HL7PlusSegment

*All example code is in Visual Basic.Net

'Where MyController is a HL7PlusController object

Dim oMSg As HL7PlusMessage = MyController.NewHL7PlusMessage()

If IsNothing(oMSg) Then

MessageBox.Show("An Error Occurred: " & MyController.LastError, "Error")

Return

End If

'oMsg is now an EMPTY HL7 message.

'From this point on we don't have to worry about HL7PlusController Errors

'In an EMPTY message I MUST add the MSH segment first

Dim oMSH As HL7PlusSegment = oMSg.AddEmptySegment("MSH")

'---Now let's play and set some field values.

oMSH.Field(7).ComponentValue(1) = MyController.HL7Now

oMSH.Field(7).ComponentValue(2) = "S"

oMSH.Field(9).ComponentValue(1) = "ADT"

oMSH.Field(9).ComponentValue(2) = "A01"

Property Name	Data Type	Description
Field	HL7PlusField	While this property is read-only you can change the value(s) contained in the field. This property also takes 2 parameters. Parameter 1: Index (Int32) the index starting with field #1 (for the MSH Segment see Working with the MSH Segment below). Parameter 2: OPTIONAL blnPadToIfNotPresent (Boolean) Default is TRUE. This parameter is very important. If you set it to False and there is no Field(Index) then Nothing is returned. If it is set to TRUE (the Default) then before the object is returned to you, the segment will pad fields out to INDEX. Example: If you enter this code oSegment.Field(200).Value = "SomeValue" then the HL7PlusSegment object will contain 200 HL7PlusField objects after the call. See FieldCount below.
FieldCount	Int32	The number of HL7PlusField objects the segment contains.
FieldsWithInvalidData	List(of HL7PlusField)	A list of HL7PlusField objects where the ValueIsValid property is False.
Index	Int32	The Index of the HL7PlusSegment object. Will also be the ordinal position of the segment object within the message. NOTE: The MSH segment is always #1.
ParentMessage	HL7PlusMessage	The parent HL7PlusMessage object which contains the segment.
SegmentName	String	Get / Set the name of the segment. Be very careful with this one.
StructureIsValid	Boolean	Evaluates the segment for structural errors like invalid segment name.
Value	String	Get / Set the entire raw value of the HL7PlusSegment. Using this value to Set the HL7PlusSegment value should be considered an advanced option. It is possible to corrupt your message doing this.
ValueIsValid	Boolean	Evaluates the ValueIsValid property of each HL7PlusField object the segment contains. NOTE: This property also queries the StructureIsValid property

Method:	Clear()
Paramters:	None
Return Value:	None
Description:	Clears the HL7PlusSegment of all HL7PlusField objects

Method:	PadFieldsTo(MaxFields)
Paramters:	1: MaxFields (Int32)
Return Value:	Boolean
Description:	Add HL7PlusField objects to the segment until FieldCount = MaxFields. If FieldCount is already >= MaxFields then nothing happens.

Method:	ScrubAllInvalidFields(OPTIONAL ScrubAllEscapes = False, Optional ScrubAllSubComponents = False, Optional ScrubAllRepeats = False)
Paramters:	1: OPTIONAL ScrubAllEscapes Boolean- Default = False. 2: OPTIONAL ScrubAllSubComponents Boolean- Default = False. 3: OPTIONAL ScrubAllRepeats Boolean- Default = False.
Return Value:	Boolean
Description:	Calls the Scrub() method for every HL7PlusField item in FieldsWithInvalidData. See Validating Data for Scrub Rules.

Method:	TrimFieldsTo(MaxFields)
Paramters:	1: MaxFields (Int32)
Return Value:	Boolean
Description:	Removes HL7PlusField objects from the segment until FieldCount = MaxFields. If FieldCount is already <= MaxFields then nothing happens.

A HL7PlusMessage object can contain only ONE MSH segment. And working with the HL7PlusSegment object which represents the MSH segment has some restrictions. The most important takeaway is:

Be careful when working with the MSH Segment!

*All example code is in Visual Basic.Net

Consider the following example where oMsg is a HL7PlusMessage object:

Dim oMSH As HL7PlusSegment = oMSg.AddEmptySegment("MSH")

IF oMSG is NOT an EMPTY HL7PlusMessage an exception will occur and oMSH will be Nothing.

You cannot access Field(1) or Field(2) of an HL7PlusSegment object for the MSH segment. This is because field 1 of the MSH segment isn't really a field, it's the FieldDelimiter, and Field 2 also isn't really a field, it's the encoding characters.

You cannot rename the MSH segment. If you do your HL7PlusMessage will be corrupted.

If you use the .Value property to SET the Value of the MSH segment you can corrupt the message unless it is formatted correctly. This is true of all segments but is especially true of the MSH segment. So another important takeaway here is:

Be EXTREMELY careful when using the Value property to SET the value of a HL7PlusSegment Object!

This object class uses our standard HL7PlusException Class interface for error handling wherever possible.

See the HL7PlusException Implementation Reference

Class Name:	HL7PlusSegment
HL7+ Category:	Restricted (Accessed through the HL7PlusMessage object)
Description:	Object representation of 1 segment in a HL7PlusMessage