A transform is a collection of changes applied to an installation. The Windows Installer can add or replace data in the installation database (.msi file) by applying a transform to a base installation package (using the TRANSFORMS property). For example, a transform can change all the text in an application's user interface from English to German.
The installer can only apply transforms during an installation.
The installer registers a list of transforms required by the product during the installation. The installer must apply these transforms to the installation package for the product when installing the product. If a listed transform is unavailable, and if the transform source resiliency cannot restore it, the installation will fail. A transform can modify information that is in any persistent table in the installer database.
The changes in the installation database can be used to encapsulate various customizations of a base package required by different groups of users. For example, in organizations where the sales and technical support departments require different installations of a product, the product's base package can be made available to everyone at one administrative installation point. The appropriate customizations are distributed to each group of users separately as transforms. Administrators can apply multiple transforms on-the-fly during an installation to assign the most appropriate installation to different users.
There are three types of transforms:
These are stored inside the .msi file of the package. This way users are guaranteed that the transform is always available when the installation package is available.
Alternatively, transforms may be provided to users as stand-alone .mst files.
Embedded transforms should be prefixed with a : symbol in the transforms list (for example, :mytransform.mst).
These are stored locally on the user's computer in a location where the user does not have write access (sometimes necessary for security reasons). Secured transforms are cached in this location during the installation or advertisement of the package. During subsequent installation-on-demand or maintenance installations of the package, the installer uses the cached transforms.
The removal of the product, by any user, removes all secured transforms for that product from the user's computer.
To specify secured transform storage, set the TransformsSecure policy, or pass the @ (at source) or | (full path) symbol in the transforms list. At source means that the transform is at the root, that is, at the same place as the .msi file.
Transforms that have not been secured, as described in Secured Transforms, are unsecured transforms by default.
The installer saves unsecured transforms in the Application Data folder in each user's profile when the package is installed or advertised. This enables a user to maintain their customization of a product while moving between computers. The transforms are saved in a location to which the user can have write access.
The TRANSFORMS property is a list of the transforms that the Windows Installer applies when installing the package. The installer applies the transforms in the same order as they are listed in the property. Transforms can be specified by their filename or full path. To specify multiple transforms, separate each file name or full path with a semicolon (;).
The installer requires the transforms listed in TRANSFORMS at every installation, advertisement, installation-on-demand, or maintenance installation of the package. See also the Transforms property.
Transforms (.mst files) in the package root will be copied to the administrative installation location, when the administrative installation is performed.
When a transform is applied, its effects may be displayed when you reach the Feature Selection dialog, by either adding to, or subtracting from, the feature list.
|
Copyright © 2013 CA.
All rights reserved.
|
|