How to Stop Go\'s JSON Marshaler from Converting \'&\' to \'&\'?

How to Prevent JSON from Converting '&' to '&'?

Problem Scenario

Consider the following code snippet:

package main</p>
<p>import (</p>
<div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false">"encoding/json"
"fmt"
"log"
"net/http"

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)

func testFunc(w http.ResponseWriter, r *http.Request) {

data := make(map[string]string)
data["key"] = "&"
bytes, err := json.Marshal(data)
if err != nil {
    fmt.Fprintln(w, "generator json error")
} else {
    //print console
    fmt.Println(string(bytes))
    fmt.Println("&")
    //print broswer
    fmt.Fprintln(w, string(bytes))
    fmt.Fprintln(w, "&")
}

}

func main() {

http.HandleFunc("/", testFunc)
err := http.ListenAndServe(":9090", nil)
if err != nil {
    log.Fatal("ListenAndServe", err)
}

}

Upon executing this code, we notice that the ampersand character ('&') is being converted to & in both the browser and console output, despite its intended display as '&'.

Solution

In Go 1.7, a new option was introduced to address this issue:

func (*Encoder) SetEscapeHTML

This function allows us to disable the escaping of HTML entities, including '&', '<', and '>'.

To implement this solution in the example code, we modify the testFunc function as follows:

func testFunc(w http.ResponseWriter, r *http.Request) {</p>
<div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false">...

enc := json.NewEncoder(w)
enc.SetEscapeHTML(false)

...

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