Rewrite CampusNet as a class

Modules and Semester are loaded once on first access, then saved.
There's an issue with umlauts, needs to be fixed.

Author: frereit

.gitignore

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+venv

CampusNet.py

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+import sys
+from typing import Union
+from dataclasses import dataclass
+import requests
+from bs4 import BeautifulSoup
+
+
+class LoginError(ValueError):
+    pass
+
+
+@dataclass
+class Module:
+    num: str
+    name: str
+    credits: float
+    status: str
+    semester: str
+    id: str
+    grade: Union[float, None] = None
+
+@dataclass
+class Exam:
+    semester: str
+    description: str
+    grade: Union[float, None] = None
+
+class CampusNetSession:
+    def __init__(self, username: str = None, password: str = None, base_url="https://dualis.dhbw.de/"):
+        """
+        Initialize a new CampusNetSession.
+        :param username: The username of the user.
+        :param password: The password of the user.
+        :raises:
+            ValueError: If the username or password is empty.
+            LoginError: If the login failed.
+        """
+        self.username = username
+        self.password = password
+        self.base_url = base_url
+        self._semesters = None
+        self._modules = None
+        if self.username is None:
+            raise ValueError("Username is empty.")
+        if self.password is None:
+            raise ValueError("Password is empty.")
+        self.session = requests.Session()
+        self._login()
+
+    @property
+    def mgrqispi(self):
+        if self.base_url.endswith("/"):
+            return self.base_url + "scripts/mgrqispi.dll"
+        else:
+            return self.base_url + "/scripts/mgrqispi.dll"
+
+    """
+    ```javascript
+    >>> reloadpage.createUrlAndReload.toString()
+    function(dispatcher, applicationName, programName, sessionNo, menuId,args){
+        [...]
+		window.location.href = dispatcher + \"?APPNAME=\" + applicationName + \"&PRGNAME=\" + programName + \"&ARGUMENTS=-N\" + sessionNo + \",-N\" + menuId  + temp_args;
+	}
+    ```
+    """
+
+    def create_url(self, program_name, args="", application_name="CampusNet"):
+        # Note: MenuID is purely visual, so it doesn't matter. Always pass the HOME menu id.
+        return f"{self.mgrqispi}?APPNAME={application_name}&PRGNAME={program_name}&ARGUMENTS=-N{self.session_number},-N00019{args}"
+
+    def _login(self):
+        """
+        Login to the CampusNet.
+        :raises:
+            LoginError: If the login failed.
+        """
+        response = self.session.post(self.mgrqispi, data={
+            'usrname': self.username,
+            'pass': self.password,
+            'APPNAME': 'CampusNet',
+            'PRGNAME': 'LOGINCHECK',
+            'ARGUMENTS': 'clino,usrname,pass,menuno,menu_type,browser,platform',
+            'clino': '000000000000001',
+            'menuno': '000324',
+            'menu_type': 'classic',
+            'browser': '',
+            'platform': '',
+        })
+        if len(response.cookies) == 0:  # We didn't get a session token in response
+            raise LoginError('Login failed.')
+
+        # The header looks like this
+        # 0; URL=/scripts/mgrqispi.dll?APPNAME=CampusNet&PRGNAME=STARTPAGE_DISPATCH&ARGUMENTS=-N954433323189667,-N000019,-N000000000000000
+        # url will be "/scripts/mgrqispi.dll?APPNAME=CampusNet&PRGNAME=STARTPAGE_DISPATCH&ARGUMENTS=-N954433323189667,-N000019,-N000000000000000"
+        # and arguments will be "-N954433323189667,-N000019,-N000000000000000"
+        # 954433323189667 is the session id, 000019 is the menu id and -N000000000000000 are temporary arguments
+        url = "=".join(response.headers["Refresh"].split(";")[
+                       1].strip().split("=")[1:])
+        arguments = url.split("ARGUMENTS=")[1]
+        self.session_number = arguments.split(",")[0][2:]
+
+    def _get_semesters(self):
+        """
+        Get the semesters from the CampusNet.
+        :return: A list of semesters.
+        """
+        response = self.session.get(self.create_url('COURSERESULTS'))
+        soup = BeautifulSoup(response.text, 'html.parser')
+        semesters = {}
+        for semester in soup.find_all('option'):
+            semesters[semester.text] = semester.get('value')
+        return semesters
+
+    @property
+    def semesters(self):
+        """
+        Lazily loads the semesters.
+        :return: A dictionary of all semesters.
+        """
+        if not self._semesters:
+            self._semesters = self._get_semesters()
+        return self._semesters
+
+    def _get_modules(self):
+        """
+        Get the modules from the CampusNet.
+        :return: A list of modules.
+        """
+        modules = []
+        for semester in self.semesters:
+            response = self.session.post(self.mgrqispi, data={
+                'APPNAME': 'CampusNet',
+                'semester': self.semesters[semester],
+                'Refresh': 'Aktualisieren',
+                'PRGNAME': 'COURSERESULTS',
+                'ARGUMENTS': 'sessionno,menuno,semester',
+                'sessionno': self.session_number,
+                'menuno': '000307'
+            })
+
+            soup = BeautifulSoup(response.text, 'html.parser')
+            table = soup.find('table', {'class': 'nb list'})
+            for row in table.find_all('tr')[1:]:
+                cells = row.find_all('td')
+                if len(cells) == 7:
+                    try:
+                        grade = float(cells[2].text.strip().replace(",", "."))
+                    except ValueError:
+                        grade = None
+                    # getting id for this module
+                    exams_button = cells[5]
+                    # FIXME: This is a hack, looking for a specific substring in JavaScript code.
+                    exams_script = exams_button.find('script').text
+                    exams_id = exams_script.split('","Resultdetails"')[0].split(",-N")[-1]
+                    modules.append(Module(
+                        num=cells[0].text.strip(),
+                        name=cells[1].text.strip(),
+                        credits=float(cells[3].text.strip().replace(',', '.')),
+                        status=cells[4].text.strip(),
+                        semester=semester,
+                        id=exams_id,
+                        grade=grade
+                    ))
+                elif len(cells) != 0:
+                    # FIXME: proper logging
+                    print("Unexpected number of cells:",
+                          len(cells), file=sys.stderr)
+        return modules
+
+    @property
+    def modules(self):
+        """
+        Lazily loads the modules.
+        :return: A list of all modules.
+        """
+        if not self._modules:
+            self._modules = self._get_modules()
+        return self._modules
+
+    def get_exams_for_module(self, module: Module):
+        """
+        Get the exams for a module.
+        :param module: The module.
+        :return: A list of exams.
+        """
+        response = self.session.get(self.create_url('RESULTDETAILS', f",-N{module.id}"))
+        soup = BeautifulSoup(response.text, 'html.parser')
+        exam_table = soup.find('table', {'class': 'tb'})
+        exams = []
+        for row in exam_table.find_all("tr"):
+            cells = row.find_all('td')
+            if len(cells) == 6 and all("tbdata" in cell["class"] for cell in cells):
+                try:
+                    grade = float(cells[3].text.strip().replace(",", "."))
+                except ValueError:
+                    grade = None
+                exams.append(Exam(
+                    semester=module.semester,
+                    description=cells[1].text.strip(),
+                    grade=grade,
+                ))
+        return exams

campusnet.py

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+beautifulsoup4==4.11.*
+requests==2.28.*