Fix part of #19435: Migrate the Subtopic Viewer Page to Angular

[Lawful2002]

Overview

1. This PR fixes part of Migration of Individual Pages from Webpack/AngularJS to Lazy-Loaded Angular Modules #19435.
2. This PR does the following: Migrates the subtopic viewer page to Angular.

Essential Checklist

Please follow the instructions for making a code change.

• I have linked the issue that this PR fixes in the "Development" section of the sidebar.
• I have checked the "Files Changed" tab and confirmed that the changes are what I want to make.
• I have written tests for my code.
• The PR title starts with "Fix #bugnum: " or "Fix part of #bugnum: ...", followed by a short, clear summary of the changes.
• I have assigned the correct reviewers to this PR (or will leave a comment with the phrase "@{{reviewer_username}} PTAL" if I can't assign them directly).

Proof that changes are correct

The server is running and we are able to access the Subtopic Viewer page without any console errors.

Logged In:

Logged out:

Video:
Screencast from 17-05-24 12:14:21 AM IST.webm

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[oppiabot]

Hi @Lawful2002, can you complete the following:

1. The body of this PR is missing the required description, please update the body with a description of what this PR does.
   Thanks!

[oppiabot]

Hi @Lawful2002 please assign the required reviewer(s) for this PR. Thanks!

[Lawful2002]

I also tried this:
`class SubtopicViewerPageAccessValidator(
base.BaseHandler[Dict[str, str], Dict[str, str]]
):
""" Validates access to the Subtopic Viewer Page """

GET_HANDLER_ERROR_RETURN_TYPE = feconf.HANDLER_TYPE_JSON
URL_PATH_ARGS_SCHEMAS = {
    'classroom_url_fragment': constants.SCHEMA_FOR_CLASSROOM_URL_FRAGMENTS,
    'topic_url_fragment': constants.SCHEMA_FOR_TOPIC_URL_FRAGMENTS,
    'subtopic_url_fragment': {
        'schema': {
            'type': 'basestring',
            'validators': [{
                'id': 'is_regex_matched',
                'regex_pattern': constants.VALID_URL_FRAGMENT_REGEX
            }, {
                'id': 'has_length_at_most',
                'max_value': constants.MAX_CHARS_IN_SUBTOPIC_URL_FRAGMENT
            }]
        }
    }
}
HANDLER_ARGS_SCHEMAS: Dict[str, Dict[str, str]] = {'GET': {
    'classroom_url_fragment': constants.SCHEMA_FOR_CLASSROOM_URL_FRAGMENTS,
    'topic_url_fragment': constants.SCHEMA_FOR_TOPIC_URL_FRAGMENTS,
    'subtopic_url_fragment': {
        'schema': {
            'type': 'basestring',
            'validators': [{
                'id': 'is_regex_matched',
                'regex_pattern': constants.VALID_URL_FRAGMENT_REGEX
            }, {
                'id': 'has_length_at_most',
                'max_value': constants.MAX_CHARS_IN_SUBTOPIC_URL_FRAGMENT
            }]
        }
    }
}}

@acl_decorators.open_access
def get(self, classroom_url_fragment: str, topic_url_fragment: str, subtopic_url_fragment: str) -> None:
    """ Handles GET requests """
    topic = topic_fetchers.get_topic_by_url_fragment(topic_url_fragment)
    if not topic:
        raise self.NotFoundException
    
    user_actions_info = user_services.get_user_actions_info(self.user_id)
    topic_rights = topic_fetchers.get_topic_rights(topic.id)

    if ((topic_rights is None or not topic_rights.topic_is_published) and
        role_services.ACTION_VISIT_ANY_TOPIC_EDITOR_PAGE not in user_actions_info.actions):
        raise self.NotFoundException
    
    subtopic_id = None
    for subtopic in topic.subtopics:
        if subtopic.url_fragment == subtopic_url_fragment:
            subtopic_id = subtopic.id

    if not subtopic_id:
        raise self.NotFoundException
    
    verified_classroom_url_fragment = (
        classroom_config_services.get_classroom_url_fragment_for_topic_id(
            topic.id))
    if classroom_url_fragment != verified_classroom_url_fragment:
        raise self.NotFoundException
    
    subtopic_page = subtopic_page_services.get_subtopic_page_by_id(
        topic.id, subtopic_id, strict=False)
    if subtopic_page is None:
        raise self.NotFoundException`

Didn't help

[oppiabot]

Hi @Lawful2002. Due to recent changes in the "develop" branch, this PR now has a merge conflict. Please follow this link if you need help resolving the conflict, so that the PR can be merged. Thanks!

[seanlip]

this isn't calling self.render_json() like other GET JSON handlers do; could that be the issue?

[Lawful2002]

Actually in the SubtopicViewer, there is a data handler calling a render_json

[seanlip]

Sorry, I don't understand. All GET JSON handlers end with self.render_json({something}) -- why doesn't this one do so?

[Nik-09]

Sorry @Lawful2002 for the delay. I will take a look tomorrow morning. Thank you