Siesta: RESTful Services Made Simple

Slides from a beCraft talk in Charlottesville on Nov. 12 2015.

Transcript

2. ◦
3. ◦ ◦ ◦ ◦ ◦ ◦
4. func h(w http.ResponseWriter, r *http.Request) { } Boilerplate code (logging, auth, parameters) Boilerplate code (response writing, etc) Main handler code
5. func h(w http.ResponseWriter, r *http.Request) { f(w, r) { } g(w, r) { } } Boilerplate code (logging, auth, parameters) Boilerplate code (response writing, etc) Main handler code
6. func f(w http.ResponseWriter, r *http.Request) { } func h(w http.ResponseWriter, r *http.Request) { } func g(w http.ResponseWriter, r *http.Request) { } Boilerplate code (logging, auth, parameters) Boilerplate code (response writing, etc) Main handler code
7. func(c siesta.Context, w http.ResponseWriter, r *http.Request) { // set interface{}s c.Set("foo", bar); // get interface{}s c.Get("foo") // => interface{}(bar) } ◦ ◦
8. gorilla/context ◦ ◦ ◦ func MyHandler(w http.ResponseWriter, r *http.Request) { // ... requestID := context.Get(r, "request-id") // ... }
12. func (s *Service) ServeHTTPInContext(c Context, w http.ResponseWriter, r *http.Request) { // ... quit := false for _, m := range s.pre { // s.pre is a slice of handlers m(c, w, r, func() { quit = true }) if quit { break } } // ... }
13. flags ◦ GET /resources/:resourceID/things?all=true ◦ params.Int("resourceID", …) ◦ params.Bool("all", …)
14. var params siesta.Params // GET /resources/:resourceID/... resourceID := params.Int("resourceID", -1, "Resource identifier") err := params.Parse(r.Form) if err != nil { // Do something with the err } // Make sure we have a valid resource ID. if *resourceID == -1 { // Handle the invalid resource }
17. // responseGenerator converts response and/or error data passed through the // context into a structured response. func responseGenerator(c siesta.Context, w http.ResponseWriter, r *http.Request) { response := apiResponse{} if data := c.Get("data"); data != nil { response.Data = data } if err := c.Get("error"); err != nil { response.Error = err.(string) } c.Set("response", response) }
18. func TestHandler(t *testing.T) { c := siesta.NewSiestaContext() // c.Set(...) myHandler(c, mockResponseWriter, &http.Request{ Form: url.Values(map[string][]string{ "id": []string{"1"}, // maybe a GET /resource/:id }), } // c.Get(...) }
19. database/sql ◦ ◦ ◦ ◦
20. ◦
21. sql.DB sql.Tx sql. DB sql.Tx ◦ database/sql sql.DB sql.Tx
22. sql.DB type SQLDB interface { Query(query string, args ...interface{}) (SQLRows, error) QueryRow(query string, args ...interface{}) SQLRow Exec(query string, args ...interface{}) (sql.Result, error) Begin() error Rollback() error Commit() error } type SQLRows interface { SQLRow Close() error Err() error Next() bool } type SQLRow interface { Scan(dest ...interface{}) error }
23. type DB struct { sqlDB *sql.DB tx *sql.Tx context siesta.Context } func (db *DB) Query(query string, args ...interface{}) (Rows, error) { // db.context is accessible! if db.tx != nil { return db.tx.Query(query, args...) } return db.sqlDB.Query(query, args...) } // ...
25. $ curl localhost:8080/resources/1 -u abcde: { "data": "foo" } $ curl localhost:8080/resources/1?usage -u abcde: { "data": { "resourceID": [ "resourceID", "int", "Resource identifier" ], "usage": [ "usage", "bool", "Show usage" ] } } Name Type Description
26. // Check parameters var params siesta.Params resourceID := params.Int("resourceID", -1, "Resource identifier") params.Bool("usage", false, "Show usage") if r.URL.Query()["usage"] != nil { c.Set("data", params.Usage()) return } err := params.Parse(r.Form) // ...
27. /resources/:resourceID?summary=true { "method": "GET", "url": [ { "name": "resources", "type": "fixed" }, { "name": "resourceID", "type": "parameter" "parameterType": "int", "description": "Resource ID" } ], "queryString": [ { "name": "summary", "parameterType": "bool", "description": "Show only feature summary" } ], "endpoint": "/resources/:resourceID" }