In MVC architecture, the Controller component is responsible for handling user interactions and managing the flow of data between the Model and View.

Integrating with an external WebSocket API in AngularJS is advantageous because it reduces the need for constant polling. WebSockets enable bidirectional communication between the client and server, allowing real-time data updates. This leads to a more responsive and efficient application, particularly in scenarios where timely updates are critical, such as live chat applications or financial dashboards.

The primary purpose of AngularJS expressions is to bind data from the model to the view. These expressions are written in double curly braces {{ }} and are used to display dynamic data in the HTML document. By using expressions, AngularJS allows developers to create dynamic and responsive user interfaces, making it easier to reflect changes in the underlying data in real-time. Understanding expressions is fundamental for effective data binding in AngularJS applications.

The process of data binding in a controller when using AngularJS directives typically involves one-way binding from the controller to the view. Directives can manipulate the DOM based on the data in the controller, and changes in the controller are reflected in the view. This unidirectional flow helps maintain a clear separation of concerns and enables a more predictable and manageable data binding process in AngularJS applications.

The primary purpose of a module in AngularJS is encapsulating components. Modules help organize and structure an AngularJS application by grouping related components, services, and directives together. This encapsulation enhances modularity, maintainability, and code reusability in AngularJS projects. Understanding the role of modules is fundamental for creating well-organized and scalable AngularJS applications.

AngularJS expressions can be leveraged in a complex application for dynamic content rendering through various techniques. Using ng-repeat allows developers to iterate over a collection and generate dynamic content on the fly. Embedding expressions in custom directives enables the creation of reusable components with dynamic behavior. Additionally, utilizing expressions in routing configurations allows for dynamic page rendering based on user interactions. A comprehensive understanding of these approaches is essential for building scalable and dynamic AngularJS applications.

The ng-click directive in AngularJS is used to execute a function in the controller when a specified event (such as a button click) occurs. This directive binds the specified expression to the click event, allowing developers to define custom behaviors when the associated element is clicked. Understanding how to use ng-click is essential for handling user interactions in AngularJS applications.

The ng-model directive in AngularJS creates a two-way binding between the model and the view. This means that changes in the model automatically update the view, and vice versa. It is commonly used in forms to handle user input and keep the model and view in sync. Understanding ng-model is crucial for building interactive and responsive user interfaces in AngularJS applications.

To avoid polluting the global scope, controllers should be encapsulated within a module. Modules in AngularJS act as containers for different components of an application, providing a way to organize and structure the code. Encapsulating controllers within modules helps in managing dependencies, improving code maintainability, and preventing naming conflicts in large applications.

Deep watching an object in AngularJS for data binding in a controller can have implications on performance. Deep watching involves monitoring changes at nested levels within an object, and if not used judiciously, it can lead to performance issues by triggering frequent digest cycles. Developers need to be cautious when employing deep watches to avoid unnecessary overhead in complex applications.