TReader¶

Generic reader object which reads component data from any given source.

Declaration¶

Source position: classesh.inc line 1998

type

  TReader = class(TFiler)
  public
    constructor Create;
    destructor Destroy;
    procedure FlushBuffer;
    procedure BeginReferences;
    procedure CheckValue;
    procedure DefineProperty;
    procedure DefineBinaryProperty;
    function EndOfList : Boolean;
    procedure EndReferences;
    procedure FixupReferences;
    procedure SkipValue;
    function NextValue : TValueType;
    procedure Read;
    procedure ReadPrefix;
    function ReadBoolean : Boolean;
    function ReadChar : AnsiChar;
    function ReadWideChar : WideChar;
    function ReadUnicodeChar : UnicodeChar;
    procedure ReadCollection;
    function ReadComponent : TComponent;
    procedure ReadComponents;
    function ReadFloat : Extended;
    function ReadSingle : Single;
    function ReadDouble : Double;
    function ReadDate : TDateTime;
    function ReadCurrency : Currency;
    function ReadIdent : RawByteString;
    function ReadInteger : LongInt;
    function ReadInt64 : Int64;
    function ReadSet : Integer;
    procedure ReadListBegin;
    procedure ReadListEnd;
    function ReadRootComponent : TComponent;
    function ReadComponentDeltaRes : TComponent;
    function ReadVariant : Variant;
    procedure ReadSignature;
    function ReadStr : RawByteString;
    function ReadString : RawByteString;
    function ReadWideString : WideString;
    function ReadUnicodeString : UnicodeString;
    function ReadValue : TValueType;
    procedure CopyValue;
    property Driver: TAbstractObjectReader; {r}
    property Owner: TComponent; {rw}
    property Parent: TComponent; {rw}
    property OnError: TReaderError; {rw}
    property OnPropertyNotFound: TPropertyNotFoundEvent; {rw}
    property OnFindMethod: TFindMethodEvent; {rw}
    property OnSetMethodProperty: TSetMethodPropertyEvent; {rw}
    property OnSetName: TSetNameEvent; {rw}
    property OnReferenceName: TReferenceNameEvent; {rw}
    property OnAncestorNotFound: TAncestorNotFoundEvent; {rw}
    property OnCreateComponent: TCreateComponentEvent; {rw}
    property OnFindComponentClass: TFindComponentClassEvent; {rw}
    property OnFindComponentClassEx: TFindComponentClassExEvent; {rw}
    property OnReadStringProperty: TReadWriteStringPropertyEvent; {rw}
    property RawMode: Boolean; {rw}
    property DelphiCompatible: Boolean; {rw}
  end;

Inheritance¶

Description¶

The TReader class is a reader class that implements generic component streaming capabilities, independent of the format of the data in the stream. It uses a driver class TAbstractObjectReader to do the actual reading of data. The interface of the TReader class should be identical to the interface in Delphi.

Note that the TReader design is such that it can read a single component from a stream. It will read all children of this component, but it is not designed to read multiple components in succession from one stream.

It should never be necessary to create an instance of this class directly. Instead, the TStream.ReadComponent call should be used.

Properties¶

Member	Visibility	Description
DelphiCompatible	public
Driver read only	public	The driver in use for streaming the data.
Owner	public	Owner of the component being read.
Parent	public	Parent of the component being read.
RawMode	public

See all Properties

Methods¶

Member	Visibility	Description
BeginReferences	public	Initializes the component referencing mechanism.
CheckValue	public	Raises an exception if the next value in the stream is not of type Value.
CopyValue	public	Copy a value to a writer.
Create	public	Creates a new reader class.
DefineBinaryProperty	public	Reads a user-defined binary property from the stream.
DefineProperty	public	Reads a user-defined property from the stream.
Destroy	public	Destroys a reader class.
EndOfList	public	Returns true if the stream contains an end-of-list marker.
EndReferences	public	Finalizes the component referencing mechanism.
FixupReferences	public	Tries to resolve all unresolved component references.
FlushBuffer	public	Flush the buffer.
NextValue	public	Returns the type of the next value.
Read	public	Read raw data from stream.
ReadBoolean	public	Reads a boolean from the stream.
ReadChar	public	Reads a character from the stream.
ReadCollection	public	Reads a collection from the stream.
ReadComponent	public	Starts reading a component from the stream.
ReadComponentDeltaRes	public
ReadComponents	public	Starts reading child components from the stream.
ReadCurrency	public	Read a currency value from the stream.
ReadDate	public	Reads a date from the stream.
ReadDouble	public
ReadFloat	public	Reads a float from the stream.
ReadIdent	public	Reads an identifier from the stream.
ReadInt64	public	Reads a 64-bit integer from the stream.
ReadInteger	public	Reads an integer from the stream.
ReadListBegin	public	Checks for the beginning of a list.
ReadListEnd	public	Checks for the end of a list.
ReadPrefix	public
ReadRootComponent	public	Starts reading a root component.
ReadSet	public	Read a set value from the stream.
ReadSignature	public	Read stream signature from the stream.
ReadSingle	public	Reads a single-type real from the stream.
ReadStr	public
ReadString	public	Reads a string from the stream.
ReadUnicodeChar	public	Read Unicode character.
ReadUnicodeString	public	Read a UnicodeString value from the stream.
ReadValue	public	Reads the next value type from the stream.
ReadVariant	public	Read a variant from the stream.
ReadWideChar	public	Read widechar from the stream.
ReadWideString	public	Read a WideString value from the stream.
SkipValue	public

See all Methods

Events¶

Member	Visibility	Description
OnAncestorNotFound	public	Handler called when the ancestor component cannot be found.
OnCreateComponent	public	Handler called when a component needs to be created.
OnError	public	Handler called when an error occurs.
OnFindComponentClass	public	Handler called when a component class reference needs to be found.
OnFindComponentClassEx	public
OnFindMethod	public	Handler to find or change a method address.
OnPropertyNotFound	public	Handler for treating missing properties.
OnReadStringProperty	public	Handler for translating strings when read from the stream.
OnReferenceName	public	Handler called when another component is referenced.
OnSetMethodProperty	public	Handler for setting method properties.
OnSetName	public	Handler called when setting a component name.

See all Events

Name	Description
TFiler	Class responsible for streaming of components.
TWriter	Object to write component data to an arbitrary format.
TAbstractObjectReader	Abstract driver class to read stored component data.