diff --git a/cmd/ppf/main.go b/cmd/ppf/main.go
index 776b5a8..244e85c 100644
--- a/cmd/ppf/main.go
+++ b/cmd/ppf/main.go
@@ -1,9 +1,9 @@
 package main
 
 import (
-	"gitea.mmo.to/ProtocolPacketForger/ppf"
+	"gitea.mmo.to/ProtocolPacketForger/ppf/internal/app"
 )
 
 func main() {
-	ppf.Appmain()
+	app.Appmain()
 }
diff --git a/controller.go b/controller.go
deleted file mode 100644
index 218ff97..0000000
--- a/controller.go
+++ /dev/null
@@ -1,53 +0,0 @@
-package ppf
-
-func NewDataModel(name string) *DataModel {
-	return &DataModel{
-		Name: name,
-	}
-}
-
-func (dm *DataModel) AddProtocol(name string) {
-
-}
-
-func (dm *DataModel) RemoveProtocolByName(name string) {
-
-}
-
-func (dm *DataModel) RemoveProtocolElement(id uint) {
-
-}
-
-func (dm *DataModel) NewProtocol(name string) {
-
-}
-
-func (dm *DataModel) SaveNewProtocol(editorContent ProtocolEditor) {
-
-}
-
-func (dm *DataModel) GetPacketEditor() *PacketEditor {
-
-	return nil
-}
-
-func (dm *DataModel) SwitchToProtocolEditor() {
-
-}
-
-func (dm *DataModel) SyncPacketEditor(pkgedt *PacketEditor) {
-
-}
-
-func (dm *DataModel) GetPackageBytes() []byte {
-
-	return []byte{}
-}
-
-func (dm *DataModel) FromSaved(path string) {
-
-}
-
-func (dm *DataModel) SaveAsPcap(path string) {
-
-}
diff --git a/app.go b/internal/app/app.go
similarity index 94%
rename from app.go
rename to internal/app/app.go
index 35e05c0..e0a6e63 100644
--- a/app.go
+++ b/internal/app/app.go
@@ -1,4 +1,4 @@
-package ppf
+package app
 
 import (
 	"fyne.io/fyne/v2"
@@ -7,6 +7,8 @@ import (
 	"fyne.io/fyne/v2/layout"
 	"fyne.io/fyne/v2/theme"
 	"fyne.io/fyne/v2/widget"
+
+	"gitea.mmo.to/ProtocolPacketForger/ppf/internal/ui"
 )
 
 var fyneApp fyne.App
@@ -35,8 +37,8 @@ type ppfApp struct {
 	Settings        map[string]string
 	ProtocolForging bool
 	// Once initialized instances of the editor views
-	EditorPacket   *PacketEditor
-	EditorProtocol *ProtocolEditor
+	EditorPacket   *ui.PacketEditor
+	EditorProtocol *ui.ProtocolEditor
 }
 
 var ppf ppfApp
@@ -85,7 +87,7 @@ func CreateToolbar() fyne.CanvasObject {
 }
 
 func CreateWorkarea() *fyne.Container {
-	return GetProtocolEditor().Representation
+	return ui.GetProtocolEditor().Representation
 }
 
 func CreateMetadataProtocol() *fyne.Container {
diff --git a/fieldadd.go b/internal/ui/fieldadd.go
similarity index 95%
rename from fieldadd.go
rename to internal/ui/fieldadd.go
index f515cff..b24bb80 100644
--- a/fieldadd.go
+++ b/internal/ui/fieldadd.go
@@ -1,4 +1,4 @@
-package ppf
+package ui
 
 import (
 	"fyne.io/fyne/v2/widget"
diff --git a/fieldcreator.go b/internal/ui/fieldcreator.go
similarity index 99%
rename from fieldcreator.go
rename to internal/ui/fieldcreator.go
index 7cc4554..b8add78 100644
--- a/fieldcreator.go
+++ b/internal/ui/fieldcreator.go
@@ -1,4 +1,4 @@
-package ppf
+package ui
 
 import (
 	"fyne.io/fyne/v2"
diff --git a/fieldview.go b/internal/ui/fieldview.go
similarity index 93%
rename from fieldview.go
rename to internal/ui/fieldview.go
index ca0f5b2..6fd0b98 100644
--- a/fieldview.go
+++ b/internal/ui/fieldview.go
@@ -1,4 +1,4 @@
-package ppf
+package ui
 
 import (
 	"fyne.io/fyne/v2/widget"
diff --git a/flowlayout.go b/internal/ui/flowlayout.go
similarity index 99%
rename from flowlayout.go
rename to internal/ui/flowlayout.go
index d1cef17..51fd75a 100644
--- a/flowlayout.go
+++ b/internal/ui/flowlayout.go
@@ -1,4 +1,4 @@
-package ppf
+package ui
 
 import (
 	"fyne.io/fyne/v2"
diff --git a/packeteditor.go b/internal/ui/packeteditor.go
similarity index 88%
rename from packeteditor.go
rename to internal/ui/packeteditor.go
index 433c20c..206adc3 100644
--- a/packeteditor.go
+++ b/internal/ui/packeteditor.go
@@ -1,4 +1,4 @@
-package ppf
+package ui
 
 import "fyne.io/fyne/v2"
 
diff --git a/protocoleditor.go b/internal/ui/protocoleditor.go
similarity index 98%
rename from protocoleditor.go
rename to internal/ui/protocoleditor.go
index edc3bab..5add203 100644
--- a/protocoleditor.go
+++ b/internal/ui/protocoleditor.go
@@ -1,4 +1,4 @@
-package ppf
+package ui
 
 import (
 	"fyne.io/fyne/v2"
diff --git a/packet/fieldvalue.go b/packet/fieldvalue.go
index e69de29..9c40969 100644
--- a/packet/fieldvalue.go
+++ b/packet/fieldvalue.go
@@ -0,0 +1 @@
+package packet
diff --git a/packet/packet.go b/packet/packet.go
index e69de29..9c40969 100644
--- a/packet/packet.go
+++ b/packet/packet.go
@@ -0,0 +1 @@
+package packet
diff --git a/packetctl/packetctl.go b/packetctl/packetctl.go
index e69de29..53325c8 100644
--- a/packetctl/packetctl.go
+++ b/packetctl/packetctl.go
@@ -0,0 +1 @@
+package packetctl
diff --git a/protocol/field.go b/protocol/field.go
index 75e1714..70efb1d 100644
--- a/protocol/field.go
+++ b/protocol/field.go
@@ -1,5 +1,7 @@
 package protocol
 
+import "encoding/json"
+
 type Field struct {
 	Name      string  // Name of the Field
 	Desc      string  // Lengthy description
@@ -9,3 +11,11 @@ type Field struct {
 	Optional  bool    // Is this field required?
 	Payload   bool    // Is this field the payload or next protocol level?
 }
+
+func (f *Field) ToJson() string {
+	b, err := json.Marshal(*f)
+	if err != nil {
+		return ""
+	}
+	return string(b)
+}
diff --git a/protocolctl/protocolctl.go b/protocolctl/protocolctl.go
index 6135a84..ed966f3 100644
--- a/protocolctl/protocolctl.go
+++ b/protocolctl/protocolctl.go
@@ -59,36 +59,26 @@ func AppendField(prot *protocol.ProtocolStructure, field *protocol.Field) {
 	prot.Structure = append(prot.Structure, *field)
 }
 
-func UpdateFieldByRef(prot *protocol.ProtocolStructure, field *protocol.Field) {
-	for _, f := range prot.Structure {
-		if f.Name == field.Name {
-			f.Desc = field.Desc
-			f.Optional = field.Optional
-			f.Payload = field.Payload
-			f.Regex = field.Regex
-			f.Size = field.Size
-			f.SubFields = field.SubFields
+func UpdateFieldByName(prot *protocol.ProtocolStructure, name string, field *protocol.Field) {
+	var fnd int = -1
+	for i, f := range prot.Structure {
+		if f.Name == name {
+			fnd = i
 		}
 	}
+	if fnd != -1 {
+		prot.Structure[fnd] = *field
+	}
 }
 
 func UpdateFieldByElement(prot *protocol.ProtocolStructure, element int, field *protocol.Field) {
-	for i, f := range prot.Structure {
-		if i == element {
-			f.Desc = field.Desc
-			f.Optional = field.Optional
-			f.Payload = field.Payload
-			f.Regex = field.Regex
-			f.Size = field.Size
-			f.SubFields = field.SubFields
-		}
-	}
+	prot.Structure[element] = *field
 }
 
-func RemoveFieldByRef(prot *protocol.ProtocolStructure, field *protocol.Field) {
+func RemoveFieldByName(prot *protocol.ProtocolStructure, name string) {
 	element := -1
 	for i, f := range prot.Structure {
-		if f.Name == field.Name {
+		if f.Name == name {
 			element = i
 		}
 	}
@@ -120,6 +110,14 @@ func LoadNew(path string) (*protocol.ProtocolStructure, error) {
 	return prot, err
 }
 
+func ToJson(prot *protocol.ProtocolStructure) string {
+	data, err := json.Marshal(*prot)
+	if err != nil {
+		return ""
+	}
+	return string(data)
+}
+
 func Save(prot *protocol.ProtocolStructure, path string) error {
 	data, err := json.Marshal(*prot)
 	if err != nil {
diff --git a/protocolctl/protocolctl_test.go b/protocolctl/protocolctl_test.go
new file mode 100644
index 0000000..4a14788
--- /dev/null
+++ b/protocolctl/protocolctl_test.go
@@ -0,0 +1,144 @@
+package protocolctl
+
+import (
+	"fmt"
+	"testing"
+
+	"gitea.mmo.to/ProtocolPacketForger/ppf/protocol"
+)
+
+func TestUpdateMetaData(t *testing.T) {
+	var (
+		name        string = "test"
+		version     string = "1.0.0"
+		osilayer    uint   = 3
+		tcpiplayer  uint   = 2
+		extensionTo string = ""
+		desc        string = "description"
+	)
+	prot := NewProtocolStructure()
+	UpdateMetaData(
+		prot,
+		name,
+		version,
+		tcpiplayer,
+		osilayer,
+		extensionTo,
+		desc,
+		nil,
+		nil,
+	)
+
+	if prot.Metadata.Name != name ||
+		prot.Metadata.Description != desc ||
+		prot.Metadata.ExtensionTo != extensionTo ||
+		prot.Metadata.OSILayer != osilayer ||
+		prot.Metadata.TCPIPLayer != tcpiplayer ||
+		prot.Metadata.Version != version ||
+		prot.Metadata.LowerLayerIdentification != nil ||
+		prot.Metadata.RequiredJSFunctions != nil {
+		t.Log("Data hasn't been set correctly!")
+		t.Fail()
+	}
+}
+
+func GenerateFields() []protocol.Field {
+	slc := make([]protocol.Field, 0)
+	for i := 0; i < 10; i++ {
+		slc = append(slc, *NewField(
+			fmt.Sprintf("testfield%d", i),
+			fmt.Sprintf("Description %d", i),
+			"",
+			uint(i*8),
+			nil,
+			false,
+			false,
+		))
+	}
+	return slc
+}
+
+func GenerateStructure() *protocol.ProtocolStructure {
+	p := NewProtocolStructure()
+	slc := GenerateFields()
+	for i, e := range slc {
+		AppendField(p, &e)
+		fmt.Printf("%d %s\n", i, e.ToJson())
+	}
+	return p
+}
+
+func TestFieldAppend(t *testing.T) {
+	f := NewField(
+		"testfield",
+		"Description",
+		"",
+		8,
+		nil,
+		false,
+		false,
+	)
+	p := NewProtocolStructure()
+	AppendField(p, f)
+	if p.Structure[0].Name != "testfield" {
+		t.Log("Append failed.")
+		t.Fail()
+	}
+}
+
+func TestUpdateFieldByName(t *testing.T) {
+	p := GenerateStructure()
+	f := NewField(
+		"UpdatedField", "", "", 42, nil, false, true,
+	)
+	UpdateFieldByName(p, "testfield3", f)
+	for i, e := range p.Structure {
+		fmt.Printf("%d %s\n", i, e.ToJson())
+	}
+	if p.Structure[3].Desc != "" || p.Structure[3].Size != 42 {
+		t.Log("Update field by Ref failed!")
+		t.Fail()
+	}
+}
+func TestUpdateFieldByElement(t *testing.T) {
+	p := GenerateStructure()
+	f := NewField(
+		"UpdatedField", "", "", 42, nil, false, true,
+	)
+	UpdateFieldByElement(p, 5, f)
+	for i, e := range p.Structure {
+		fmt.Printf("%d %s\n", i, e.ToJson())
+	}
+	if p.Structure[5].Desc != "" || p.Structure[5].Size != 42 {
+		t.Log("Update field by Ref failed!")
+		t.Fail()
+	}
+}
+
+func TestRemoveFieldByName(t *testing.T) {
+	p := GenerateStructure()
+	RemoveFieldByName(p, "testfield3")
+	for i, e := range p.Structure {
+		fmt.Printf("%d %s\n", i, e.ToJson())
+	}
+	if p.Structure[3].Name != "testfield4" {
+		t.Log("Remove by name failed!")
+		t.Fail()
+	}
+}
+func TestRemoveFieldByElement(t *testing.T) {
+	p := GenerateStructure()
+	RemoveFieldByElement(p, 3)
+	for i, e := range p.Structure {
+		fmt.Printf("%d %s\n", i, e.ToJson())
+	}
+	if p.Structure[3].Name != "testfield4" {
+		t.Log("Remove by name failed!")
+		t.Fail()
+	}
+}
+
+func TestToJson(t *testing.T) {
+	p := GenerateStructure()
+	fmt.Print(ToJson(p))
+}