The FeatureRequestState property is a read-write property of the Session object. It can be used to obtain the current action state of a feature or to request a change in the action of a feature and its subfeatures. The feature must be named in the Feature table. If a change to the action state of a feature is requested, the action state of all components of the changed feature may be changed as well. The action state of components shared by more than one feature will be changed as appropriate based on the new feature action state (see Remarks). The FeatureRequestState property can also be used to configure all features at once by specifying the keyword ALL instead of a specific feature name.

Syntax

Script
Session.FeatureRequestState

Remarks

The SetInstallLevel method must be called before calling FeatureRequestState.

If the current state of the feature is being requested, the FeatureRequestState property returns one of the following values.

For example, the following obtains the current state of "MyFeature" from a VBScript custom action.

Dim iRequestState
iRequestState = Session.FeatureRequestState("MyFeature")

If the state of the feature is being configured, the FeatureRequestState property should be set to one of the following values.

For example, the following requests from a VBScript custom action that "MyFeature" be installed to run locally on the computer.

Session.FeatureRequestState("MyFeature")=3

When FeatureRequestState is called, the installer attempts to set the action state of each component tied to the specified feature to the specified state, as best as possible. However, there are common situations when the request cannot be fully honored. For example, if a feature is tied to two components, Component A and Component B, through the FeatureComponents table and Component A has the msidbComponentAttributesLocalOnly attribute and component B has the msidbComponentAttributesSourceOnly attribute. In this case, if FeatureRequestState is called with a requested state of either msiInstallStateLocal or msiInstallStateSource, the request cannot be honored for both components. In this case, both components can be turned on with Component A set to msiInstallStateLocal and Component B set to msiInstallStateSource.

If more than one feature is linked to a single component, the final action state of that component is determined as follows: If at least one feature calls for the component to be installed locally, it is installed msiInstallStateLocal. If at least one feature calls for the component to be run from the source media, it is installed msiInstallStateSource. If at least one feature calls for the removal of the component, the action state is msiInstallStateAbsent. For more information on how features are selected for installation, see the Feature table.

If the property fails, you can obtain extended error information by using the LastErrorRecord method.

Requirements

See Also

Session

Feature

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Build date: 8/13/2009