Content-Type: "application/json"
The Context.JSON(v, ...opts)
is the method which sends JSON responses to the client. It accepts the value and optional settings for rendering. The JSON
options structure looks like this:
// JSON contains the options for the JSON (Context's) Renderer.type JSON struct {// http-specificStreamingJSON bool// content-specificUnescapeHTML boolIndent stringPrefix stringASCII bool// if true then it prepends a "while(1);" when Go slice (to JSON Array) value.Secure bool// proto.Message specific marshal options.Proto ProtoMarshalOptions}
If
Indent
field is empty and the application runs without optimizations, theIndent
field will be automatically set to2 spaces
.
So, if we want to write a JSON with indentation of four spaces and prefixed with while(1)
we can do something like that:
func handler(ctx iris.Context) {response := []string{"val1", "val2", "val3"}options := iris.JSON{Indent: " ", Secure: true}ctx.JSON(response, options)}
Result
while(1);["val1","val2","val3"]
As with all RESTful rich responses, any marshallable (JSON at this case) Go type can be given. If we want to render a Go struct as JSON, the struct's fields we want to render should be exported, and optionally tagged with the json
struct tag. Look the exaple below:
type User struct {Firstname string `json:"firstname"`Lastname string `json:"lastname"`IgnoredField int `json:"-"`}func handler(ctx iris.Context) {response := User{Firstname: "makis",Lastname: "maropoulos",IgnoredField:42,}ctx.JSON(response)}
Result
{"firstname": "makis","lastname": "maropoulos"}
Use the ASCII
field to generate ASCII-only JSON with escaped non-ASCII characters.
app.Get("/json_ascii", func(ctx iris.Context) {response := iris.Map{"lang": "GO-虹膜", "tag": "<br>"}options := iris.JSON{Indent: " ", ASCII: true}ctx.JSON(response, options)})
Result
{"lang": "GO-\u8679\u819c","tag": "\u003cbr\u003e"}
Do not replace special HTML characters with their unicode entities using the UnescapeHTML
field.
app.Get("/json_raw", func(ctx iris.Context) {options := iris.JSON{UnescapeHTML: true}ctx.JSON(iris.Map{"html": "<b>Hello, world!</b>",}, options)})
Result
{"html":"<b>Hello, world!</b>"}