From 7fc73f1e93efd6b559467fff3a5e7de86c4fba34 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mike=20Schw=C3=B6rer?= <pubgit@mikescher.com>
Date: Tue, 11 Jun 2024 19:34:48 +0200
Subject: [PATCH] v0.0.470 Add GoextJsonMarshaller interface to call when
 marshalling json via gojson

---
 goextVersion.go           |  4 ++--
 gojson/encode.go          |  7 +++++++
 gojson/interfaces.go      | 13 +++++++++++++
 gojson/interfaces_test.go | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 59 insertions(+), 2 deletions(-)
 create mode 100644 gojson/interfaces.go
 create mode 100644 gojson/interfaces_test.go

diff --git a/goextVersion.go b/goextVersion.go
index b714638..7d6ec88 100644
--- a/goextVersion.go
+++ b/goextVersion.go
@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.469"
+const GoextVersion = "0.0.470"
 
-const GoextVersionTimestamp = "2024-06-11T12:10:49+0200"
+const GoextVersionTimestamp = "2024-06-11T19:34:48+0200"
diff --git a/gojson/encode.go b/gojson/encode.go
index aca278f..903c03b 100644
--- a/gojson/encode.go
+++ b/gojson/encode.go
@@ -769,6 +769,13 @@ type structFields struct {
 }
 
 func (se structEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
+
+	if v.CanAddr() && v.Addr().Type().Implements(goextJsonMarshallerType) {
+		if gejm, ok := v.Addr().Interface().(GoextJsonMarshaller); ok {
+			gejm.PreGoJsonMarshal()
+		}
+	}
+
 	next := byte('{')
 FieldLoop:
 	for i := range se.fields.list {
diff --git a/gojson/interfaces.go b/gojson/interfaces.go
new file mode 100644
index 0000000..5f0fe02
--- /dev/null
+++ b/gojson/interfaces.go
@@ -0,0 +1,13 @@
+package json
+
+import (
+	"reflect"
+)
+
+type GoextJsonMarshaller interface {
+	PreGoJsonMarshal()
+}
+
+var (
+	goextJsonMarshallerType = reflect.TypeOf((*GoextJsonMarshaller)(nil)).Elem()
+)
diff --git a/gojson/interfaces_test.go b/gojson/interfaces_test.go
new file mode 100644
index 0000000..502afbe
--- /dev/null
+++ b/gojson/interfaces_test.go
@@ -0,0 +1,37 @@
+package json
+
+import (
+	"fmt"
+	"testing"
+)
+
+type testStruct1 struct {
+	TS2 *testStruct2 `json:"ts2"`
+}
+
+type testStruct2 struct {
+	A string `json:"a"`
+}
+
+func (t *testStruct2) PreGoJsonMarshal() {
+	t.A = "Hello"
+}
+
+func TestGoextJsonMarshaller(t *testing.T) {
+	t1 := testStruct1{TS2: &testStruct2{}}
+
+	v, err := Marshal(t1)
+	if err != nil {
+		t.Fatal()
+	}
+
+	fmt.Printf("%s\n", v)
+
+	if string(v) != `{"ts2":{"a":"Hello"}}` {
+		t.Fatalf("PreGoJsonMarshal failed")
+	}
+
+	if t1.TS2.A != "Hello" {
+		t.Fatalf("PreGoJsonMarshal failed")
+	}
+}