// UserRest binds store to pat router
func UserRest(rf httpservice.RouterFunc, paths httpservice.Paths, patches ...httpservice.ServicesPatch) {
log.Printf("REST path: %s", paths.Plural())
// generate CRUD endpoints
endpoints := UserStoreEndpoints(
paths.Noun().Singular(), paths.Noun().Plural())
// generate service description (Middleware, DecodeRequestFunc)
services := UserStoreServices(paths, endpoints)
services.Patch(patches...)
// route to all services
if err := services.Route(rf); err != nil {
panic(err)
}
}
func UserStoreServices(paths httpservice.Paths, endpoints map[string]endpoint.Endpoint) (handlers httpservice.Services) {
// variables to use later
noun := paths.Noun()
storeKey := KeyUser
getStore := func(ctx context.Context) (s *UserStore, err error) {
raw, err := store.Get(ctx, storeKey)
if err != nil {
return
}
s, ok := raw.(*UserStore)
if !ok {
err = fmt.Errorf(`store.Get(KeyUser) does not return *KeyUser`)
return
}
return
}
// define default middlewares
var prepareCreate endpoint.Middleware = func(inner endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (respond interface{}, err error) {
// placeholder: anything you want to do with the entity
// before append to database
httpservice.EnforceCreate(request)
return inner(ctx, request)
}
}
var prepareUpdate endpoint.Middleware = func(inner endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (response interface{}, err error) {
sReq := request.(*httpservice.Request)
// get context information
r := gourdctx.HTTPRequest(ctx)
if r == nil {
serr := store.ErrorInternal
serr.ServerMsg = "missing request in context"
err = serr
return
}
el := &[]User{}
q := sReq.Query
// get store
s, err := getStore(ctx)
if err != nil {
serr := store.ErrorInternal
serr.ServerMsg = fmt.Sprintf("error obtaining %s store (%s)", storeKey, err)
err = serr
return
}
defer s.Close()
// find the previous content of the id
err = s.Search(q).All(el)
if err != nil {
serr := store.ErrorInternal
serr.ServerMsg = fmt.Sprintf("error searching %s: %s",
noun.Singular(), err)
err = serr
return
}
// tell the inner
if len(*el) > 0 {
sReq.Previous = &(*el)[0]
}
// enforce agreement on sReq.Payload with previous sReq.Entity
httpservice.EnforceUpdate(sReq.Previous, sReq.Payload)
// placeholder: anything you want to do with the entity
// before update to database
return inner(ctx, sReq)
}
}
var prepareList endpoint.Middleware = func(inner endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (response interface{}, err error) {
response, err = inner(ctx, request)
if err != nil {
return
}
vmap := response.(map[string]interface{})
list := vmap[noun.Plural()].(*[]User)
if list == nil || *list == nil {
*list = make([]User, 0)
}
vmap[noun.Plural()] = list
// placeholder: anything you want to do with the entity
// list response
return vmap, nil
}
}
// wrap inner response with default protocol
var prepareProtocol endpoint.Middleware = func(inner endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (response interface{}, err error) {
v, err := inner(ctx, request)
if err != nil {
return
}
switch v.(type) {
case map[string]interface{}:
response = store.ExpandResponse(v.(map[string]interface{}))
default:
response = store.NewResponse(noun.Plural(), v)
}
return
}
}
// generates response permission checker middleware
checkPermBefore := func(permission string) endpoint.Middleware {
return func(inner endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (response interface{}, err error) {
m := perm.GetMux(ctx)
err = m.Allow(ctx, permission, request)
if err != nil {
return
}
return inner(ctx, request)
}
}
}
// generates request permission checker middleware
checkPermAfter := func(permission string) endpoint.Middleware {
return func(inner endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (response interface{}, err error) {
v, err := inner(ctx, request)
if err != nil {
return
}
m := perm.GetMux(ctx)
err = m.Allow(ctx, permission, request, v)
if err != nil {
return
}
response = v
return
}
}
}
//
// ==== raw decode functions
//
decodeServiceIDReq := func(ctx context.Context, r *http.Request) (request *httpservice.Request, err error) {
id := r.URL.Query().Get(":id") // will change
cond := store.NewConds().Add("id", id)
request = &httpservice.Request{
Request: r,
Query: store.NewQuery().SetConds(cond),
}
return
}
decodeJSONEntity := func(ctx context.Context, r *http.Request) (entity *User, err error) {
// allocate entity
entity = &User{}
// decode request
dec := json.NewDecoder(r.Body)
err = dec.Decode(entity)
return
}
//
// ==== httptransport.DecodeRequestFunc implementations
//
// decodeIDReq generically decoded :id field
// (works with pat based URL routing, router specific)
var decodeIDReq httptransport.DecodeRequestFunc = func(ctx context.Context, r *http.Request) (request interface{}, err error) {
return decodeServiceIDReq(ctx, r)
}
// decodeListReq decode query for list endpoint
var decodeListReq httptransport.DecodeRequestFunc = func(ctx context.Context, r *http.Request) (request interface{}, err error) {
sReq := &httpservice.Request{
Request: r,
Query: store.NewQuery(),
}
// parse sort parameter
sortStr := r.FormValue("sorts")
if sortStr != "" {
sorts := strings.Split(sortStr, ",")
for _, sort := range sorts {
sReq.Query.Sort(sort)
}
}
// parse paging request parameter
offset, limit := func(r *http.Request) (o, l uint64) {
ostr := r.FormValue("offset")
lstr := r.FormValue("limit")
if ostr != "" {
if ot, err := strconv.ParseUint(ostr, 10, 64); err == nil {
o = ot
}
}
if lstr != "" {
if lt, err := strconv.ParseUint(lstr, 10, 64); err == nil {
l = lt
}
}
return
}(r)
// retrieve
sReq.Query.SetOffset(offset)
sReq.Query.SetLimit(limit)
request = sReq
return
}
// decodeJSONReq returns a DecodeRequestFunc that decode request
// into allocated memory structure
var decodeJSONReq httptransport.DecodeRequestFunc = func(ctx context.Context, r *http.Request) (request interface{}, err error) {
return decodeJSONEntity(ctx, r)
}
// decodeUpdate returns a DecodeRequestFunc that decode request
var decodeUpdate httptransport.DecodeRequestFunc = func(ctx context.Context, r *http.Request) (request interface{}, err error) {
sReq, err := decodeServiceIDReq(ctx, r)
if err != nil {
return
}
sReq.Payload, err = decodeJSONEntity(ctx, r)
if err != nil {
return
}
request = sReq
return
}
//
// ==== httpservce.Services
//
// define middleware chains of all RESTful endpoints
handlers = make(map[string]*httpservice.Service)
handlers["create"] = httpservice.NewJSONService(
paths.Plural(), endpoints["create"])
handlers["create"].Weight = 1
handlers["create"].Methods = []string{"POST"}
handlers["create"].DecodeFunc = decodeJSONReq
handlers["create"].Middlewares.Add(httpservice.MWProtocol, prepareProtocol)
handlers["create"].Middlewares.Add(httpservice.MWPrepare, prepareCreate)
handlers["create"].Middlewares.Add(httpservice.MWInner,
checkPermBefore("create "+noun.Singular()))
handlers["retrieve"] = httpservice.NewJSONService(
paths.Singular(), endpoints["retrieve"])
handlers["retrieve"].Methods = []string{"GET"}
handlers["retrieve"].DecodeFunc = decodeIDReq
handlers["retrieve"].Middlewares.Add(httpservice.MWProtocol, prepareProtocol)
handlers["retrieve"].Middlewares.Add(httpservice.MWPrepare, prepareList)
handlers["retrieve"].Middlewares.Add(httpservice.MWInner,
checkPermAfter("retrieve "+noun.Singular()))
handlers["update"] = httpservice.NewJSONService(
paths.Singular(), endpoints["update"])
handlers["update"].Methods = []string{"PUT"}
handlers["update"].DecodeFunc = decodeUpdate
handlers["update"].Middlewares.Add(httpservice.MWProtocol, prepareProtocol)
handlers["update"].Middlewares.Add(httpservice.MWPrepare, prepareUpdate)
handlers["update"].Middlewares.Add(httpservice.MWInner,
checkPermBefore("update "+noun.Singular()))
handlers["list"] = httpservice.NewJSONService(
paths.Plural(), endpoints["list"])
handlers["list"].Weight = 1
handlers["list"].Methods = []string{"GET"}
handlers["list"].DecodeFunc = decodeListReq
handlers["list"].Middlewares.Add(httpservice.MWProtocol, prepareProtocol)
handlers["list"].Middlewares.Add(httpservice.MWPrepare, prepareList)
handlers["list"].Middlewares.Add(httpservice.MWInner,
checkPermAfter("list "+noun.Singular()))
handlers["delete"] = httpservice.NewJSONService(
paths.Singular(), endpoints["delete"])
handlers["delete"].Methods = []string{"DELETE"}
handlers["delete"].DecodeFunc = decodeIDReq
handlers["delete"].Middlewares.Add(httpservice.MWProtocol, prepareProtocol)
handlers["delete"].Middlewares.Add(httpservice.MWInner,
checkPermBefore("delete "+noun.Singular()))
return
}