LibraryStream Class Reference

Adapts IO stream classes to provide a legacy Library.AbstractStream interface. More...

Inheritance diagram for LibraryStream:

Collaboration diagram for LibraryStream:

Public Member Functions
_.Library.Status	Clear ()
	Clear the contents of this Stream from permanent storage. More...
_.Library.Status	CopyFrom (_.Stream.Object source)
	Copy the contents of the given source IO, Library or Stream stream to the wrappered IO stream.
_.Library.Integer	FindAt (_.Library.Integer position, _.Library.RawString target, _.Library.RawString tmpstr)
	Find the first occurrence of target in the stream starting the. More...
_.Library.Status	Flush ()
	Flush any output in the stream not already saved.
_.Library.Status	InputFromDevice (_.Library.Integer len, _.Library.Integer timeout)
	Input len characters from the current device into the stream. More...
_.Library.Boolean	MoveTo (_.Library.Integer position)
	Move to this position in the stream. More...
_.Library.Status	MoveToEnd ()
	Move to the end of the stream so the next <METHDO>Write</METHOD> will be appended to the end. More...
_.Library.Status	OutputToDevice (_.Library.Integer len)
	Write out len characters of the stream to the current device starting from the current position. More...
_.Library.Status	OutputToDeviceAt (_.Library.Integer position, _.Library.Integer length)
	Output the stream to the current device starting at position of length. More...
_.Library.RawString	Read (_.Library.Integer len, _.Library.Status sc)
	Reads up to len characters from the current position. More...
_.Library.RawString	ReadLine (_.Library.Integer len, _.Library.Status sc, _.Library.Boolean eol)
	Read a line from the stream. More...
_.Library.Status	Rewind ()
	Go back to the start of the stream.
_.Library.Status	Write (_.Library.RawString data)
	Appends the string data to the stream and advances the. More...
_.Library.Status	WriteLine (_.Library.RawString data)
	Appends the string data along with a line terminator to the stream and advances the. More...
Public Member Functions inherited from AbstractStream
_.Library.Status	OnClose ()
	This callback method is invoked by the <METHOD>Close</METHOD> method to. More...
_.Library.Status	CopyFrom (_.Stream.Object source)
	Copies the contents of source into this Stream. More...
_.Library.Boolean	DeleteAttribute (_.Library.String name)
	Removes this attribute variable from the collection. More...
_.Library.String	GetAttribute (_.Library.String name, _.Library.String default)
	Retrieves the named attribute value.
_.Library.String	GetStreamId ()
	Returns an full id value (including class name) with which the Stream implementation has stored. More...
_.Library.Boolean	IsDefinedAttribute (_.Library.String name)
	Returns true if the named attribute variable exists in the collection, false otherwise.
_.Library.Boolean	IsNull ()
	Returns true if this is a "NULL" stream; that is, a stream which has never. More...
_.Library.String	NextAttribute (_.Library.String name)
	Retrieves the next attribute variable name in the sequence, skip any '' names.
_.Library.AbstractStream	ReadLineIntoStream ()
	This reads from the stream until it find the <property>LineTerminator</property> and returns. More...
_.Library.Status	SaveStream ()
	Deprecated method, use <method>Save</method> instead. More...
	SetAttribute (_.Library.String name, _.Library.String value)
	Inserts an attribute variable by name into the collection.
_.Library.Status	WriteLine (_.Library.RawString data)
	Appends the string data along with a line terminator to the stream and advances the. More...
Public Member Functions inherited from Object
_.Library.Status	AcquireLock (locktype)
	Acquires a lock for the current instance. More...
_.Library.Status	OnAfterSave (_.Library.Boolean insert)
	This callback method is invoked by the <METHOD>Save</METHOD> method to. More...
_.Library.Status	OnBeforeSave (_.Library.Boolean insert)
	This callback method is invoked by the <METHOD>Save</METHOD> method to. More...
_.Library.Status	OnOpen ()
	This callback method is invoked by the <METHOD>Open</METHOD> method to. More...
_.Library.Status	OnReload ()
	This callback method is invoked by the <METHOD>Reload</METHOD> method to. More...
_.Library.Status	OnRollBack ()
	This callback method is invoked by the <METHOD>Save</METHOD> method to. More...
_.Library.Status	CopyFrom (_.Stream.Object source)
	Copies the contents of source into this Stream. More...
_.Library.Status	CopyFromAndSave (_.Stream.Object source)
	Copy the stream from source into the current stream ignoring anything already in the current stream. More...
_.Library.Integer	FindAt (_.Library.Integer position, _.Library.RawString target, _.Library.RawString tmpstr, _.Library.Boolean caseinsensitive)
	Find the first occurrence of target in the stream, starting the search at position. More...
_.Library.String	ReadSQL (_.Library.Integer start, _.Library.Integer end)
	SQL specific method for reading stream data.
_.Library.Status	SerializeToSyncSet (_.SYNC.SyncSet ss, _.Library.Integer iPtr, _.Library.String property)
	SerializeToSyncSet copies the stream value from the current object to the sync set global. More...
_.Library.Status	SyncStreamIn (_.SYNC.SyncSet ss, _.Library.Integer iPtr, _.Library.String property)
	SyncStreamIn copies the stream value from the sync set global into the current object.
Public Member Functions inherited from RegisteredObject
_.Library.Status	OnAddToSaveSet (_.Library.Integer depth, _.Library.Integer insert, _.Library.Integer callcount)
	This callback method is invoked when the current object is added to the SaveSet,. More...
_.Library.Status	OnConstructClone (_.Library.RegisteredObject object, _.Library.Boolean deep, _.Library.String cloned)
	This callback method is invoked by the <METHOD>ConstructClone</METHOD> method to. More...
_.Library.Status	OnNew ()
	This callback method is invoked by the <METHOD>New</METHOD> method to. More...
_.Library.Status	OnValidateObject ()
	This callback method is invoked by the <METHOD>ValidateObject</METHOD> method to. More...

Public Attributes
	AtEnd
	More...
	IOStream
	The IO.I.Stream that we are wrapping. More...
	LastModified
	More...
	LineTerminator
	More...
	Size
	More...
Public Attributes inherited from AbstractStream
	Attributes
	An array of strings containing any attribute values associated with this stream. More...
	LineTerminator
	Type of line terminator we use for this stream, defaults to Cr/Lf. More...
Public Attributes inherited from Object
	AtEnd
	The AtEnd property is set to true (1) when, during a read,. More...
	LastModified
	LastModified is a read-only property containing the <class>TimeStamp</class> of More...
	Size
	Size is a read-only property containing the current size of the stream (in bytes More...

Additional Inherited Members
Static Public Member Functions inherited from AbstractStream
_.Library.Status	DeleteStream (_.Library.ObjectIdentity oid, _.Library.Integer concurrency)
	Deprecated method, use <method>Delete</method> instead. More...
Static Public Member Functions inherited from Object
_.Library.String	GetLockReference (_.Library.String pLocation, _.Library.String pId)
	Returns the global reference used to lock the current stream object. More...
_.Library.Status	OnDelete (_.Library.ObjectIdentity oid)
	This callback method is invoked by the <METHOD>Delete</METHOD> method to. More...
_.Library.String	IsCharacter ()
	Return true if this is a character stream and false if it is a binary stream.
_.Library.Boolean	StreamOIDIsNull (_.Library.ObjectIdentity soid)
	Return true if this stream oid is a null stream and false if the stream is not null.
Static Public Attributes inherited from AbstractStream
	MAXLEN = None
	The maximum number of characters (or bytes) allowed in a stream.
	PROPERTYVALIDATION = None
	Turns off property validation.
Static Public Attributes inherited from Object
	DEFAULTCONCURRENCY = None
Static Public Attributes inherited from RegisteredObject
	CAPTION = None
	Optional name used by the Form Wizard for a class when generating forms. More...
	JAVATYPE = None
	The Java type to be used when exported.
	PROPERTYVALIDATION = None
	This parameter controls the default validation behavior for the object. More...

Detailed Description

Adapts IO stream classes to provide a legacy Library.AbstractStream interface.

Member Function Documentation

Clear()

_.Library.Status Clear

(

)

Clear the contents of this Stream from permanent storage.

This will remove the permanent stream storage and

any temporary stream and initialise the stream to its initial state that it starts in, including removing all the stream attributes.

Returns a <CLASS>Status</CLASS> value indicating success or failure.

Reimplemented from Object.

FindAt()

_.Library.Integer FindAt	(	_.Library.Integer	position,
		_.Library.RawString	target,
		_.Library.RawString	tmpstr
	)

Find the first occurrence of target in the stream starting the.

search at position. It returns the position at this match starting at the beginning of the stream. If it does not find the target string then return -1. If position=-1 then start searching from the current location and just return the offset from the last search, useful for searching through the entire file. If you are doing this you should pass in tmpstr by reference in every call which is used as a temporary location to store information being read so the next call will start where the last one left off.

InputFromDevice()

_.Library.Status InputFromDevice	(	_.Library.Integer	len,
		_.Library.Integer	timeout
	)

Input len characters from the current device into the stream.

This is equivalent to doing a series of

reads and calling <METHOD>Write</METHOD> for each of them but it may be optimised by the subclasses. On return len will be the number of characters still to read in (if no timeout has occured this should be 0).

Reimplemented from Object.

MoveTo()

_.Library.Boolean MoveTo

(

_.Library.Integer

position

)

Move to this position in the stream.

If this suceeds then return

true, else return false. Note this implementation is not efficient because it searches from the start of the stream, it can be improved upon in specific subclasses. Note that moving to position 1 will be at the start of the stream, position 2 will be at the second character of the stream, etc.

Reimplemented from Object.

MoveToEnd()

_.Library.Status MoveToEnd

(

)

Move to the end of the stream so the next <METHDO>Write</METHOD> will be appended to the end.

This allows you to read from a stream, then MoveToEnd() and append new data, where just calling <METHOD>Write</METHOD> after a read will clear the stream before writing new data.

Returns a <CLASS>Status</CLASS> value indicating success or failure.

Reimplemented from AbstractStream.

OutputToDevice()

_.Library.Status OutputToDevice

(

_.Library.Integer

len

)

Write out len characters of the stream to the current device starting from the current position.

This

method is optimised for performance by the various sub classes. If len is omitted or set to -1 then it will write out the entire stream starting at the beginning.

Reimplemented from Object.

OutputToDeviceAt()

_.Library.Status OutputToDeviceAt	(	_.Library.Integer	position,
		_.Library.Integer	length
	)

Output the stream to the current device starting at position of length.

length. The length if passed by reference returns the number of characters output.

Reimplemented from Object.

Read()

_.Library.RawString Read	(	_.Library.Integer	len,
		_.Library.Status	sc
	)

Reads up to len characters from the current position.

in the stream. The current position is advanced by the number of characters read. Upon exit, len is set to the actual number of characters read. If a read occurs when the stream position is at the end of the stream, len will be set to -1 and <method>Read</method> will return a null string (""). If no len is passed in, ie. '<method>Read</method>()' then it is up to the Read implementation as to how much data to return. Some stream classes use this to optimize the amount of data returned to align this with the underlying storage of the stream.

You must call <method>Rewind</method> if you want to read a stream from the beginning again. Calling <method>Read</method> after <method>Write</method> implicitly ends the <method>Write</method> operation and rewinds to the start of the stream.

Returns a string up to len characters long. The byref argument sc will return a Status if any error occurred during the read.

Reimplemented from Object.

ReadLine()

_.Library.RawString ReadLine	(	_.Library.Integer	len,
		_.Library.Status	sc,
		_.Library.Boolean	eol
	)

Read a line from the stream.

This will look for the line terminator in the stream and

once it finds the terminator it will return the string minus the terminator character/s. If it reaches the end of the stream before it finds a terminator it will return the data it has so far, and if you specify a maximum size in len it will only read up to this number of characters. On exit len will contain the actual number of characters read. The byref argument sc will return a <method>Status</method> if any error occured during the read and the byref argument eol is true if it found the line terminator and false otherwise. So for example you can read in a stream a line at a time and output the results to the current device with:

While 'stream.AtEnd { Write stream.ReadLine(,.sc,.eol) If $$$ISERR(sc) { Write "ERROR" Quit } If eol { Write ! } }

Reimplemented from Object.

Write()

_.Library.Status Write

(

_.Library.RawString

data

)

Appends the string data to the stream and advances the.

current stream position by the number of characters in data.

Note that a write operation immediately following a read or rewind will clear out the existing data in the stream.

Returns a <CLASS>Status</CLASS> value indicating success or failure.

Reimplemented from Object.

WriteLine()

_.Library.Status WriteLine

(

_.Library.RawString

data

)

Appends the string data along with a line terminator to the stream and advances the.

current stream position by the number of characters in data plus the line terminator.

Returns a <CLASS>Status</CLASS> value indicating success or failure.

Reimplemented from Object.

Member Data Documentation

AtEnd

AtEnd

 

 

IOStream

IOStream

The IO.I.Stream that we are wrapping.

 

LastModified

LastModified

 

 

LineTerminator

LineTerminator

 

 

Size

Size