Parse many data from api to html with golang-CodePudding

I am new in Go language so I have a question. I have API from where I need to parse information to cards. I have a script which GET all information from API and place it into fields in card. I understand how to take one part of information. But I need to create many cards with different information from API and place them on HTML page. How I can do this?

server.go file for HTML hosting.

package main

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "os"
    "text/template"
)

type Response struct {
    Artists   string `json:"artists"`
    Locations string `json:"locations"`
    Dates     string `json:"dates"`
    Relation  string `json:"relation"`
}
type Artist struct {
    ID           int      `json:"id"`
    Image        string   `json:"image"`
    Name         string   `json:"name"`
    Members      []string `json:"members"`
    CreationDate string   `json:"creationDate"`
    FirstAlbum   string   `json:"firstAlbum"`
}

func main() {
    http.HandleFunc("/", formHandler) // to define the path/page, where we are going to use the mentioned function
    fmt.Printf("Starting server at port 8080\n")
    if err := http.ListenAndServe(":8080", nil); err != nil { //to initialise our server on :8080
        log.Fatal("HTTP status 500 - Internal server error: %s", err)
    }
}
func formHandler(w http.ResponseWriter, r *http.Request) {
    response, err := http.Get("https://groupietrackers.herokuapp.com/api")
    if err != nil {
        fmt.Print(err.Error())
        os.Exit(1)
    }

    responseData, err := ioutil.ReadAll(response.Body)
    if err != nil {
        log.Fatal(err)
    }

    var responseObject Response

    json.Unmarshal(responseData, &responseObject)
    artist_link, err := http.Get(responseObject.Artists)
    if err != nil {
        fmt.Print(err.Error())
        os.Exit(1)
    }

    artistData, err := ioutil.ReadAll(artist_link.Body)
    if err != nil {
        log.Fatal(err)
    }

    var artistObject Artist

    json.Unmarshal(artistData, &artistObject)
    t, _ := template.ParseFiles("index.html")
    t.Execute(w, artistObject)
}

index.html file for showing information to pearson.

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title></title>
</head>
<style>
    iframe {
        width: 99vw;
    }
    .card {
  box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2);
  transition: 0.3s;
  width: 40%;
}

.card:hover {
  box-shadow: 0 8px 16px 0 rgba(0,0,0,0.2);
}

.container {
  padding: 2px 16px;
}
    </style>
    
<body>

  <header>
    <h1>groupie-tracker</h1>
     </header>
    <div>
      {{range .}}
            <div >
                <div >
                  <h4><b>{{ .Name }}</b></h4> 
                  <p>{{ .FirstAlbum }}</p> 
                </div>
              </div>
              {{end}}
     </div>
</body>

</html>

CodePudding user response：

There are a couple ways to handle templates. But you definitely want to parse your files once and store them.

One way is to create a global var and store the template/templates in there.

Also you expect a slice of Artist structs, correct? So you want to unmarshal into a slice, not a single object. If you check the error on unmarshal, you will see that.

Last, there is a problem with the CreationDate field. Unmarshal error shows that too.

package main

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "os"
    "text/template"
)

type Response struct {
    Artists   string `json:"artists"`
    Locations string `json:"locations"`
    Dates     string `json:"dates"`
    Relation  string `json:"relation"`
}
type Artist struct {
    ID           int      `json:"id"`
    Image        string   `json:"image"`
    Name         string   `json:"name"`
    Members      []string `json:"members"`
    CreationDate int      `json:"creationDate"`
    FirstAlbum   string   `json:"firstAlbum"`
}

var temp *template.Template

func main() {
    temp = template.Must(template.ParseFiles("index.html"))

    http.HandleFunc("/", formHandler) // to define the path/page, where we are going to use the mentioned function
    fmt.Printf("Starting server at port 8080\n")
    if err := http.ListenAndServe(":8080", nil); err != nil { //to initialise our server on :8080
        log.Fatal("HTTP status 500 - Internal server error: %s", err)
    }
}
func formHandler(w http.ResponseWriter, r *http.Request) {
    response, err := http.Get("https://groupietrackers.herokuapp.com/api")
    if err != nil {
        fmt.Print(err.Error())
        os.Exit(1)
    }

    responseData, err := ioutil.ReadAll(response.Body)
    if err != nil {
        log.Fatal(err)
    }

    var responseObject Response

    json.Unmarshal(responseData, &responseObject)
    artist_link, err := http.Get(responseObject.Artists)
    if err != nil {
        fmt.Print(err.Error())
        os.Exit(1)
    }

    artistData, err := ioutil.ReadAll(artist_link.Body)
    if err != nil {
        log.Fatal(err)
    }

    var artists []Artist

    err = json.Unmarshal(artistData, &artists)
    if err != nil {
        log.Fatal(err)
    }

    temp.Execute(w, artists)
}