feat: Add exercises tags

lms/lmsdb/models.py

@@ -346,6 +346,18 @@ def on_notification_saved(
         instance.delete_instance()
 
 
+class ExerciseTagText(BaseModel):
+    text = TextField(unique=True)
+
+    @classmethod
+    def create_tag(cls, text: str) -> 'ExerciseTagText':
+        instance, _ = cls.get_or_create(**{cls.text.name: html.escape(text)})
+        return instance
+
+    def __str__(self):
+        return self.text
+
+
 class Exercise(BaseModel):
     subject = CharField()
     date = DateTimeField()
@@ -378,7 +390,7 @@ def is_number_exists(cls, number: int) -> bool:
     @classmethod
     def get_objects(
         cls, user_id: int, fetch_archived: bool = False,
-        from_all_courses: bool = False,
+        from_all_courses: bool = False, exercise_tag: Optional[str] = None,
     ):
         user = User.get(User.id == user_id)
         exercises = (
@@ -394,6 +406,13 @@ def get_objects(
             exercises = exercises.where(
                 UserCourse.course == user.last_course_viewed,
             )
+        if exercise_tag:
+            exercises = (
+                exercises
+                .join(ExerciseTag)
+                .join(ExerciseTagText)
+                .where(ExerciseTagText.text == exercise_tag)
+            )
         if not fetch_archived:
             exercises = exercises.where(cls.is_archived == False)  # NOQA: E712
         return exercises
@@ -408,6 +427,7 @@ def as_dict(self) -> Dict[str, Any]:
             'exercise_number': self.number,
             'course_id': self.course.id,
             'course_name': self.course.name,
+            'tags': ExerciseTag.by_exercise(self),
         }
 
     @staticmethod
@@ -426,6 +446,36 @@ def exercise_number_save_handler(model_class, instance, created):
         instance.number = model_class.get_highest_number() + 1
 
 
+class ExerciseTag(BaseModel):
+    exercise = ForeignKeyField(Exercise)
+    tag = ForeignKeyField(ExerciseTagText)
+    date = DateTimeField(default=datetime.now)
+
+    @classmethod
+    def by_exercise(
+        cls, exercise: Exercise,
+    ) -> Union[Iterable['ExerciseTag'], 'ExerciseTag']:
+        return (
+            cls
+            .select()
+            .where(cls.exercise == exercise)
+            .order_by(cls.date)
+        )
+
+    @classmethod
+    def is_course_tag_exists(cls, course: Course, tag_name: str):
+        return (
+            cls
+            .select()
+            .join(ExerciseTagText)
+            .where(ExerciseTagText.text == tag_name)
+            .switch()
+            .join(Exercise)
+            .where(Exercise.course == course)
+            .exists()
+        )
+
+
 class SolutionState(enum.Enum):
     CREATED = 'Created'
     IN_CHECKING = 'In checking'
@@ -561,11 +611,11 @@ def test_results(self) -> Iterable[dict]:
     @classmethod
     def of_user(
         cls, user_id: int, with_archived: bool = False,
-        from_all_courses: bool = False,
+        from_all_courses: bool = False, exercise_tag: Optional[str] = None,
     ) -> Iterable[Dict[str, Any]]:
         db_exercises = Exercise.get_objects(
             user_id=user_id, fetch_archived=with_archived,
-            from_all_courses=from_all_courses,
+            from_all_courses=from_all_courses, exercise_tag=exercise_tag,
         )
         exercises = Exercise.as_dicts(db_exercises)
         solutions = (

lms/lmsweb/views.py

@@ -343,16 +343,26 @@ def change_last_course_viewed(course_id: int):
 
 
 @webapp.route('/exercises')
+@webapp.route('/exercises/<tag_name>')
 @login_required
-def exercises_page():
+def exercises_page(tag_name: Optional[str] = None):
     fetch_archived = bool(request.args.get('archived'))
-    exercises = Solution.of_user(current_user.id, fetch_archived)
+    try:
+        solutions.check_tag_name(tag_name)
+    except LmsError as e:
+        error_message, status_code = e.args
+        return fail(status_code, error_message)
+
+    exercises = Solution.of_user(
+        current_user.id, fetch_archived, exercise_tag=tag_name,
+    )
     is_manager = current_user.role.is_manager
     return render_template(
         'exercises.html',
         exercises=exercises,
         is_manager=is_manager,
         fetch_archived=fetch_archived,
+        tag_name=tag_name,
     )
 
 
@@ -479,7 +489,7 @@ def comment():
 
 @webapp.route('/send/<int:course_id>/<int:_exercise_number>')
 @login_required
-def send(course_id: int, _exercise_number: Optional[int]):
+def send(course_id: int, _exercise_number: Optional[int] = None):
     if not UserCourse.is_user_registered(current_user.id, course_id):
         return fail(403, "You aren't allowed to watch this page.")
     return render_template('upload.html', course_id=course_id)

lms/models/solutions.py

@@ -8,7 +8,9 @@
 from playhouse.shortcuts import model_to_dict  # type: ignore
 
 from lms.extractors.base import File
-from lms.lmsdb.models import SharedSolution, Solution, SolutionFile, User
+from lms.lmsdb.models import (
+    ExerciseTag, SharedSolution, Solution, SolutionFile, User,
+)
 from lms.lmstests.public.general import tasks as general_tasks
 from lms.lmstests.public.identical_tests import tasks as identical_tests_tasks
 from lms.lmsweb import config, routes
@@ -205,3 +207,15 @@ def get_files_tree(files: Iterable[SolutionFile]) -> List[Dict[str, Any]]:
     for file in file_details:
         del file['fullpath']
     return file_details
+
+
+def check_tag_name(tag_name: Optional[str]) -> None:
+    if (
+        tag_name is not None and not ExerciseTag.is_course_tag_exists(
+            current_user.last_course_viewed, tag_name,
+        )
+    ):
+        raise ResourceNotFound(
+            f'No such tag {tag_name} for course '
+            f'{current_user.last_course_viewed.name}.', 404,
+        )

lms/static/my.css

@@ -177,6 +177,24 @@ a {
   line-height: 3rem;
 }
 
+.exercise-tags {
+  align-items: center;
+  display: flex;
+  font-size: 1em;
+  height: 3rem;
+  justify-content: center;
+  text-align: center;
+  white-space: normal;
+}
+
+#exercise-tag-link {
+  color: #919191;
+}
+
+#exercise-tag-link:hover {
+  color: #646464;
+}
+
 .exercise-send {
   display: flex;
   flex-direction: row;

lms/templates/exercises.html

@@ -5,7 +5,7 @@
   <div id="exercises-page" class="page {{ direction }}">
     <div id="exercises-header">
       <div id="main-title">
-        <h1 id="exercises-head">{{ _('Exercises') }}</h1>
+        <h1 id="exercises-head">{{ _('Exercises') }}{% if tag_name %} - #{{ tag_name }}{% endif %}</h1>
       </div>
     </div>
     <div id="exercises">
@@ -14,6 +14,11 @@ <h1 id="exercises-head">{{ _('Exercises') }}</h1>
         <div class="right-side {{ direction }}-language">
           <div class="exercise-number me-3">{{ exercise['exercise_number'] }}</div>
           <div class="exercise-name"><div class="ex-title">{{ exercise['exercise_name'] | e }}</div></div>
+          <div class="exercise-tags ms-1">
+            {% for tag in exercise.tags %}
+              <a class="ms-1" id="exercise-tag-link" href="{{ url_for('exercises_page', tag_name=tag.tag) }}">#{{ tag.tag }}</a>
+            {% endfor %}
+          </div>
         </div>
         <div class="left-side">
           <div class="comments-count">

lms/templates/navbar.html

@@ -66,7 +66,7 @@
             </a>
           </li>
         {% endif -%}
-        {%- if not exercises or fetch_archived %}
+        {%- if not exercises or fetch_archived or tag_name %}
         <li class="nav-item">
           <a href="/exercises" class="nav-link">
             <i class="fa fa-book" aria-hidden="true"></i>

tests/conftest.py

@@ -15,8 +15,9 @@
 import pytest
 
 from lms.lmsdb.models import (
-    ALL_MODELS, Comment, CommentText, Course, Exercise, Note, Notification,
-    Role, RoleOptions, SharedSolution, Solution, User, UserCourse,
+    ALL_MODELS, Comment, CommentText, Course, Exercise, ExerciseTag,
+    ExerciseTagText, Note, Notification, Role, RoleOptions, SharedSolution,
+    Solution, User, UserCourse,
 )
 from lms.extractors.base import File
 from lms.lmstests.public import celery_app as public_app
@@ -308,14 +309,19 @@ def create_exercise(
     )
 
 
+def create_exercise_tag(tag_text: str, exercise: Exercise):
+    new_tag_id = ExerciseTagText.create_tag(text=tag_text).id
+    return ExerciseTag.create(exercise=exercise, tag=new_tag_id)
+
+
 def create_shared_solution(solution: Solution) -> SharedSolution:
     return SharedSolution.create_new(solution=solution)
 
 
 def create_note(
     creator: User,
     user: User,
-    note_text: CommentText,
+    note_text: str,
     privacy: int,
 ):
     new_note_id = CommentText.create_comment(text=note_text).id

tests/test_exercises.py

@@ -52,3 +52,28 @@ def test_courses_exercises(
         template, _ = captured_templates[-1]
         assert template.name == 'exercises.html'
         assert len(list(Exercise.get_objects(student_user.id))) == 2
+
+    @staticmethod
+    def test_exercise_tags(
+        student_user: User, course: Course, exercise: Exercise,
+    ):
+        client = conftest.get_logged_user(username=student_user.username)
+        conftest.create_usercourse(student_user, course)
+        client.get(f'course/{course.id}')
+        conftest.create_exercise_tag('tag1', exercise)
+        tag_response = client.get('/exercises/tag1')
+        assert tag_response.status_code == 200
+
+        course2 = conftest.create_course(index=1)
+        exercise2 = conftest.create_exercise(course2, 2)
+        conftest.create_usercourse(student_user, course2)
+        conftest.create_exercise_tag('tag2', exercise2)
+        bad_tag_response = client.get('/exercises/tag2')
+        assert bad_tag_response.status_code == 404
+
+        client.get(f'course/{course2.id}')
+        success_tag_response = client.get('/exercises/tag2')
+        assert success_tag_response.status_code == 200
+
+        another_bad_tag_response = client.get('/exercises/wrongtag')
+        assert another_bad_tag_response.status_code == 404