Specifying Extension Properties

In the Custom Dialog Builder for Extensions, custom dialogs that you build are contained within an extension. In the current example, you are building a custom dialog for the SPSSINC RASCH DEMO extension command. You can add the files for the SPSSINC RASCH DEMO extension command to the extension that already contains your custom dialog. When the extension is installed, the custom dialog and the associated extension command files are installed.

From the menus in the Custom Dialog Builder, choose:
Extension > Properties

The Extension Properties dialog is displayed. From the Extension Properties dialog, you can add the files for the SPSSINC RASCH DEMO extension command and you can set properties such as Integration Plug-ins that are required to run the extension.

Figure 1. Required tab of Extension Properties dialog
Enter SPSSINC RASCH DEMO in the Name field.
Enter Demonstration extension for wrapping the R rasch function in the Summary field.
Keep the default values of the Version and Minimum SPSS Statistics Version fields.
Click Add to add the files SPSSINC_RASCH_DEMO.R and SPSSINC_RASCH_DEMO.xml that specify the SPSSINC RASCH DEMO extension command. The files are available in the Samples directory (under the installation directory).
Click the Optional tab and select Dependencies.
Figure 2. Dependencies settings of Extension Properties dialog
Check the Integration Plug-in for R required box. The SPSSINC RASCH DEMO extension requires the IBM® SPSS® Statistics - Integration Plug-in for R since it is implemented in R.
Users are alerted at install time if they don't have a required plug-in.
Click anywhere in the Required R Packages control to highlight the entry field and enter ltm.
When the extension is installed, IBM SPSS Statistics checks if the required R packages exist on the user's machine and attempts to download and install any that are missing.
Click Continue.