I am learning Go by building a simple API interface for a web server. I want to return a simple message in JSON, when a default route is hit.
So far, reading online, this is the easiest way to return a literal JSON string, and encode it and send it to the user.
func GetDefault(c *gin.Context) {
jsonData := []byte(`{"msg":"this worked"}`)
var v interface{}
json.Unmarshal(jsonData, &v)
data := v.(map[string]interface{})
c.JSON(http.StatusOK,data)
}
Is this the most efficient / fastest way to do it?
in node.js and express, I would do something like:
return res.status(200).json({"msg":"this worked"});
Whats the best way to do this in Go + Gin?
you can use the gin.H
struct on you response:
c.JSON(http.StatusOK, gin.H{"msg":"this worked"})
One option is to use Context.Data()
where you provide the data to send (along with the content type):
func GetDefault(c *gin.Context) {
jsonData := []byte(`{"msg":"this worked"}`)
c.Data(http.StatusOK, "application/json", jsonData)
}
You may also use a constant for the content type:
func GetDefault(c *gin.Context) {
jsonData := []byte(`{"msg":"this worked"}`)
c.Data(http.StatusOK, gin.MIMEJSON, jsonData)
}
If your data is availabe as a string
value and is big, you can avoid converting it to []byte
if you use Context.DataFromReader()
:
func GetDefault(c *gin.Context) {
jsonStr := `{"msg":"this worked"}`
c.DataFromReader(http.StatusOK,
int64(len(jsonStr)), gin.MIMEJSON, strings.NewReader(jsonStr), nil)
}
This solution also works if you have your JSON as an io.Reader
, e.g. an os.File
.