From edc1f785302dc893242ce864cc64020cddd2cdb7 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Fri, 11 Sep 2015 07:35:57 +0800
Subject: [PATCH] Fix calculate fields for the first time

---
 field_test.go   | 34 ++++++++++++++++++++++++++++++++++
 model_struct.go |  8 ++++++--
 2 files changed, 40 insertions(+), 2 deletions(-)
 create mode 100644 field_test.go

diff --git a/field_test.go b/field_test.go
new file mode 100644
index 00000000..d19b3b1b
--- /dev/null
+++ b/field_test.go
@@ -0,0 +1,34 @@
+package gorm_test
+
+import (
+	"testing"
+
+	"github.com/jinzhu/gorm"
+)
+
+type CalculateField struct {
+	gorm.Model
+	Name     string
+	Children []CalculateFieldChild
+	Category CalculateFieldCategory
+}
+
+type CalculateFieldChild struct {
+	gorm.Model
+	CalculateFieldID uint
+	Name             string
+}
+
+type CalculateFieldCategory struct {
+	gorm.Model
+	CalculateFieldID uint
+	Name             string
+}
+
+func TestCalculateField(t *testing.T) {
+	var field CalculateField
+	fields := DB.NewScope(&field).Fields()
+	if fields["children"].Relationship == nil || fields["category"].Relationship == nil {
+		t.Errorf("Should calculate fields correctly for the first time")
+	}
+}
diff --git a/model_struct.go b/model_struct.go
index f6e035f8..608c70d4 100644
--- a/model_struct.go
+++ b/model_struct.go
@@ -153,7 +153,8 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 		}
 	}
 
-	defer func() {
+	var finished = make(chan bool)
+	go func(finished chan bool) {
 		for _, field := range fields {
 			if !field.IsIgnored {
 				fieldStruct := field.Struct
@@ -365,10 +366,13 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 			}
 			modelStruct.StructFields = append(modelStruct.StructFields, field)
 		}
-	}()
+		finished <- true
+	}(finished)
 
 	modelStructs[scopeType] = &modelStruct
 
+	<-finished
+
 	return &modelStruct
 }