// +build ignore,OMIT // The server program issues Google search requests. It serves on port 8080. // // The /search endpoint accepts these query params: // q=the Google search query // // For example, http://localhost:8080/search?q=golang serves the first // few Google search results for "golang". package main import ( "encoding/json" "fmt" "html/template" "log" "net/http" "time" "golang.org/x/talks/content/2016/applicative/google" ) func main() { http.HandleFunc("/search", handleSearch) // HL fmt.Println("serving on http://localhost:8080/search") log.Fatal(http.ListenAndServe("localhost:8080", nil)) } // handleSearch handles URLs like "/search?q=golang" by running a // Google search for "golang" and writing the results as HTML to w. // The query parameter "output" selects alternate output formats: // "json" for JSON, "prettyjson" for human-readable JSON. func handleSearch(w http.ResponseWriter, req *http.Request) { // HL log.Println("serving", req.URL) // Check the search query. query := req.FormValue("q") // HL if query == "" { http.Error(w, `missing "q" URL parameter`, http.StatusBadRequest) return } // ENDQUERY OMIT // Run the Google search. start := time.Now() results, err := google.Search(query) // HL elapsed := time.Since(start) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } // ENDSEARCH OMIT // Create the structured response. type response struct { Results []google.Result Elapsed time.Duration } resp := response{results, elapsed} // HL // ENDRESPONSE OMIT // Render the response. switch req.FormValue("output") { case "json": err = json.NewEncoder(w).Encode(resp) // HL case "prettyjson": var b []byte b, err = json.MarshalIndent(resp, "", " ") // HL if err == nil { _, err = w.Write(b) } default: // HTML err = responseTemplate.Execute(w, resp) // HL } // ENDRENDER OMIT if err != nil { log.Print(err) return } } var responseTemplate = template.Must(template.New("results").Parse(`

{{.Title}} - {{.URL}}

{{len .Results}} results in {{.Elapsed}}

`))