Changing a student's topic does not work

[Schlaumeier5]

If you try to change a student's topic in the student dashboard (when logged in as teacher or admin), the server will send back an error 500.
Following error log:

java.lang.ClassCastException: class java.lang.String cannot be cast to class java.lang.Number (java.lang.String and java.lang.Number are in module java.base of loader 'bootstrap')
        at de.igslandstuhl.database.server.webserver.requests.PostRequest.getInt(PostRequest.java:152)
        at de.igslandstuhl.database.server.webserver.requests.APIPostRequest.getTopic(APIPostRequest.java:56)
        at de.igslandstuhl.database.server.webserver.handlers.PostRequestHandler.lambda$registerHandlers$15(PostRequestHandler.java:261)
        at de.igslandstuhl.database.server.webserver.handlers.HttpHandler.handleHttpRequest(HttpHandler.java:38)
        at de.igslandstuhl.database.server.webserver.handlers.PostRequestHandler.handlePostRequest(PostRequestHandler.java:86)
        at de.igslandstuhl.database.server.WebServer$ClientHandler.handlePost(WebServer.java:149)
        at de.igslandstuhl.database.server.WebServer$ClientHandler.run(WebServer.java:103)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
        at java.base/java.lang.Thread.run(Thread.java:840)

The error is thrown in the following line:

student-database/src/main/java/de/igslandstuhl/database/server/webserver/handlers/PostRequestHandler.java

Line 261 in ce60199

Topic topic = rq.getTopic();

(whole handler:

student-database/src/main/java/de/igslandstuhl/database/server/webserver/handlers/PostRequestHandler.java

Lines 257 to 265 in ce60199

	HttpHandler.registerPostRequestHandler("/change-current-topic", AccessLevel.TEACHER, (rq) -> {
	Student student = rq.getCurrentStudent();
	if (student == null) return PostResponse.unauthorized(rq);
	Subject subject = rq.getSubject();
	Topic topic = rq.getTopic();
	if (subject == null || topic == null) return PostResponse.badRequest("Subject or topic id not found", rq);
	student.setCurrentTopic(subject, topic);
	return PostResponse.ok("Current topic changed successfully", ContentType.TEXT_PLAIN, rq);
	});

)
Probably the issue is that the handler expects the topic id (as a number) but it is either given the topic name or the topic id as string.
This is the relevant code in the front end:

student-database/src/main/resources/js/site/student-database.js

Lines 663 to 673 in ce60199

	const topicSelect = document.createElement('select');
	topicSelect.id = "topicSelect";
	populateTopicSelect(topicSelect, subject.id, studentData.schoolClass.grade, topic);
	topicSelect.addEventListener('change', async e => {
	result = await changeCurrentTopic(studentId, subject.id, topicSelect.value);
	if (result.ok) {
	panel.refresh();
	} else {
	alert('Fehler beim Ändern des Themas')
	}
	});

[g17dev]

👋 Hi! I’d like to work on this issue if no one else is currently assigned.
This would be my first contribution to Learn-Monitor, but I have intermediate Java experience.
Please let me know if there’s any guidance or preferred approach before I start. Thanks!

[Schlaumeier5]

👋 Hi! I’d like to work on this issue if no one else is currently assigned.
This would be my first contribution to Learn-Monitor, but I have intermediate Java experience.
Please let me know if there’s any guidance or preferred approach before I start. Thanks!

You can work on this, if you want, nice to have you here 🫶
It's not much you need to do here, just run the server and test what the client is sending in the request, then change it to the actual topic id instead of the string.
If you need any instructions for setting your environment up for debugging lmk
I will assign you to this then

[g17dev]

It's a pleasure to help 🫡, your assistance in setting up the environment would be very helpful, please.

[Schlaumeier5]

@g17dev
You can import it in your favorite ide as gradle project.
Then the main class is de.igslandstuhl.database.Application, you can also run the fat jar in build/libs after running the gradle build task.
You will have to set up a keystore for the https server, you can do this using java keytool: (run this in your environment folder)

keytool -genkey -keyalg RSA -keystore keys/web/keystore.jks -storetype JKS

Unzip the following test database and put it in your environment folder:
database.zip
It's a simple test database.
After that, you can just run the application, for the prompts at the start, you can just press enter for standard prompts.
It will open an https server at localhost:443, use the user "adminUser" and the password "adminPass".
To repoduce the error, click on "students" and then view any student, open a topic and try to change it using the select fields.

[Schlaumeier5]

@g17dev how is it going?

[g17dev]

Sorry bro, I was a bit busy yesterday and couldn't make any progress. I tried what you mentioned, but I'm still having problems. When I run the program, these options appear. I fill them in as follows, and that's all that happens. Nothing else appears. Why is that?

[Schlaumeier5]

@g17dev it opens a https server on port 443, you can access the frontend with your browser

[g17dev]

I've already logged in, I'll check the change and if you like, I can also add a message when running the executable because it's a little confusing to know if it's working.

[Schlaumeier5]

@g17dev sure, but if you change other things, please put them in the commit message

[Schlaumeier5]

@g17dev how is it going?

[Schlaumeier5]

@g17dev let me know if you are still onto this, we kinda need this until tomorrow, it's fine if you don't want to do it, just tell me