将API请求函数传递给另一个函数GoLang

Question

I was making an api request on page load of a specific html template. This is causing problems so I would like to make the api call when the program runs so the data is accessible when the html page is viewed.

So I am new to GoLang and am having trouble understanding what arguments to pass to this function when I call it in main.

func RequestTopMovies(w http.ResponseWriter, r *http.Request) {
  res, err := http.Get(url)
      if err != nil {
        panic(err)
      }
      defer res.Body.Close()

      body, err := ioutil.ReadAll(res.Body)
      if err != nil {
        panic(err)
      }
      var p Payload

      err = json.Unmarshal(body, &p)
      if err != nil {
        panic(err)
      }
      for i := 0; i < len(p.Results); i++ {
       fmt.Println(p.Results[i].Overview) // Prints to your terminal
    }
}

So now at this point I have the response in p.Results.

I want to be able to access this data in other places in my program. I was thinking I could just call the function.

So how can I call this function in main?

func main() {
  RequestTopMovies(http.ResponseWriter, http.Request)
  http.HandleFunc("/", mainHandler)
  http.HandleFunc("/about", aboutHandler)
  http.HandleFunc("/TopPicks", TopMoviesHandler)
  http.ListenAndServe(":8080", nil)
}

How can I pass this function to another function to have it return the response as well?

Answer 1

RequestTopMovies is a http.Handler type which will get called automatically as a handler function aka controller.

To access the data received, either use something like context (check gorilla/context) or just create a slice or map to hold the data struct so you can access it from somewhere else in the code, i.e.

var Temp = map[string]Payload{}

And once you unmarshaled the data, store it like

Temp[key] = p

Then from else where like another handler you can grab the data like

func SomeHandler(rw http.ResponseWriter, *http.Request) {
        p := Temp[key]
        // ...
}