<property> Element
Declares a property.
<property name="propertyName" [internalName="propertyVariable"] />
–or–
<property name="propertyName">
<get [internalName="getFunctionName"] />
<put [internalName="putFunctionName"] />
</property>
Values
propertyName
The name of the property to expose. Unless you specify an internalName attribute, this name must match the name of a global variable that will be used to hold the property's value.propertyVariable
(Optional) The name of the global variable in the scriptlet file's <script> element that will hold the value for propertyName. If you do not include the internalName attribute, the property value is maintained in a variable named the same as propertyName. Specifying the internalName attribute allows you to use different names for the property and its corresponding global variable.getFunctionName
(Optional) The name of a procedure that is used to read the value of the property. If you include <get> element but no <put> element, the property will be read-only. If you include a <get> element but do not specify an internalName attribute, the method used to read the property value must have the name of the property plus the get_ prefix (for example, get_lastname).putFunctionName
(Optional) The name of a procedure that is used to write the value of the property. If you include a <put> element but no <get> element, the property will be write-only. If you include a <put> element but do not specify an internalName attribute, the method used to read the property value must have the name of the property plus the put_ prefix (for example, put_lastname).Tip
In XML, you can implement elements that have no content (such as the <property> element) by closing the element with />.
Remarks
Properties can be exposed as simple values. In that case, the property is treated as a global variable inside the script component file.
You can also implement properties as procedures (functions or subroutines), which allows you to calculate a property value and to control whether a property is read-only, read-write, or write-only. In this technique, properties are implemented as a procedure (function or subroutine) in a separate <script> element. The <property> element maps the name of the property to the procedures used to implement it. The names of the procedures must match the internal names you specified in the <property> element.
When putFunctionName is called, it is passed one argument that contains the value to which to set the property.
In addition to the standard syntax shown above, you can use a shorthand notation to specify information what would otherwise be added using child tags. For example, if you want to declare a property with a "get" and "put" accessor of the same name as the property, you can use the following syntax:
<property name="myproperty" get put/>
which is functionally equivalent to:
<property name="myproperty">
<get/>
<put/>
</property>
If you wanted to explicitly name those accessors differently from the default, you can use the following syntax:
<property name="myproperty" get="testget" put="testput"/>
To specify a default property, include the attribute dispid="0" in the <property> element. For details, see Exposing Properties.
Example
The following script component fragment shows the definition for four properties (sname, age, dateOfBirth, and mstatus). The sname property is a simple value. The age property is read-only, and is implemented with the function readAge. The dateOfBirth property is read-write, and is implemented with the functions readDOB and writeDOB. Finally, the mstatus property is implemented with the default functions get_mstatus and put_mstatus.
Note
A CDATA section is required to make the script in the <script> element opaque. For details, see Script Component Files and XML Conformance.
<public>
<property name="sname"/>
<property name="age">
<get internalName="readAge"/>
</property>
<property name="dateOfBirth">
<get internalName="readDOB"/>
<put internalName="writeDOB"/>
</property>
<property name="mstatus">
<get/>
<put/>
</property>
</public>
<script language="VBScript">
<![CDATA[
Dim sname ' Read-write sname property (no functions).
Dim gDOB ' Global variable used to store date of birth.
Dim gMStatus ' global variable used to store marital status.
Function readDOB()
' Gets value of dateOfBirth property.
readDOB = gDOB
End Function
Function writeDOB(newDOB)
' Sets value of dateOfBirth property.
If isDate(gDOB) Then
' Error checking.
gDOB = newDOB
End If
End Function
Function readAge()
' Calculates read-only age property.
If isDate(gDOB) Then
dobM = DatePart("m", gDOB)
dobD = DatePart("d", gDOB)
dobY = DatePart("yyyy", gDOB)
todayY = DatePart("yyyy", Date)
age = todayY - dobY
' Adjust if birthday has not yet occurred this year.
bday = DateValue(dobM & "/" & dobD & "/" & todayY)
If DateDiff("d", bday, DateValue(Date)) < 0 Then
age = age - 1
End If
readAge = age
End If
End Function
Function get_mstatus()
' Reads value of mstatus property.
get_mstatus = gMStatus
End Function
Function put_mstatus(s)
' Writes value of mstatus property.
If s = "M" Or s = "S" Then
gMStatus = s
Else
gMStatus = "?"
End If
End Function
]]>
</script>