Setup App to load Extensions

By default, every IModelApp has the ExtensionAdmin configured to use the Bentley Extension Service. However, additional endpoints can be configured by adding an ExtensionLoader to the ExtensionAdmin with ExtensionAdmin.addExtensionLoader or providing a different instance of the ExtensionAdmin to IModelApp.startup.

There are two ExtensionLoaders provided, one, ExtensionServiceExtensionLoader, for connecting to the Bentley Extension Service, and the second, ExternalServerExtensionLoader, for using a different URL scheme for pulling the Extensions. The second one is most commonly used for deploying an Extension locally to debug.

Loading Extensions

An Extension is loaded into an app by calling the ExtensionAdmin.loadExtension static method, which uses the current IModelApp.extensionAdmin session to load the provided extension.

The Extension is loaded using the HTML script tag, making any code within the javascript module immediately executed.

By convention, an Extension creates an instance of itself and registers the new instance with the host app, using IModelApp.extensionAdmin.register, in the top-level scope. This is the first step required in properly loading and allows IModelApp to know the request to loadExtension has succeeded and the Extension is now ready for the onLoad method to be executed.

Other ways to load an Extension

An ImmediateTool is, by default, provided in every IModelApp which supports a user to initiate the Extension loading process using the Extension \<ExtensionName\> [argument list] keyin.

Last Updated: 01 December, 2021