'swagger'.

gen/gen.go

@@ -310,6 +310,6 @@ func (s *s) ReadDoc() string {
 }
 
 func init() {
- swag.Register(swag.Name, &s{})
+ swag.Register({{ printf "%q + %q" .Host .BasePath}}, &s{})
 }
 `

swagger.go

@@ -2,6 +2,7 @@ package swag
 
 import (
  "errors"
+ "fmt"
  "sync"
 )
 
@@ -10,7 +11,7 @@ const Name = "swagger"
 
 var (
  swaggerMu sync.RWMutex
- swag  Swagger
+ swags map[string]Swagger
 )
 
 // Swagger is a interface to read swagger document.
@@ -22,20 +23,33 @@ type Swagger interface {
 func Register(name string, swagger Swagger) {
  swaggerMu.Lock()
  defer swaggerMu.Unlock()
+
  if swagger == nil {
  panic("swagger is nil")
  }
 
- if swag != nil {
+ if swags == nil {
+ swags = make(map[string]Swagger)
+ }
+
+ if _, ok := swags[name]; ok {
  panic("Register called twice for swag: " + name)
  }
- swag = swagger
+ swags[name] = swagger
 }
 
 // ReadDoc reads swagger document.
 func ReadDoc() (string, error) {
- if swag != nil {
+ return ReadDocName(Name)
+}
+
+// ReadDocName reads swagger document with specific name.
+func ReadDocName(name string) (string, error) {
+ if swags == nil {
+ return "", errors.New("no swag has yet been registered")
+ } else if swag, ok := swags[name]; !ok {
+ return "", fmt.Errorf("no swag named \"%s\" was registered", name)
+ } else {
  return swag.ReadDoc(), nil
  }
- return "", errors.New("not yet registered swag")
 }

swagger_test.go

@@ -185,5 +185,5 @@ func TestCalledTwicelRegister(t *testing.T) {
 }
 
 func setup() {
- swag = nil
+ swags = make(map[string]Swagger)
 }