quickstart

https://developers.google.com/sheets/api/quickstart/go

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

main.go

@@ -0,0 +1,109 @@
+package main
+
+import (
+        "encoding/json"
+        "fmt"
+        "io/ioutil"
+        "log"
+        "net/http"
+        "os"
+
+        "golang.org/x/net/context"
+        "golang.org/x/oauth2"
+        "golang.org/x/oauth2/google"
+        "google.golang.org/api/sheets/v4"
+)
+
+// Retrieve a token, saves the token, then returns the generated client.
+func getClient(config *oauth2.Config) *http.Client {
+        // The file token.json stores the user's access and refresh tokens, and is
+        // created automatically when the authorization flow completes for the first
+        // time.
+        tokFile := "token.json"
+        tok, err := tokenFromFile(tokFile)
+        if err != nil {
+                tok = getTokenFromWeb(config)
+                saveToken(tokFile, tok)
+        }
+        return config.Client(context.Background(), tok)
+}
+
+// Request a token from the web, then returns the retrieved token.
+func getTokenFromWeb(config *oauth2.Config) *oauth2.Token {
+        authURL := config.AuthCodeURL("state-token", oauth2.AccessTypeOffline)
+        fmt.Printf("Go to the following link in your browser then type the "+
+                "authorization code: \n%v\n", authURL)
+
+        var authCode string
+        if _, err := fmt.Scan(&authCode); err != nil {
+                log.Fatalf("Unable to read authorization code: %v", err)
+        }
+
+        tok, err := config.Exchange(context.TODO(), authCode)
+        if err != nil {
+                log.Fatalf("Unable to retrieve token from web: %v", err)
+        }
+        return tok
+}
+
+// Retrieves a token from a local file.
+func tokenFromFile(file string) (*oauth2.Token, error) {
+        f, err := os.Open(file)
+        if err != nil {
+                return nil, err
+        }
+        defer f.Close()
+        tok := &oauth2.Token{}
+        err = json.NewDecoder(f).Decode(tok)
+        return tok, err
+}
+
+// Saves a token to a file path.
+func saveToken(path string, token *oauth2.Token) {
+        fmt.Printf("Saving credential file to: %s\n", path)
+        f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+        if err != nil {
+                log.Fatalf("Unable to cache oauth token: %v", err)
+        }
+        defer f.Close()
+        json.NewEncoder(f).Encode(token)
+}
+
+func main() {
+        b, err := ioutil.ReadFile("credentials.json")
+        if err != nil {
+                log.Fatalf("Unable to read client secret file: %v", err)
+        }
+
+        // If modifying these scopes, delete your previously saved token.json.
+        config, err := google.ConfigFromJSON(b, "https://www.googleapis.com/auth/spreadsheets.readonly")
+        if err != nil {
+                log.Fatalf("Unable to parse client secret file to config: %v", err)
+        }
+        client := getClient(config)
+
+        srv, err := sheets.New(client)
+        if err != nil {
+                log.Fatalf("Unable to retrieve Sheets client: %v", err)
+        }
+
+        // Prints the names and majors of students in a sample spreadsheet:
+        // https://docs.google.com/spreadsheets/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit
+        spreadsheetId := "1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms"
+        readRange := "Class Data!A2:E"
+        resp, err := srv.Spreadsheets.Values.Get(spreadsheetId, readRange).Do()
+        if err != nil {
+                log.Fatalf("Unable to retrieve data from sheet: %v", err)
+        }
+
+        if len(resp.Values) == 0 {
+                fmt.Println("No data found.")
+        } else {
+                fmt.Println("Name, Major:")
+                for _, row := range resp.Values {
+                        // Print columns A and E, which correspond to indices 0 and 4.
+                        fmt.Printf("%s, %s\n", row[0], row[4])
+                }
+        }
+}
+