Question

This似乎可能会回答我的问题，但是我无法将输出写入/保存到＆＃34; somefile.json＆＃34; （在我的代码中命名为＆＃34; deck.json＆＃34;无论我尝试过什么）。我的猜测是由于文件在错误的时间打开/关闭，表单输入和编写器相互缺失，但老实说我不知道。我试图将这个示例变成一个允许用户输入将保存到JSON文件的术语和定义的表单，该文件将由JavaScript驱动的闪存卡＆＃34;应用程序安装在另一页上。

这是我现在的代码：

HTML：

<html>
<head>
        <meta charset="utf-8">
        <title>Flashcards for Learning JS</title>
</head>
<body>
   <br>
<form action="/addcard" method="post">
   <input type="text" name="term" placeholder="Term">
   <br>
   <br>
   <input type="text" name="definition" placeholder="Definition">
   <br>
   <br>
   <input type="submit" value="Add Card">
</form>
</body>
</html>

GO：

 package main

import (
    "encoding/json"
    "html/template"
    "net/http"
    "os"
)

type Card struct {
    Term       string `json:"term"`
    Definition string `json:"definition"`
}

func open(w http.ResponseWriter, r *http.Request) {
    t, _ := template.ParseFiles("Form.html")
    t.Execute(w, nil)
}

func addcard(w http.ResponseWriter, r *http.Request) {
    f, err := os.Open("deck.json")
    if err != nil {
        http.Error(w, err.Error(), 500)
        return
    }

    card := new(Card)
    card.Term = r.FormValue("term")
    card.Definition = r.FormValue("definition")

    b, err := json.Marshal(card)
    if err != nil {
        http.Error(w, err.Error(), 500)
        return
    }

    f.Write(b)
    f.Close()
}

func main() {
    http.HandleFunc("/", open)
    http.ListenAndServe(":8080", nil)
    http.HandleFunc("/addcard", addcard)
}

Answer 1

Changed per recommendations made by @JimB. Fixed handler order, and program successfully concatenates each successive submission as valid JSON to the file in question.

HTML:

<html>
<head>
        <meta charset="utf-8">
        <title>Flashcards for Learning JS</title>
</head>
<body>
   <br>
<form action="/addcard" method="post">
   <input type="text" name="term" placeholder="Term">
   <br>
   <br>
   <input type="text" name="definition" placeholder="Definition">
   <br>
   <br>
   <input type="submit" value="Add Card">
</form>
</body>
</html>

GO:

package main

import (
    "encoding/json"
    "html/template"
    "net/http"
    "os"
)

type Card struct { //defining the data structure for our virtual flashcards
    Term       string `json:"Term"`
    Definition string `json:"Definition"`
}

func open(w http.ResponseWriter, r *http.Request) {
    t, _ := template.ParseFiles("addcard.html")
    t.Execute(w, nil)
}

func addcard(w http.ResponseWriter, r *http.Request) {
    f, err := os.OpenFile("deck.json", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
    if err != nil {
        http.Error(w, err.Error(), 500)
        return
    }
    defer f.Close()

    card := new(Card)
    card.Term = r.FormValue("term")
    card.Definition = r.FormValue("definition")

    b, err := json.Marshal(card)
    if err != nil {
        http.Error(w, err.Error(), 500)
        return
    }

    f.Write(b)
    f.Close()
}

func main() {
    http.HandleFunc("/addcard", addcard)
    http.HandleFunc("/", open)
    http.ListenAndServe(":8080", nil)

}

编组HTML表单输入到JSON并写入文件，golang

1 个答案: