🔥 Add function to override form decoder setting (#1100)

* 🔥 add function to overide form decoder setting

🔥 Feature : SetBodyParserDecoder map all option to form decoder, use with BodyParserConfig, BodyParserType

🚨 Test : Test_Ctx_BodyParser_WithSetBodyParserDecoder

* 🔥 Use decoder builder function with default setting on init decoderPool

ctx.go

@@ -86,6 +86,21 @@ type Views interface {
 	Render(io.Writer, string, interface{}, ...string) error
 }
 
+// BodyParserType require two element, type and converter for register.
+// Use BodyParserType with BodyParser for parsing custom type in form data.
+type BodyParserType struct {
+	Customtype interface{}
+	Converter  func(string) reflect.Value
+}
+
+// BodyParserConfig form decoder config for SetBodyParserDecoder
+type BodyParserConfig struct {
+	IgnoreUnknownKeys bool
+	SetAliasTag       string
+	BodyParserType    []BodyParserType
+	ZeroEmpty         bool
+}
+
 // AcquireCtx retrieves a new Ctx from the pool.
 func (app *App) AcquireCtx(fctx *fasthttp.RequestCtx) *Ctx {
 	c := app.pool.Get().(*Ctx)
@@ -272,12 +287,32 @@ func (c *Ctx) Body() []byte {
 
 // decoderPool helps to improve BodyParser's and QueryParser's performance
 var decoderPool = &sync.Pool{New: func() interface{} {
-	var decoder = schema.NewDecoder()
+	return decoderBuilder(BodyParserConfig{
-	decoder.ZeroEmpty(true)
+		IgnoreUnknownKeys: true,
-	decoder.IgnoreUnknownKeys(true)
+		ZeroEmpty:         true,
-	return decoder
+	})
 }}
 
+// SetBodyParserDecoder allow globally change the option of form decoder, update decoderPool
+func SetBodyParserDecoder(bodyParserConfig BodyParserConfig) {
+	decoderPool = &sync.Pool{New: func() interface{} {
+		return decoderBuilder(bodyParserConfig)
+	}}
+}
+
+func decoderBuilder(bodyParserConfig BodyParserConfig) interface{} {
+	var decoder = schema.NewDecoder()
+	decoder.IgnoreUnknownKeys(bodyParserConfig.IgnoreUnknownKeys)
+	if bodyParserConfig.SetAliasTag != "" {
+		decoder.SetAliasTag(bodyParserConfig.SetAliasTag)
+	}
+	for _, v := range bodyParserConfig.BodyParserType {
+		decoder.RegisterConverter(reflect.ValueOf(v.Customtype).Interface(), v.Converter)
+	}
+	decoder.ZeroEmpty(bodyParserConfig.ZeroEmpty)
+	return decoder
+}
+
 // BodyParser binds the request body to a struct.
 // It supports decoding the following content types based on the Content-Type header:
 // application/json, application/xml, application/x-www-form-urlencoded, multipart/form-data

ctx_test.go

@@ -399,6 +399,60 @@ func Test_Ctx_BodyParser(t *testing.T) {
 	testDecodeParserError(MIMEMultipartForm+`;boundary="b"`, "--b")
 }
 
+// go test -run Test_Ctx_BodyParser_WithSetBodyParserDecoder
+func Test_Ctx_BodyParser_WithSetBodyParserDecoder(t *testing.T) {
+	type CustomTime time.Time
+
+	var timeConverter = func(value string) reflect.Value {
+		if v, err := time.Parse("2006-01-02", value); err == nil {
+			return reflect.ValueOf(v)
+		}
+		return reflect.Value{}
+	}
+
+	customTime := BodyParserType{
+		Customtype: CustomTime{},
+		Converter:  timeConverter,
+	}
+
+	SetBodyParserDecoder(BodyParserConfig{
+		IgnoreUnknownKeys: true,
+		BodyParserType:    []BodyParserType{customTime},
+		ZeroEmpty:         true,
+		SetAliasTag:       "form",
+	})
+
+	t.Parallel()
+	app := New()
+	c := app.AcquireCtx(&fasthttp.RequestCtx{})
+	defer app.ReleaseCtx(c)
+
+	type Demo struct {
+		Date  CustomTime `form:"date"`
+		Title string     `form:"title"`
+		Body  string     `form:"body"`
+	}
+
+	testDecodeParser := func(contentType, body string) {
+		c.Request().Header.SetContentType(contentType)
+		c.Request().SetBody([]byte(body))
+		c.Request().Header.SetContentLength(len(body))
+		d := Demo{
+			Title: "Existing title",
+			Body:  "Existing Body",
+		}
+		utils.AssertEqual(t, nil, c.BodyParser(&d))
+		date := fmt.Sprintf("%v", d.Date)
+		fmt.Println(date, d.Title, d.Body)
+		utils.AssertEqual(t, "{0 63743587200 <nil>}", date)
+		utils.AssertEqual(t, "", d.Title)
+		utils.AssertEqual(t, "New Body", d.Body)
+	}
+
+	testDecodeParser(MIMEApplicationForm, "date=2020-12-15&title=&body=New Body")
+	testDecodeParser(MIMEMultipartForm+`; boundary="b"`, "--b\r\nContent-Disposition: form-data; name=\"date\"\r\n\r\n2020-12-15\r\n--b\r\nContent-Disposition: form-data; name=\"title\"\r\n\r\n\r\n--b\r\nContent-Disposition: form-data; name=\"body\"\r\n\r\nNew Body\r\n--b--")
+}
+
 // go test -v -run=^$ -bench=Benchmark_Ctx_BodyParser_JSON -benchmem -count=4
 func Benchmark_Ctx_BodyParser_JSON(b *testing.B) {
 	app := New()