Welcome to the next step in our journey of building a personal tutor service with DeepSeek models. In the previous lesson, we explored the TutorService
class, which acts as a bridge between managing tutoring session data and generating AI responses. Now, we will focus on the TutorController, a crucial component that manages tutoring sessions and handles student queries by interacting with both the model and service layers. The controller is responsible for orchestrating the flow of data between the student interface and the backend services, ensuring that student interactions are processed efficiently and effectively.
The TutorController
class is the heart of our controller layer. It is responsible for managing tutoring sessions and processing student queries. Let's begin by examining the structure of the TutorController
class in JavaScript.
In this snippet, we:
- Import the Node.js built-in
crypto
library for generating unique identifiers. - Import the
TutorService
class for managing tutoring data and processing student queries. - Initialize the
TutorController
with an instance ofTutorService
. - Create a
testSession
object to simulate session management for testing purposes.
The testSession
object is a simple in-memory store used to simulate session management for testing. It allows us to mimic the behavior of student sessions typically managed by a web application or browser. In a real-world scenario, student sessions help track individual students as they interact with a web application, maintaining their state and data across multiple requests. By using testSession
, we can focus on testing the core functionality of the TutorController
without needing a full session management system. Once we are confident that the controller works correctly, we will later integrate a more robust session management solution when developing our RESTful API.
Before creating a tutoring session, we need to ensure that a student session exists. The ensureStudentSession
method checks if a student ID is present in the testSession
. If not, it generates a new student ID.
This method ensures that a student session is available by checking the testSession
object for a studentId
. If it doesn't exist, a new student ID is generated using crypto.randomUUID()
and stored in the session. The method then returns the student ID, either the newly created one or the existing one.
One of the primary responsibilities of the TutorController
is to create new tutoring sessions. The createSession
method handles session creation requests.
In this method, we:
-
Retrieve the
studentId
: We first check thetestSession
for astudentId
. -
Handle Session Expiry: If the session has expired (i.e., no
studentId
is found), we return an error response using our helper method_errorResponse
with a 401 status code, which we will discuss later. This approach ensures that the client can handle the error gracefully, providing a better user experience. -
Create a Tutoring Session: If the session is valid, we call the
createSession
method of theTutorService
with the student ID to create a new tutoring session. We then return a success response containing a unique session ID and a success message using our helper method_successResponse
, which we will discuss later.
The sendQuery
method is responsible for processing student queries and returning the tutor's response or an error message.
In this method:
-
We first check if the student session is valid by retrieving the
studentId
from thetestSession
. If nostudentId
is found, we return an error response with a 401 status code. -
We then validate that both
sessionId
andstudentQuery
are provided. If either is missing, we return an error response with a 400 status code. -
If all validations pass, we attempt to process the query using the
processQuery
method of theTutorService
. This method takes thestudentId
,sessionId
, andstudentQuery
as parameters. Since this is an asynchronous operation, we useawait
. -
If the query is processed successfully, we return the tutor's response in a success response format.
-
If a
ValueError
occurs (e.g., if the session ID doesn't exist), we return an error response with a 404 status code. -
If a
RuntimeError
occurs (e.g., if there's an issue with the AI model), we return an error response with a 500 status code. -
For any other unexpected errors, we return a generic error response with a 500 status code.
The TutorController
includes two helper methods for formatting responses: _successResponse
and _errorResponse
. These methods ensure consistent response formats throughout the controller.
These methods create standardized response formats:
_successResponse
returns an object with astatus
field set to"success"
and adata
field containing the provided data._errorResponse
returns an object with astatus
field set to"error"
and anerror
field with message and code details.
Unlike the Python version, we do not return tuples. Instead, the error response object includes the status code as part of the error details, which is a common convention in JavaScript applications.
To see the TutorController
in action, let's integrate it into the main application. This example demonstrates how to create a tutoring session and handle a student query, showcasing the controller's functionality.
In this example, we first initialize the TutorController
. We ensure a student session is available for testing. We then create a new tutoring session and handle the response. If successful, we simulate a student query about the differences between mitosis and meiosis and use the sendQuery
method to process it. The response is checked for errors, and either the error message or the tutor's response is printed. This example demonstrates the flow from ensuring a student session to creating a tutoring session and handling a student query, highlighting the controller's role in managing interactions.
In this lesson, we explored the TutorController
class and its role in managing tutoring sessions and handling student queries. We learned how to implement the controller, create tutoring sessions, and process student questions using the TutorService
. The controller is a vital component of our personal tutor application, ensuring that student interactions are managed efficiently and effectively.
As you move on to the practice exercises, take the opportunity to experiment with the TutorController
's functionality. This hands-on practice will reinforce the concepts covered in this lesson and prepare you for the next steps in our course. Keep up the great work, and I look forward to seeing your progress!
