[configYaml] Fall back to default values if the file exists, but is empty

Quick.Config.YAML.pas

@@ -1,298 +1,302 @@
-{ ***************************************************************************
-
-  Copyright (c) 2015-2019 Kike Pérez
-
-  Unit        : Quick.Config.YAML
-  Description : Save config to YAML file
-  Author      : Kike Pérez
-  Version     : 1.0
-  Created     : 12/04/2019
-  Modified    : 27/04/2019
-
-  This file is part of QuickLib: https://github.com/exilon/QuickLib
-
- ***************************************************************************
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-  http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
- *************************************************************************** }
-
-unit Quick.Config.YAML;
-
-{$i QuickLib.inc}
-
-interface
-
-uses
-  Classes,
-  SysUtils,
-  {$IFDEF DELPHIXE_UP}
-  IOUtils,
-  {$ELSE}
-  Quick.Files,
-  {$ENDIF}
-  Rtti,
-  Quick.YAML.Serializer,
-  Quick.FileMonitor,
-  Quick.Config.Base;
-
-type
-
-  TFileModifiedEvent = procedure of object;
-  TLoadConfigEvent = procedure of object;
-
-  {$IFNDEF FPC}
-  TNotSerializableProperty = Quick.YAML.Serializer.TNotSerializableProperty;
-  TCommentProperty = Quick.YAML.Serializer.TCommentProperty;
-  TCustomNameProperty = Quick.YAML.Serializer.TCustomNameProperty;
-  {$ENDIF}
-
-  TAppConfigYMALProvider = class(TAppConfigProvider)
-  private
-    fFilename : string;
-    fFileMonitor : TFileMonitor;
-    fOnFileModified : TFileModifiedEvent;
-    fLoaded : Boolean;
-    fReloadIfFileChanged : Boolean;
-    fOnConfigLoaded : TLoadConfigEvent;
-    fOnConfigReloaded : TLoadConfigEvent;
-    fNotifyReload : TLoadConfigEvent;
-    procedure CreateFileMonitor;
-    procedure FileModifiedNotify(MonitorNotify : TMonitorNotify);
-    procedure SetFileName(const Value: string);
-    procedure SetReloadIfFileChanged(const Value: Boolean);
-    procedure SetReloadNotify(aNotifyReload : TLoadConfigEvent);
-    procedure DoNofifyReload;
-  protected
-    procedure Load(cConfig : TAppConfig); override;
-    procedure Save(cConfig : TAppConfig); override;
-  public
-    constructor Create(const aFilename : string; aReloadIfFileChanged : Boolean = False); overload;
-    destructor Destroy; override;
-    property Filename : string read fFilename write SetFileName;
-    property ReloadIfFileChanged : Boolean read fReloadIfFileChanged write SetReloadIfFileChanged;
-    property IsLoaded : Boolean read fLoaded;
-    property OnFileModified : TFileModifiedEvent read fOnFileModified write fOnFileModified;
-    property OnConfigLoaded : TLoadConfigEvent read fOnConfigLoaded write fOnConfigLoaded;
-    property OnConfigReloaded : TLoadConfigEvent read fOnConfigReloaded write fOnConfigReloaded;
-  end;
-
-  TAppConfigYAML = class(TAppConfig)
-  private
-    function GetProvider : TAppConfigYMALProvider;
-    procedure ReloadNotify;
-  public
-    constructor Create(const aFilename : string; aReloadIfFileChanged : Boolean = False);
-    destructor Destroy; override;
-    property Provider : TAppConfigYMALProvider read GetProvider;
-    function ToYAML : string;
-    procedure FromYAML(const yaml : string);
-  end;
-
-  {Usage: create a descend class from TAppConfigYAML and add published properties to be loaded/saved
-
-  TMyConfig = class(TAppConfigYAML)
-  private
-    fName : string;
-    fSurname : string;
-    fStatus : Integer;
-  published
-    property Name : string read fName write fName;
-    property SurName : string read fSurname write fSurname;
-    property Status : Integer read fStatus write fStatus;
-  end;
-
-  MyConfig := TMyConfig.Create;
-  MyConfig.Provider.FileName := '.\MyAppName.yml';
-  MyConfig.Name := 'John';
-  MyConfig.Save;
-  }
-
-
-implementation
-
-constructor TAppConfigYMALProvider.Create(const aFilename : string; aReloadIfFileChanged : Boolean = False);
-begin
-  inherited Create;
-  if aFilename = '' then fFilename := TPath.ChangeExtension(ParamStr(0),'yml')
-    else fFilename := aFilename;
-  fLoaded := False;
-  fReloadIfFileChanged := aReloadIfFileChanged;
-  if aReloadIfFileChanged then CreateFileMonitor;
-end;
-
-procedure TAppConfigYMALProvider.CreateFileMonitor;
-begin
-  fFileMonitor := TQuickFileMonitor.Create;
-  fFileMonitor.FileName := fFilename;
-  fFileMonitor.Interval := 2000;
-  fFileMonitor.Notifies := [TMonitorNotify.mnFileModified];
-  fFileMonitor.OnFileChange := FileModifiedNotify;
-  fFileMonitor.Enabled := True;
-end;
-
-destructor TAppConfigYMALProvider.Destroy;
-begin
-  if Assigned(fFileMonitor) then fFileMonitor.Free;
-  inherited;
-end;
-
-procedure TAppConfigYMALProvider.DoNofifyReload;
-begin
-  if Assigned(fNotifyReload) then fNotifyReload
-    else raise EAppConfig.Create('Not config assigned to reload!');
-end;
-
-procedure TAppConfigYMALProvider.FileModifiedNotify(MonitorNotify : TMonitorNotify);
-begin
-  if MonitorNotify = TMonitorNotify.mnFileModified then
-  begin
-    if Assigned(fOnFileModified) then fOnFileModified;
-    if fReloadIfFileChanged then DoNofifyReload;
-  end;
-end;
-
-procedure TAppConfigYMALProvider.Load(cConfig : TAppConfig);
-var
-  yaml : TStrings;
-  serializer : TYamlSerializer;
-begin
-  if (not FileExists(fFilename)) and (CreateIfNotExists) then
-  begin
-    TAppConfig(cConfig).DefaultValues;
-    Self.Save(cConfig);
-  end;
-
-  try
-    yaml := TStringList.Create;
-    try
-      yaml.LoadFromFile(fFilename);
-      serializer := TYamlSerializer.Create(slPublishedProperty,UseEnumNames);
-      try
-        //Streamer.Options := Streamer.Options + [jsoDateTimeAsString ,jsoUseFormatString];
-        //Streamer.DateTimeFormat := 'yyyy-mm-dd"T"hh:mm:ss.zz';
-        serializer.YamlToObject(cConfig,yaml.Text);
-      finally
-        serializer.Free;
-      end;
-    finally
-      yaml.Free;
-    end;
-    if not fLoaded then
-    begin
-      fLoaded := True;
-      if Assigned(fOnConfigLoaded) then fOnConfigLoaded;
-    end
-    else if Assigned(fOnConfigReloaded) then fOnConfigReloaded;
-  except
-    on e : Exception do raise EAppConfig.Create(e.Message);
-  end;
-end;
-
-procedure TAppConfigYMALProvider.Save(cConfig : TAppConfig);
-var
-  yaml : TStrings;
-  Serializer : TYamlSerializer;
-begin
-  if not Assigned(cConfig) then cConfig := TAppConfigYAML.Create(fFilename,fReloadIfFileChanged);
-
-  try
-    yaml := TStringList.Create;
-    try
-      serializer := TYamlSerializer.Create(TSerializeLevel.slPublishedProperty,UseEnumNames);
-      try
-        //Streamer.Options := Streamer.Options + [jsoDateTimeAsString ,jsoUseFormatString];
-        //Streamer.DateTimeFormat := 'yyyy-mm-dd"T"hh:mm:ss.zz';
-        yaml.Text := serializer.ObjectToYaml(cConfig);
-      finally
-        serializer.Free;
-      end;
-      yaml.SaveToFile(fFilename);
-    finally
-      yaml.Free;
-    end;
-  except
-    on e : Exception do raise EAppConfig.Create(e.Message);
-  end;
-end;
-
-
-procedure TAppConfigYMALProvider.SetFileName(const Value: string);
-begin
-  fFilename := Value;
-  if Assigned(fFileMonitor) then fFileMonitor.Free;
-  if fReloadIfFileChanged then CreateFileMonitor;
-end;
-
-procedure TAppConfigYMALProvider.SetReloadIfFileChanged(const Value: Boolean);
-begin
-  if Value = fReloadIfFileChanged then Exit;
-  fReloadIfFileChanged := Value;
-  if Assigned(fFileMonitor) then fFileMonitor.Free;
-  if fReloadIfFileChanged then CreateFileMonitor;
-end;
-
-procedure TAppConfigYMALProvider.SetReloadNotify(aNotifyReload: TLoadConfigEvent);
-begin
-  fNotifyReload := aNotifyReload;
-end;
-
-{ TAppConfigYAML }
-
-constructor TAppConfigYAML.Create(const aFilename : string; aReloadIfFileChanged : Boolean = False);
-begin
-  inherited Create(TAppConfigYMALProvider.Create(aFileName,aReloadIfFileChanged));
-  TAppConfigYMALProvider(fProvider).SetReloadNotify(ReloadNotify);
-end;
-
-destructor TAppConfigYAML.Destroy;
-begin
-  inherited;
-end;
-
-function TAppConfigYAML.GetProvider: TAppConfigYMALProvider;
-begin
-  if not Assigned(fProvider) then raise EAppConfig.Create('No provider assigned!');
-  Result := TAppConfigYMALProvider(fProvider);
-end;
-
-procedure TAppConfigYAML.ReloadNotify;
-begin
-  Self.Load;
-end;
-
-function TAppConfigYAML.ToYAML: string;
-var
-  serializer : TYamlSerializer;
-begin
-  serializer := TYamlSerializer.Create(slPublishedProperty,fProvider.UseEnumNames);
-  try
-    Result := serializer.ObjectToYaml(Self);
-  finally
-    serializer.Free;
-  end;
-end;
-
-procedure TAppConfigYAML.FromYAML(const yaml: string);
-var
-  serializer : TYamlSerializer;
-begin
-  serializer := TYamlSerializer.Create(slPublishedProperty,fProvider.UseEnumNames);
-  try
-    serializer.YamlToObject(Self,yaml);
-  finally
-    serializer.Free;
-  end;
-end;
-
-end.
+{ ***************************************************************************
+
+  Copyright (c) 2015-2019 Kike Pérez
+
+  Unit        : Quick.Config.YAML
+  Description : Save config to YAML file
+  Author      : Kike Pérez
+  Version     : 1.0
+  Created     : 12/04/2019
+  Modified    : 27/04/2019
+
+  This file is part of QuickLib: https://github.com/exilon/QuickLib
+
+ ***************************************************************************
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+ *************************************************************************** }
+
+unit Quick.Config.YAML;
+
+{$i QuickLib.inc}
+
+interface
+
+uses
+  Classes,
+  SysUtils,
+  {$IFDEF DELPHIXE_UP}
+  IOUtils,
+  {$ELSE}
+  Quick.Files,
+  {$ENDIF}
+  Rtti,
+  Quick.YAML.Serializer,
+  Quick.FileMonitor,
+  Quick.Config.Base;
+
+type
+
+  TFileModifiedEvent = procedure of object;
+  TLoadConfigEvent = procedure of object;
+
+  {$IFNDEF FPC}
+  TNotSerializableProperty = Quick.YAML.Serializer.TNotSerializableProperty;
+  TCommentProperty = Quick.YAML.Serializer.TCommentProperty;
+  TCustomNameProperty = Quick.YAML.Serializer.TCustomNameProperty;
+  {$ENDIF}
+
+  TAppConfigYMALProvider = class(TAppConfigProvider)
+  private
+    fFilename : string;
+    fFileMonitor : TFileMonitor;
+    fOnFileModified : TFileModifiedEvent;
+    fLoaded : Boolean;
+    fReloadIfFileChanged : Boolean;
+    fOnConfigLoaded : TLoadConfigEvent;
+    fOnConfigReloaded : TLoadConfigEvent;
+    fNotifyReload : TLoadConfigEvent;
+    procedure CreateFileMonitor;
+    procedure FileModifiedNotify(MonitorNotify : TMonitorNotify);
+    procedure SetFileName(const Value: string);
+    procedure SetReloadIfFileChanged(const Value: Boolean);
+    procedure SetReloadNotify(aNotifyReload : TLoadConfigEvent);
+    procedure DoNofifyReload;
+  protected
+    procedure Load(cConfig : TAppConfig); override;
+    procedure Save(cConfig : TAppConfig); override;
+  public
+    constructor Create(const aFilename : string; aReloadIfFileChanged : Boolean = False); overload;
+    destructor Destroy; override;
+    property Filename : string read fFilename write SetFileName;
+    property ReloadIfFileChanged : Boolean read fReloadIfFileChanged write SetReloadIfFileChanged;
+    property IsLoaded : Boolean read fLoaded;
+    property OnFileModified : TFileModifiedEvent read fOnFileModified write fOnFileModified;
+    property OnConfigLoaded : TLoadConfigEvent read fOnConfigLoaded write fOnConfigLoaded;
+    property OnConfigReloaded : TLoadConfigEvent read fOnConfigReloaded write fOnConfigReloaded;
+  end;
+
+  TAppConfigYAML = class(TAppConfig)
+  private
+    function GetProvider : TAppConfigYMALProvider;
+    procedure ReloadNotify;
+  public
+    constructor Create(const aFilename : string; aReloadIfFileChanged : Boolean = False);
+    destructor Destroy; override;
+    property Provider : TAppConfigYMALProvider read GetProvider;
+    function ToYAML : string;
+    procedure FromYAML(const yaml : string);
+  end;
+
+  {Usage: create a descend class from TAppConfigYAML and add published properties to be loaded/saved
+
+  TMyConfig = class(TAppConfigYAML)
+  private
+    fName : string;
+    fSurname : string;
+    fStatus : Integer;
+  published
+    property Name : string read fName write fName;
+    property SurName : string read fSurname write fSurname;
+    property Status : Integer read fStatus write fStatus;
+  end;
+
+  MyConfig := TMyConfig.Create;
+  MyConfig.Provider.FileName := '.\MyAppName.yml';
+  MyConfig.Name := 'John';
+  MyConfig.Save;
+  }
+
+
+implementation
+
+constructor TAppConfigYMALProvider.Create(const aFilename : string; aReloadIfFileChanged : Boolean = False);
+begin
+  inherited Create;
+  if aFilename = '' then fFilename := TPath.ChangeExtension(ParamStr(0),'yml')
+    else fFilename := aFilename;
+  fLoaded := False;
+  fReloadIfFileChanged := aReloadIfFileChanged;
+  if aReloadIfFileChanged then CreateFileMonitor;
+end;
+
+procedure TAppConfigYMALProvider.CreateFileMonitor;
+begin
+  fFileMonitor := TQuickFileMonitor.Create;
+  fFileMonitor.FileName := fFilename;
+  fFileMonitor.Interval := 2000;
+  fFileMonitor.Notifies := [TMonitorNotify.mnFileModified];
+  fFileMonitor.OnFileChange := FileModifiedNotify;
+  fFileMonitor.Enabled := True;
+end;
+
+destructor TAppConfigYMALProvider.Destroy;
+begin
+  if Assigned(fFileMonitor) then fFileMonitor.Free;
+  inherited;
+end;
+
+procedure TAppConfigYMALProvider.DoNofifyReload;
+begin
+  if Assigned(fNotifyReload) then fNotifyReload
+    else raise EAppConfig.Create('Not config assigned to reload!');
+end;
+
+procedure TAppConfigYMALProvider.FileModifiedNotify(MonitorNotify : TMonitorNotify);
+begin
+  if MonitorNotify = TMonitorNotify.mnFileModified then
+  begin
+    if Assigned(fOnFileModified) then fOnFileModified;
+    if fReloadIfFileChanged then DoNofifyReload;
+  end;
+end;
+
+procedure TAppConfigYMALProvider.Load(cConfig : TAppConfig);
+var
+  yaml : TStrings;
+  serializer : TYamlSerializer;
+begin
+  if (not FileExists(fFilename)) and (CreateIfNotExists) then
+  begin
+    TAppConfig(cConfig).DefaultValues;
+    Self.Save(cConfig);
+  end;
+
+  try
+    yaml := TStringList.Create;
+    try
+      yaml.LoadFromFile(fFilename);
+      if yaml.Count > 0 then
+      begin
+        serializer := TYamlSerializer.Create(slPublishedProperty,UseEnumNames);
+        try
+          //Streamer.Options := Streamer.Options + [jsoDateTimeAsString ,jsoUseFormatString];
+          //Streamer.DateTimeFormat := 'yyyy-mm-dd"T"hh:mm:ss.zz';
+          serializer.YamlToObject(cConfig,yaml.Text);
+        finally
+          serializer.Free;
+        end;
+      end else
+        TAppConfig(cConfig).DefaultValues;
+    finally
+      yaml.Free;
+    end;
+    if not fLoaded then
+    begin
+      fLoaded := True;
+      if Assigned(fOnConfigLoaded) then fOnConfigLoaded;
+    end
+    else if Assigned(fOnConfigReloaded) then fOnConfigReloaded;
+  except
+    on e : Exception do raise EAppConfig.Create(e.Message);
+  end;
+end;
+
+procedure TAppConfigYMALProvider.Save(cConfig : TAppConfig);
+var
+  yaml : TStrings;
+  Serializer : TYamlSerializer;
+begin
+  if not Assigned(cConfig) then cConfig := TAppConfigYAML.Create(fFilename,fReloadIfFileChanged);
+
+  try
+    yaml := TStringList.Create;
+    try
+      serializer := TYamlSerializer.Create(TSerializeLevel.slPublishedProperty,UseEnumNames);
+      try
+        //Streamer.Options := Streamer.Options + [jsoDateTimeAsString ,jsoUseFormatString];
+        //Streamer.DateTimeFormat := 'yyyy-mm-dd"T"hh:mm:ss.zz';
+        yaml.Text := serializer.ObjectToYaml(cConfig);
+      finally
+        serializer.Free;
+      end;
+      yaml.SaveToFile(fFilename);
+    finally
+      yaml.Free;
+    end;
+  except
+    on e : Exception do raise EAppConfig.Create(e.Message);
+  end;
+end;
+
+
+procedure TAppConfigYMALProvider.SetFileName(const Value: string);
+begin
+  fFilename := Value;
+  if Assigned(fFileMonitor) then fFileMonitor.Free;
+  if fReloadIfFileChanged then CreateFileMonitor;
+end;
+
+procedure TAppConfigYMALProvider.SetReloadIfFileChanged(const Value: Boolean);
+begin
+  if Value = fReloadIfFileChanged then Exit;
+  fReloadIfFileChanged := Value;
+  if Assigned(fFileMonitor) then fFileMonitor.Free;
+  if fReloadIfFileChanged then CreateFileMonitor;
+end;
+
+procedure TAppConfigYMALProvider.SetReloadNotify(aNotifyReload: TLoadConfigEvent);
+begin
+  fNotifyReload := aNotifyReload;
+end;
+
+{ TAppConfigYAML }
+
+constructor TAppConfigYAML.Create(const aFilename : string; aReloadIfFileChanged : Boolean = False);
+begin
+  inherited Create(TAppConfigYMALProvider.Create(aFileName,aReloadIfFileChanged));
+  TAppConfigYMALProvider(fProvider).SetReloadNotify(ReloadNotify);
+end;
+
+destructor TAppConfigYAML.Destroy;
+begin
+  inherited;
+end;
+
+function TAppConfigYAML.GetProvider: TAppConfigYMALProvider;
+begin
+  if not Assigned(fProvider) then raise EAppConfig.Create('No provider assigned!');
+  Result := TAppConfigYMALProvider(fProvider);
+end;
+
+procedure TAppConfigYAML.ReloadNotify;
+begin
+  Self.Load;
+end;
+
+function TAppConfigYAML.ToYAML: string;
+var
+  serializer : TYamlSerializer;
+begin
+  serializer := TYamlSerializer.Create(slPublishedProperty,fProvider.UseEnumNames);
+  try
+    Result := serializer.ObjectToYaml(Self);
+  finally
+    serializer.Free;
+  end;
+end;
+
+procedure TAppConfigYAML.FromYAML(const yaml: string);
+var
+  serializer : TYamlSerializer;
+begin
+  serializer := TYamlSerializer.Create(slPublishedProperty,fProvider.UseEnumNames);
+  try
+    serializer.YamlToObject(Self,yaml);
+  finally
+    serializer.Free;
+  end;
+end;
+
+end.