README

SmartPointer for Delphi

This unit provides a generic SmartPointer class in Delphi, designed to manage object lifecycle automatically, acting as a garbage collector. It simplifies memory management by ensuring that objects are automatically freed when they are no longer needed, thus preventing memory leaks.

Overview

The SmartPointer class is a generic wrapper around Delphi objects that implements reference-counting. It ensures that the object it manages is automatically destroyed when the reference count drops to zero. This class can be used in any Delphi project that requires simplified memory management, removing the need to manually free objects.

Features

• Automatic object destruction when the reference count reaches zero.
• Supports any class that has a parameterless constructor (constructor constraint).
• Prevents memory leaks by managing the object lifecycle.
• Can be created with a new object or assigned an existing one.

Usage

Installation

To use the SmartPointer class in your project, include the Classe.SmartPointer unit in your Delphi application:

uses
  Classe.SmartPointer;

Creating a SmartPointer

Option 1: Automatic Object Creation

You can create a SmartPointer that will automatically instantiate the object:

var
  MyPointer: ISmartPointer<TMyClass>;
begin
  MyPointer := TSmartPointer<TMyClass>.Create;
  MyPointer.DoSomething; // Access your object as needed
end; // Object is automatically freed when the reference goes out of scope

Option 2: Using an Existing Object

Alternatively, create the SmartPointer with an already instantiated object:

var
  MyPointer: ISmartPointer<TMyClass>;
begin
  MyPointer := TSmartPointer<TMyClass>.Create(TMyClass.Create);
  MyPointer.DoSomething; // Access the object through the smart pointer
end; // The object is freed automatically

Option 3: Using an Existing Object with Separate Instantiation

You can also pass a pre-existing, separately instantiated object to the SmartPointer:

var
  MyObject: TMyClass;
  MyPointer: ISmartPointer<TMyClass>;
begin
  MyObject := TMyClass.Create;
  MyPointer := TSmartPointer<TMyClass>.Create(MyObject);
  MyPointer.DoSomething; // Access the object through the smart pointer
end; // The object is freed automatically

Another example: Using TClientDataSet and Accessing Fields

The SmartPointer can also be used with database components, such as TClientDataSet. Here's an example showing how to create and access fields in TClientDataSet:

uses
  Data.DB, Datasnap.DBClient, Classe.SmartPointer;

var
  ClientDataSetPointer: ISmartPointer<TClientDataSet>;
begin
  ClientDataSetPointer := TSmartPointer<TClientDataSet>.Create(TClientDataSet.Create(nil));
  // Note: You need to define the fields here before calling CreateDataSet
  ClientDataSetPointer.CreateDataSet;
  ClientDataSetPointer.Append;
  ClientDataSetPointer.FieldByName('MyField').AsString := 'Hello, World!';
  ClientDataSetPointer.Post;

  // Access data
  ShowMessage(ClientDataSetPointer.FieldByName('MyField').AsString);
end; // TClientDataSet is freed automatically

Accessing the Object

To access the object managed by the SmartPointer, you can directly call methods or access properties without needing to invoke any specific method. The SmartPointer automatically handles the reference to the object.

MyPointer.DoSomething;  // No need to call Invoke

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