How to set an installer property using custom actions

1.1 Access properties in Immediate custom actions

// getting a property value
string myProperty = "MY_PROPERTY";
string myPropertyValue = session.GetProperty(myProperty);

// setting a property value
session.SetProperty(myProperty, myPropertyValue);
      

1.2 Access properties in Deferred, Rollback or Commit custom actions through the CustomActionData property

Pass properties in the custom action throgu the Action data field that will set the CustomActionData property. When passing multiple properties, you need to add a separator character e.g. ; and for properties that might contain spaces, they need to be enclosed in quotes, as below:

The "|" character is reserved and should not be used as a separator in the ActionData field. Feel free to choose an alternative character for separating properties e.g. ";".

In the custom action, you can have something like this to access the ActionData property:

string customActionData = session.CustomActionData.ToString();

// Split the ActionData string using ';' as the delimiter
string[] parameters = customActionData.Split(';');

// Assign each value to a local variable
string appDir = parameters[0].Trim();        // Expected to be "[APPDIR]"
string productName = parameters[1].Trim();     // Expected to be "[ProductName]"
string productVersion = parameters[2].Trim();  // Expected to be [ProductVersion]

// Optionally, remove the surrounding quotes if necessary
appDir = appDir.Trim('"');
productName = productName.Trim('"');
productVersion = productVersion.Trim('"');

// Display an informative MessageBox for debugging purposes:
System.Windows.Forms.MessageBox.Show(msiWindow, productName + " with version:" + productVersion + " will be installed in the following location: " + appDir, "Info");       
      

You cannot set installer properties from a deferred, rollback or commit custom action, only within an immediate custom action you can set an installer property.

To create a .NET custom action, first install the Advanced Installer extension in Visual Studio (VS). This will add specific project templates to VS you can use to create a C# Custom Action. After creating your dll, you can easily integrate it in your installer project. To do this, use the predefined Call method from .Net assembly custom action to call a function within your dll. For additional guidance, please refer to the How to create a .NET Custom Action article.

2.1 Access properties in Immediate custom actions

// getting a property
MyVariable = session["MyProperty"];

// setting a property
session["MyProperty"] = "MyValue";
      

Check the Retrieving and setting properties in immediate custom actions article for details on how to access installer properties in immediate custom action.

2.2 Access properties in Deferred, Rollback or Commit custom actions through the CustomActionData property

Check the Pass installer properties in deferred custom action to see how to have access to installer properties in a deferred, rollback or commit custom action.

To call a function from a dll, you can use the predefined Call function from attached native DLL custom action. For details, please check the Options to integrate and debug custom actions article with related information for hints and guidance.

3.1 Access properties in Immediate custom actions

# getting a property
$propValue = AI_GetMsiProperty MY_MSI_PROP

# setting a property
AI_SetMsiProperty MY_MSI_PROP "MyValue"
      

3.2 Access properties in Deferred, Rollback or Commit custom actions through script parameters

This can be done through the Script Parameters' field, as follow:

-appdir "[APPDIR]" -productName "[ProductName]" -productVersion [ProductVersion]
      

APPDIR, ProductName and ProductVersion are MSI installer properties. Their values will be assigned to the $appdir, $productName and $productVersion parameters in the PowerShell script. You need to update the Param() block of the script, which must be on the first line, as follows:

Param($appdir, $productName, $productVersion)