Sajo Jacob

CustomActionData in WiX with Deferred Custom Actions

Here is a major gotcha that you will encounter when you try to configure your product with 

deferred actions using configurable properties during the installation.

Deferred actions do NOT have access to the MSI session objects which means that if you try 

to get the value of a property set by the installer like:
 
Value = Session.Property( "Property1" )
 
in a VBScript custom action which is deferred, It will return null. Yes, you just lost the 
original value of Property1 during deferred custom actions.

Here is where CustomActionData comes to the rescue, let’s see how this works

Your deferred Custom Action:

<CustomAction Id=" MYCustomDeferredAction " Return="check" Execute="deferred"

BinaryKey="MYVBSCRIPT" VBScriptCall=" MyVBScriptMethod" />

Now let’s create a new custom action which will run as immediate: 

<!--Note I am passing 2 values delimted by a ‘,’ in this example-->
<CustomAction Id=" SetCustomActionDataValue " Return="check" Property="MYCustomDeferredAction" 

Value=""[Value1]","[Value2]"" />

And in the InstallExecuteSequence place the CustomActionData custom action before the

 actual custom action is executed:

<Custom Action="SetCustomActionDataValue" After="CAction1">
    <![CDATA[ ( Place any conditions here…)]]>
</Custom>

<Custom Action=" MYCustomDeferredAction " After=" SetCustomActionDataValue ">
    <![CDATA[ ( Place any conditions here…)]]>
</Custom>

 

and you are done!

' VBScript source code

Delim = ","

strArgs = Session.Property("CustomActionData")

Args = Split( strArgs, Delim )

Value1 = Args(0)

Value2= Args(1)