Initialize data before app is loaded

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The App.onBeforeAppReady hook allows you to execute custom logic before the application User Interface (UI) is initialized and rendered.

When this hook executes, only platform-initialized data is available, including:

• Application-level variables
• Platform metadata, such as:
  • Security configuration
  • Logged-in user context (if authentication is enabled)

This makes it an ideal place to perform pre-initialization logic, such as:

• Setting the application UI mode based on user preferences
• Loading organization-specific configurations
• Redirecting users based on roles or permissions
• Blocking app load with a custom error or maintenance screen if a check fails

Execution Timing

This hook is executed before the application UI is initialized, equivalent to Angular’s appInitialization provider.

As a result:

• The application waits for this hook to complete before continuing startup.
• If the hook returns a Promise:
  • The application waits for the Promise to resolve before proceeding.
  • Application initialization stops if the Promise rejects or an error is thrown.

Example

Use case: Setting UI color mode based on the Logged-in User preferences.

// add the hook in app.js
App.onBeforeAppReady = function () {
    // Check if the user is authenticated
    if (App.Variables.loggedInUser?.dataSet?.isAuthenticated) {
        var userId = App.Variables.loggedInUser.dataSet.id;
        App.Variables.getUserData.setInput('userId', userId);

        return App.Variables.getUserData.invoke().then((res) => {
            let userData = JSON.parse(res.body);

            // Apply user-specific theme
            App.setMode({ color: userData.__theme });
        }).catch((err) => {
            console.error("Failed to load user theme:", err);
            App.Actions.navigateToPage('errorPage');
            return Promise.reject(err);
        });
    }
};

Points to Remember

• Return a Promise when performing asynchronous operations (such as API calls or database queries).
• If the Promise is rejected or an error is thrown, application initialization stops. This can be used to enforce controlled startup failures (for example, invalid sessions or maintenance mode).
• Keep logic minimal and efficient to avoid delaying application startup.
• You can use any available App variables safely inside this hook.