How do you fetch weather data from the Google Maps Platform? - google-maps

Question

I have a list of locations and I want to know if it's possible to get weather data from the Google Maps API.

Answer 1

When I've had to do this in Go, I've done something like this:
package main
import (
"bufio"
"context"
"database/sql"
"encoding/json"
"flag"
"fmt"
"io/ioutil"
"log"
"net/http"
"os"
"strings"
"sync"
"time"
"googlemaps.github.io/maps"
_ "github.com/lib/pq"
)
var db *sql.DB
var (
apiKey string
dsn string
locationsFile string
)
type HourlyForecast struct {
Type string
Properties Properties
}
type Properties struct {
Periods []Period
}
type Period struct {
Temperature int
}
func main() {
flag.StringVar(&apiKey, "api-key", "", "Google Maps API key")
flag.StringVar(&dsn, "dsn", "", "The database connection string")
flag.StringVar(&locationsFile, "locations", "locations.txt", "The locations file")
flag.Parse()
if apiKey == "" {
apiKey = os.Getenv("GOOGLE_MAPS_API_KEY")
}
if apiKey == "" {
log.Fatal("The --api-key flag or GOOGLE_MAPS_API_KEY env var must be set and non-empty")
}
apiKey = strings.TrimSpace(apiKey)
if dsn == "" {
dsn = os.Getenv("DSN")
}
var err error
db, err = sql.Open("postgres", dsn)
if err != nil {
log.Fatal(err)
}
for {
err := db.Ping()
if err != nil {
log.Println(err.Error())
time.Sleep(3 * time.Second)
continue
}
break
}
data, err := os.Open(locationsFile)
if err != nil {
log.Fatal(err)
}
var locations []string
scanner := bufio.NewScanner(data)
for scanner.Scan() {
locations = append(locations, scanner.Text())
}
var wg sync.WaitGroup
for _, location := range locations {
wg.Add(1)
location := location
go func() {
defer wg.Done()
mc, err := maps.NewClient(maps.WithAPIKey(apiKey))
if err != nil {
log.Fatal(err)
}
r := maps.FindPlaceFromTextRequest{
Input: location,
InputType: maps.FindPlaceFromTextInputTypeTextQuery,
}
response, err := mc.FindPlaceFromText(context.Background(), &r)
if err != nil {
log.Fatal(err)
}
pdr := maps.PlaceDetailsRequest{
PlaceID: response.Candidates[0].PlaceID,
}
log.Printf("retrieving geo coordinates for %s", location)
pdResponse, err := mc.PlaceDetails(context.Background(), &pdr)
if err != nil {
log.Fatal(err)
}
lat := pdResponse.Geometry.Location.Lat
lng := pdResponse.Geometry.Location.Lng
u := fmt.Sprintf("https://api.weather.gov/points/%.4f,%.4f/forecast/hourly", lat, lng)
log.Printf("retrieving weather data for %s (%.4f,%.4f)", location, lat, lng)
request, err := http.NewRequest("GET", u, nil)
if err != nil {
log.Fatal(err)
}
request.Header.Add("User-Agent", "Hightower Weather 1.0")
request.Header.Add("Accept", "application/geo+json")
weatherResponse, err := http.DefaultClient.Do(request)
if err != nil {
log.Fatal(err)
}
data, err := ioutil.ReadAll(weatherResponse.Body)
if err != nil {
log.Fatal(err)
}
weatherResponse.Body.Close()
var forecast HourlyForecast
if err := json.Unmarshal(data, &forecast); err != nil {
log.Fatal(err)
}
log.Printf("setting temperature for %s to %d", location, forecast.Properties.Periods[0].Temperature)
_, err = db.Exec(query, location, forecast.Properties.Periods[0].Temperature)
if err != nil {
log.Fatal(err)
}
}()
}
wg.Wait()
}
var query = `INSERT INTO weather (location, temperature)
VALUES ($1, $2)
ON CONFLICT (location)
DO UPDATE SET temperature = EXCLUDED.temperature;`