On Fri, Sep 19, 2014 at 9:08 PM, Boian Mitov <mi...@mitov.com> wrote:
> Hi Hans, > > I am sorry to disagree with you. > +1. > The attributes in particular allow you to do real magic, and reduce your > code by at least 4 times, and speed up your development up to 10 times. > I tested the new RTTI in Delphi XE and it reduced my typing alot. See: (* credits: https://code.google.com/p/delphi-orm/ *) var person: TPerson; oid: Integer; begin person := TPerson.Create('Daniele', 'Teti',32); Session.Save(person); oid := person.id; person.Free; ... person := Session.Load<TPerson>(oid); WriteLn(‘Person name is: ‘, person.FirstName); person.Free; end; I'm using an approach like this in Android development (with Java: http://ormlite.com/sqlite_java_android_orm.shtml). We have done that in Delphi. > I actually did a session in the PasCon few days on that. > Here is example: > > TMyInterfacedClass1 = class; > > [CreateType( typeinfo( TMyInterfacedClass1 ))] // Specifies the default > creation type as TMyInterfacedClass1 > IMyInterface = interface > ['{EB12CEBD-42C3-4259-AE2C-70267B67F454}'] > > function GetValue() : String; > > end; > > TMyInterfacedClass1 = class( TBasicInterfacedObject, IMyInterface ) > public > function GetValue() : String; > > end; > > TMyInterfacedClass2 = class( TBasicInterfacedObject, IMyInterface ) > public > function GetValue() : String; > > end; > > TMyNestedClass = class( TBasicObject ) > protected > [Default( True )] // FValue1 will be initialized with True > FValue1 : Boolean; > > [Default( 11.5 )] // FValue2 will be initialized with 11.5 > FValue2 : Real; > > [AutoManage( TMyInterfacedClass2 )] // FInterfaceValue will be created as > TMyInterfacedClass2 > FInterfaceValue : IMyInterface; > > public > property Value1 : Boolean read FValue1; > property Value2 : Real read FValue2; > property InterfaceValue : IMyInterface read FInterfaceValue; > > end; > > TMyClass = class( TBasicObject ) > protected > [Default( 100 )] // FValue1 will be initialized with 100 > FValue1 : Integer; > > [Default( 'Helo World!' )] > FValue2 : String; // FValue1 will be initialized with 'Helo World!' > > [AutoManage] // FNested will be automatically created and destroyed > FNested : TMyNestedClass; > > [AutoManage( TStringList )] // FStrings will be automatically created as > TStringList and destroyed > // [AutoDestroy] // - If AutoDestroy is used instead of AutoManage, the > object will not be created but will be automatically destroyed! > FStrings : TStrings; > > [AutoManage] // FNested will be automatically created as TStringArrayList > FStringArrayList : IStringArrayList; > > [AutoManage] // FInterfaceValue will be created as TMyInterfacedClass1 > FInterfaceValue : IMyInterface; > > public > property Value1 : Integer read FValue1; > property Value2 : String read FValue2; > property Nested : TMyNestedClass read FNested; > property Strings : TStrings read FStrings; > property StringArrayList : IStringArrayList read FStringArrayList; > property InterfaceValue : IMyInterface read FInterfaceValue; > > end; > I intend to do the following if the new RTTI (of Delphi XE) come in FPC 2.8.0 (like Java annotations): TPerson = class(TObject) // or TSerializableObject published { @code(Id): Field used to store the ID of each *Person*. } ['integer', 'notnull', 'autoinc', 'primarykey'] property Id: Int64; { @code(Name): Field used to store the name of each *Person*. } ['string:50', 'nonull', 'unique'] property Name: string; end; And from this object above, my framework will generate the metadata for the table creation, generation of HTML/JS forms, generation of object mappers, generation of CRUD web actions with their REST paths, generation of documentation and UML, among others. > As you can see all the management of all the classes and interfaces is > done without the need of even one line of code. > No constructors, no destructors, nothing. > This alone cuts vast amounts of code. > This however only scratches the surface of the RTTI power. You have no > idea about some of the other possibilities ;-) . > The RTTI does not only work with properties and fields, but with functions > as well, allowing easy implementation of RPC and network distributed > execution. > It is a whole ball game. > Frankly some of the arguments you provide ware the same I have heard 20 > years ago when I programmed in C++ and people ware telling me I should be > doing it in Assembler. > They simply had no idea what power OOP had as example, as you probably > have no idea what is the real power of modern RTTI when properly used. > > I am at the same time huge fan of strong typed languages. The advanced > RTTI does not really mean the code should and will not be strongly typed. > Indeed I have done my own RTTI API which is stronger typed than the one > Delphi provides. I was very curious to see your RTTI API. :-) -- Silvio Clécio My public projects - github.com/silvioprog
_______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
