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%Stream.DynamicCharacter

stream class %Stream.DynamicCharacter extends %Stream.Object

%Stream.DynamicCharacter character stream containing the textual value of an element of a %DynamicAbstractObject. It is particularly useful for holding the value of a %DynamicAbstractObject element with a textual value that would exceed the capacity of an ObjectScript string variable. A %Stream.DynamicCharacter object is readonly and it cannot be modified or saved. But it can be copied to any other %Stream class object that does support modification and saving.

The only way to create a %Stream.DynamicCharacter is by making a method call that looks like dao.%Get(key,default,"stream") where dao is n object reference to a subclass of %DynamicAbstractObject; and where key is the key name value of an element of a %DynamicObject or the index value of an element of a %DynamicArray.

Property Inventory (Including Private)

Method Inventory (Including Private)

Parameters

parameter BUFLEN = 32000;
Default read length when buffering
parameter READLEN = 32000;
Default length for a Read.

Properties (Including Private)

property DAOPos as %Integer [ Private , InitialExpression = 1 ];
Property methods: DAOPosDisplayToLogical(), DAOPosGet(), DAOPosIsValid(), DAOPosLogicalToDisplay(), DAOPosNormalize(), DAOPosSet()
property DAOSize as %Integer [ Private ];
Property methods: DAOSizeDisplayToLogical(), DAOSizeGet(), DAOSizeIsValid(), DAOSizeLogicalToDisplay(), DAOSizeNormalize(), DAOSizeSet()
property LineTerminator as %String (MAXLEN = 10) [ InitialExpression = $char(13,10) , Transient ];
The line terminator we use for this stream. It defaults to $CHAR(13,10), CR/LF. Maximum length is 10 characters.
Property methods: LineTerminatorDisplayToLogical(), LineTerminatorGet(), LineTerminatorIsValid(), LineTerminatorLogicalToDisplay(), LineTerminatorLogicalToOdbc(), LineTerminatorNormalize(), LineTerminatorSet()
property Position as %Integer [ Calculated ];
Position is a read-only property containing the current character position of the %Stream.DynamicCharacter. The next Read()() method call will start reading at this character position. Character position 1 is the position of the first character in the stream. When Position contains the value 1 then the first Read()() (after creation of the stream or after execution of the Rewind()() method) has not yet been executed. After the last character has been read then Position will again contain the value 1.
Property methods: PositionDisplayToLogical(), PositionGet(), PositionIsValid(), PositionLogicalToDisplay(), PositionNormalize()
property Size as %Integer [ Calculated ];
Size is a read-only property containing the current size of the %Stream.DynamicCharacter in characters
Property methods: SizeDisplayToLogical(), SizeGet(), SizeIsValid(), SizeLogicalToDisplay(), SizeNormalize()

Methods (Including Private)

private classmethod %DeleteData(streamvalue As %String, concurrency As %Integer) as %Status [ Language = objectscript ]
private classmethod %GetLockReference(pLocation As %String(MAXLEN="")="", pId As %String(MAXLEN="")="") as %String [ Language = objectscript ]
Returns the global reference used to lock the current stream object.
method %IsModified() as %Integer [ Language = objectscript ]
Inherited description: Returns true (1) if a property of this instance has been modified, otherwise false (0). A TRUE result does not necessarily mean that any property has actually been changed. If %IsModified() returns false then the object has not been modified. There are some situations where we simply cannot efficiently detect a change in value. In these cases we will set the modified status of the property.
method %IsNull() as %Boolean [ Language = objectscript ]
Returns true if this is a "NULL" stream; that is, a stream which has never been written to and saved. This is used by the InterSystems IRIS ODBC server. But a %Stream.DynamicCharacter is never NULL, even if it only contains the empty string.
private method %LoadData(id As %String) as %Status [ Language = objectscript ]
method %LocationSet(val As %String) as %Status [ Language = objectscript ]
private classmethod %LogicalToStorage(val As %String) as %String [ Language = objectscript ]
method %NormalizeObject() as %Status [ Language = objectscript ]
Inherited description: Normalizes all of an object's property values by invoking the data type Normalize methods. Many data types may allow many different representations of the same value. Normalization converts a value to its cannonical, or normalized, form.
method %ObjectModified() as %Integer [ Language = objectscript ]
Inherited description: This method is somewhat similar to %IsModified but it also checks to see if swizzled references would cause the object to become modified should they be serialized. This works on the assumption that a reference to a persistent object will never be modified if the ID has already been assigned. For references to serial objects, a call to %ObjectModified indicates whether or not the serialized value is different. If the reference to a swizzled object is different from the initial object state then the $$$objModAll macro will already return true. Reference the Set code. Returns true (1) if this instance has been modified, otherwise false (0).
private method %OnClose() as %Status [ Language = objectscript ]
Inherited description: This callback method is invoked by the %Close() method to provide notification that the current object is being closed.

The return value of this method is ignored.

private method %OnConstructClone(object As %RegisteredObject, deep As %Boolean = 0, ByRef cloned As %String) as %Status [ Language = objectscript ]
Inherited description: This callback method is invoked by the %ConstructClone() method to provide notification that a clone of an object is being created. It passes in the oref of the object that was cloned in object.

If this method returns an error then the object will not be created.

private method %OnNew(initval) as %Status [ Language = objectscript ]
Inherited description: This callback method is invoked by the %New() method to provide notification that a new instance of an object is being created.

If this method returns an error then the object will not be created.

It is passed the arguments provided in the %New call. When customizing this method, override the arguments with whatever variables and types you expect to receive from %New(). For example, if you're going to call %New, passing 2 arguments, %OnNew's signature could be:

Method %OnNew(dob as %Date = "", name as %Name = "") as %Status If instead of returning a %Status code this returns an oref and this oref is a subclass of the current class then this oref will be the one returned to the caller of %New method.

private method %OnRollBack() as %Status [ Language = objectscript ]
Inherited description: This callback method is invoked by the %Save() method to provide notification that a save transaction is being rolled back.

If this method returns an error then the rollback operation will be aborted.

private method %SaveData(ByRef sid As %String) as %Status [ Language = objectscript ]
private classmethod %StorageToLogical(val As %String) as %String [ Language = objectscript ]
method %ValidateObject(force As %Library.Integer = 0, checkserial As %Library.Boolean = 1) as %Status [ Language = objectscript ]
Inherited description: This method validates an object. The %Save method of a persistent class calls it before filing any objects in the database. The %ValidateObject method of a referencing object can call it. You can also call it explicitly at any time.

%ValidateObject() does the following:

  1. It tests if any required property values are missing.
  2. If the PROPERTYVALIDATION class parameter is set to ValidateOnSave, it validates each non-null property value by calling the property method IsValid on each literal property and the object's %ValidateObject method for object-valued properties.
  3. If present, it will call a user-supplied %OnValidateObject() method.

If any of these tests fail, %ValidateObject() immediately returns an error value. It is up to the caller of %ValidateObject to process the error value.

unused is not used. checkserial will force the checking of any serial properties by calling their %ValidateObject methods after swizzling this property.

Returns a %Status value indicating success or failure.

private method BuildValueArray(ByRef subvalue As %String) as %Status [ Language = objectscript ]
Callback for searchable stream
method Clear(permanent As %Boolean = 1) as %Status [ Language = objectscript ]

Not supported. %Stream.DynamicCharacter is readonly.

method CopyFrom(source As %Stream.Object) as %Status [ Language = objectscript ]

Not supported. %Stream.DynamicCharacter is readonly.

method Flush() as %Status [ Language = objectscript ]
Inherited description: Flush any output in the stream not already saved.
method IsNull() as %Boolean [ Language = objectscript ]
Returns true if this is a "NULL" stream; that is, a stream which has never been written to and saved. This is used by the InterSystems IRIS ODBC server. But a %Stream.DynamicCharacter is never NULL, even if it only contains the empty string.
method MoveTo(position As %Integer) as %Boolean [ Language = objectscript ]
Move to this position in the stream. If this succeeds then return true, else return false.

MoveTo()(1) is equivalent to a Rewind()(). MoveTo()(1) will always succeed and it will position the %Stream.DynamicCharacter at character position 1 even if the %Stream.DynamicCharacter contains no characters. Moving to position 1 (or earlier) will be at the first character of the stream; position 2 will be at the second character of the stream, etc.

method MoveToEnd() as %Status [ Language = objectscript ]

Not supported. %Stream.DynamicCharacter is readonly.

method OutputToDevice(ByRef len As %Integer = -1) as %Status [ Language = objectscript ]
Write out len characters of the stream to the current device starting from the current position. If len is omitted or set to -1 then the OutputToDevice() method will write out the entire stream starting at the beginning and then rewind back to the beginning. If len>0 and we are unable to write len characters because we reach the end of the stream then we will stop writing and set the AtEnd property to 1. Otherwise, we will leave the stream positioned after the last character written to the device. If parameter len is passed by reference and if no error occurs then the number of characters actually written to the output device will be assigned to len. If zero characters are written because we are already positioned at the end of the stream then len will be assigned to -1. If an error occurs while writing the device then len will be assigned to -2, an error %Status value will be returned and the stream will rollback to its original position.
method PositionGet() as %Integer [ Language = objectscript ]
Implements Property Position which contains the current position within the data stream.
method Read(ByRef len As %Integer = ..#READLEN, ByRef sc As %Status) as %String [ Language = objectscript ]
Inherited description: 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 Read() will return a null string (""). If no len is passed in, ie. 'Read()()' 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 Rewind() if you want to read a stream from the beginning again. Calling Read() after Write() implicitly ends the Write() 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.

method ReadLine(ByRef len As %Integer = ..#READLEN, ByRef sc As %Status, ByRef eol As %Boolean) as %String [ Language = objectscript ]
Inherited description: 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 %Status() 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 ! } }
method ReadLineIntoStream(ByRef sc As %Status) as %Stream.Object [ Language = objectscript ]
This reads from the stream until it finds the LineTerminator and returns a new %Stream.TmpCharacter stream containing the characters in the line. If the stream does not contain the line terminator then this can potentially be the entire stream.
method Rewind() as %Status [ Language = objectscript ]
Inherited description: Go back to the start of the stream.
method SizeGet() as %Integer [ Language = objectscript ]
Implements Property Size which contains the current size of the data stream.
method Write(data As %Library.String = "") as %Status [ Language = objectscript ]

Not supported. %Stream.DynamicCharacter is readonly.

method WriteLine(data As %Library.String = "") as %Status [ Language = objectscript ]

Not supported. %Stream.DynamicCharacter is readonly.

Inherited Members

Inherited Properties (Including Private)

Inherited Methods (Including Private)

Subclasses

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