Frontend Administration with IModelApp

An instance of IModelApp provides the services needed by the frontend in an interactive iTwin.js app. Services include:

• Connecting to an IModelHost to access iModels.
• Management of Views using ViewManager
• Tools and Drawing aids
• Access to iModelHub using IModelClient
• Notifications
• Localization support
• User settings using Settings

IModelApp Specializations

To support the various use cases and platforms for iTwin.js frontends, there are specialized "apps" that should be used where appropriate.

For a given frontend, you will pick one class from the following list, and call its startup method. The type of IModelApp should match the type of IModelHost running on your backend.

• IModelApp: must always be initialized. For RPC, connects to previously-initialized IModelHost(s) through routing.
  • WebViewerApp: frontend of web viewing apps. May only open iModels readonly, and may not use Ipc. WebViewerApp.startup calls IModelApp.startup.
  • IpcApp: for frontends with a dedicated IpcHost backend. IpcApp.startup calls IModelApp.startup. IpcApp is abstract and should not be used directly.
    • WebEditApp: for the frontend of web editing apps connected to a WebEditHost backend. WebEditApp.startup calls IpcApp.startup and must supply the user's credentials.
    • ElectronApp: for the frontend of desktop apps running on Windows, Mac, or Linux connected to an ElectronHost backend. ElectronApp.startup calls IpcApp.startup.
    • MobileApp: for the frontend of mobile apps. MobileApp.startup calls IpcApp.startup. MobileApp is abstract and should not be used directly.
      • IOSApp: for the frontend of iOS apps. IOSApp.startup calls MobileApp.startup.
      • AndroidApp: for the frontend of Android apps. AndroidApp.startup calls MobileApp.startup.

Applications may customize the behavior of the IModelApp services by providing IModelAppOptions.

Last Updated: 12 June, 2024