// ============================================================
// LEARNING HUB — User content feed, viewer, quizzes + Admin CMS
// ============================================================
(function() {
var loaded = false;
var cmsLoaded = false;
var currentContent = null;
var currentView = 'feed'; // 'feed' | 'category' | 'viewer'
// ── Load when tab activated ────────────────────────────────
document.addEventListener('tabChanged', function(e) {
if (e.detail && e.detail.tab === 'learning') {
if (!loaded) { loadFeed(); loadCategories(); loaded = true; }
}
// Load CMS when Content Manager tab is opened
if (e.detail && e.detail.tab === 'cms') {
if (!cmsLoaded) { loadCms(); cmsLoaded = true; }
}
});
// ── Event delegation ───────────────────────────────────────
document.addEventListener('click', function(e) {
// Feed item click
var feedItem = e.target.closest('.lh-feed-item');
if (feedItem && feedItem.dataset.slug) {
loadContent(feedItem.dataset.slug);
return;
}
// Category pill click
var catPill = e.target.closest('.lh-cat-pill');
if (catPill && catPill.dataset.slug) {
if (catPill.dataset.slug === 'all') {
loadFeed();
setActiveCatPill('all');
} else {
loadCategoryContent(catPill.dataset.slug);
setActiveCatPill(catPill.dataset.slug);
}
return;
}
// Back button
if (e.target.closest('#lh-back')) {
showFeed();
return;
}
// Submit quiz
if (e.target.closest('#lh-submit-quiz')) {
submitQuiz();
return;
}
// ── CMS events ─────────────────────────────
if (e.target.closest('#btn-lh-add-cat')) { addCategory(); return; }
if (e.target.closest('#btn-lh-new-content')) { openEditor(null, 'article'); return; }
if (e.target.closest('#btn-lh-new-quiz')) { openEditor(null, 'quiz'); return; }
if (e.target.closest('#btn-lh-new-pearl')) { openEditor(null, 'pearl'); return; }
if (e.target.closest('#btn-lh-close-editor')) { closeEditor(); return; }
if (e.target.closest('#btn-lh-save-content')) { saveContent(); return; }
if (e.target.closest('#btn-lh-delete-content')) { deleteContent(); return; }
if (e.target.closest('#btn-lh-add-question')) { addQuestionBlock(); return; }
// Editor toolbar buttons
var tbBtn = e.target.closest('.cms-tb-btn');
if (tbBtn && tbBtn.dataset.insert) { insertTag(tbBtn.dataset.insert); return; }
// CMS content item edit
var cmsItem = e.target.closest('.lh-cms-content-item');
if (cmsItem && cmsItem.dataset.id) { openEditor(cmsItem.dataset.id); return; }
// CMS delete category
var delCat = e.target.closest('.lh-cms-del-cat');
if (delCat) { deleteCategory(delCat.dataset.id); return; }
// Remove question block
var rmQ = e.target.closest('.lh-rm-question');
if (rmQ) { var qb = rmQ.closest('.lh-question-block'); if (qb) qb.remove(); return; }
// Add option to question
var addOpt = e.target.closest('.lh-add-option');
if (addOpt) {
var qBlock = addOpt.closest('.lh-question-block');
if (qBlock) addOptionRow(qBlock.querySelector('.lh-options-list'), null);
return;
}
// Remove option
var rmOpt = e.target.closest('.lh-rm-option');
if (rmOpt) { var row = rmOpt.closest('.lh-option-row'); if (row) row.remove(); return; }
});
// Search
var searchTimeout = null;
var searchEl = document.getElementById('lh-search');
if (searchEl) {
searchEl.addEventListener('input', function() {
clearTimeout(searchTimeout);
var q = searchEl.value.trim();
if (!q) { loadFeed(); return; }
searchTimeout = setTimeout(function() { searchContent(q); }, 300);
});
}
// ============================================================
// USER-FACING: FEED, CATEGORIES, CONTENT, QUIZZES
// ============================================================
function loadFeed() {
var feedEl = document.getElementById('lh-feed');
if (!feedEl) return;
feedEl.innerHTML = 'Loading...
';
showFeed();
fetch('/api/learning/feed', { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) { feedEl.innerHTML = 'Failed to load
'; return; }
renderFeed(data.content, feedEl);
})
.catch(function() { feedEl.innerHTML = 'Connection error
'; });
}
function loadCategories() {
fetch('/api/learning/categories', { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) return;
var bar = document.getElementById('lh-categories');
if (!bar) return;
var html = '';
data.categories.forEach(function(c) {
html += '';
});
bar.innerHTML = html;
});
}
function loadCategoryContent(slug) {
var feedEl = document.getElementById('lh-feed');
if (!feedEl) return;
feedEl.innerHTML = 'Loading...
';
showFeed();
fetch('/api/learning/category/' + encodeURIComponent(slug), { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) { feedEl.innerHTML = 'Category not found
'; return; }
renderFeed(data.content, feedEl);
});
}
function searchContent(q) {
var feedEl = document.getElementById('lh-feed');
if (!feedEl) return;
showFeed();
fetch('/api/learning/search?q=' + encodeURIComponent(q), { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) return;
renderFeed(data.content, feedEl);
});
}
function renderFeed(items, feedEl) {
if (!items || items.length === 0) {
feedEl.innerHTML = 'No content yet. Check back soon!
';
return;
}
feedEl.innerHTML = items.map(function(item) {
var typeIcon = item.content_type === 'quiz' ? 'fa-clipboard-question' : item.content_type === 'pearl' ? 'fa-gem' : 'fa-file-alt';
var typeColor = item.content_type === 'quiz' ? 'var(--amber)' : item.content_type === 'pearl' ? 'var(--purple, #8b5cf6)' : 'var(--blue)';
var quizBadge = item.question_count > 0 ? ' ' + item.question_count + ' Q' : '';
var catBadge = item.category_name ? '' + esc(item.category_name) + '' : 'Uncategorized';
var date = item.created_at ? new Date(item.created_at).toLocaleDateString() : '';
return '' +
'' +
'
';
}).join('');
}
function loadContent(slug) {
fetch('/api/learning/content/' + encodeURIComponent(slug), { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) { showToast(data.error || 'Content not found', 'error'); return; }
currentContent = data.content;
showViewer(data.content);
})
.catch(function() { showToast('Failed to load content', 'error'); });
}
function showFeed() {
currentView = 'feed';
var feedEl = document.getElementById('lh-feed');
var viewerEl = document.getElementById('lh-viewer');
var catsEl = document.getElementById('lh-categories');
var searchWrap = document.getElementById('lh-search');
if (feedEl) feedEl.classList.remove('hidden');
if (viewerEl) viewerEl.classList.add('hidden');
if (catsEl) catsEl.classList.remove('hidden');
if (searchWrap) searchWrap.closest('.card').classList.remove('hidden');
}
function showViewer(item) {
currentView = 'viewer';
var feedEl = document.getElementById('lh-feed');
var viewerEl = document.getElementById('lh-viewer');
var catsEl = document.getElementById('lh-categories');
var searchWrap = document.getElementById('lh-search');
if (feedEl) feedEl.classList.add('hidden');
if (viewerEl) viewerEl.classList.remove('hidden');
if (catsEl) catsEl.classList.add('hidden');
if (searchWrap) searchWrap.closest('.card').classList.add('hidden');
var titleEl = document.getElementById('lh-viewer-title');
var metaEl = document.getElementById('lh-viewer-meta');
var bodyEl = document.getElementById('lh-viewer-body');
var quizSection = document.getElementById('lh-quiz-section');
var resultsSection = document.getElementById('lh-quiz-results');
var progressSection = document.getElementById('lh-progress-section');
if (titleEl) titleEl.textContent = item.title;
if (metaEl) {
var parts = [];
if (item.category_name) parts.push(item.category_name);
if (item.subject) parts.push(item.subject);
if (item.author_name) parts.push('by ' + item.author_name);
if (item.created_at) parts.push(new Date(item.created_at).toLocaleDateString());
metaEl.textContent = parts.join(' | ');
}
if (bodyEl) {
// Render body as HTML (admin creates it)
bodyEl.innerHTML = sanitizeHtml(item.body || '');
}
// Quiz
if (quizSection) {
if (item.questions && item.questions.length > 0) {
quizSection.classList.remove('hidden');
renderQuiz(item.questions);
} else {
quizSection.classList.add('hidden');
}
}
if (resultsSection) resultsSection.classList.add('hidden');
// Progress
if (progressSection && item.progress && item.progress.length > 0) {
progressSection.classList.remove('hidden');
var progHtml = item.progress.map(function(p) {
var pct = p.total > 0 ? Math.round((p.score / p.total) * 100) : 0;
var date = new Date(p.completed_at).toLocaleDateString();
return '' +
'' + date + '' +
'' + p.score + '/' + p.total + ' (' + pct + '%)' +
'
';
}).join('');
document.getElementById('lh-progress-list').innerHTML = progHtml;
} else if (progressSection) {
progressSection.classList.add('hidden');
}
}
function renderQuiz(questions) {
var container = document.getElementById('lh-quiz-questions');
var countEl = document.getElementById('lh-quiz-count');
if (!container) return;
if (countEl) countEl.textContent = questions.length + ' question' + (questions.length !== 1 ? 's' : '');
container.innerHTML = questions.map(function(q, idx) {
var typeLabel = q.question_type === 'true_false' ? 'True / False' : 'Multiple Choice';
var optionsHtml = (q.options || []).map(function(opt) {
return '';
}).join('');
return '' +
'' +
'
' + esc(q.question_text) + '
' +
'
' + optionsHtml + '
' +
'
Why incorrect: ' + esc(r.selectedExplanation) + '
';
}
if (!r.isCorrect) {
explHtml += 'Correct answer: ' + esc(r.correctOptionText) + '
';
}
if (r.generalExplanation) {
explHtml += 'Explanation: ' + esc(r.generalExplanation) + '
';
}
return '' +
'' +
explHtml +
'
';
}).join('');
}
// Highlight correct/incorrect in quiz
data.results.forEach(function(r) {
var qDiv = document.querySelector('.lh-quiz-q[data-qid="' + r.questionId + '"]');
if (!qDiv) return;
qDiv.querySelectorAll('.lh-quiz-option').forEach(function(label) {
var input = label.querySelector('input');
if (!input) return;
var optId = parseInt(input.value);
if (optId === r.correctOptionId) label.classList.add('lh-opt-correct');
if (optId === r.selectedOptionId && !r.isCorrect) label.classList.add('lh-opt-wrong');
input.disabled = true;
});
});
// Disable submit button
var submitBtn = document.getElementById('lh-submit-quiz');
if (submitBtn) { submitBtn.disabled = true; submitBtn.innerHTML = ' Submitted'; }
resultsEl.scrollIntoView({ behavior: 'smooth', block: 'start' });
}
function setActiveCatPill(slug) {
document.querySelectorAll('.lh-cat-pill').forEach(function(p) {
p.classList.toggle('active', p.dataset.slug === slug);
});
}
// ============================================================
// ADMIN CMS
// ============================================================
function loadCms() {
loadCmsCategories();
loadCmsContent();
loadCmsStats();
}
function loadCmsStats() {
fetch('/api/admin/learning/stats', { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) return;
var s = data.stats;
var set = function(id, val) { var el = document.getElementById(id); if (el) el.textContent = val; };
set('cms-stat-published', s.publishedContent);
set('cms-stat-drafts', s.totalContent - s.publishedContent);
set('cms-stat-categories', s.totalCategories);
set('cms-stat-quizzes', s.totalQuizzes);
set('cms-stat-attempts', s.totalAttempts);
});
}
function loadCmsCategories() {
fetch('/api/admin/learning/categories', { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) return;
var container = document.getElementById('lh-cms-categories');
if (!container) return;
if (data.categories.length === 0) {
container.innerHTML = 'No categories yet
';
} else {
container.innerHTML = data.categories.map(function(c) {
return '' +
'' + esc(c.name) + '' +
'' + c.content_count + '' +
'' +
'
';
}).join('');
}
// Update category dropdowns (editor + filter)
var sel = document.getElementById('lh-cms-edit-category');
if (sel) {
sel.innerHTML = '';
data.categories.forEach(function(c) {
sel.innerHTML += '';
});
}
var filterSel = document.getElementById('cms-filter-category');
if (filterSel) {
filterSel.innerHTML = '';
data.categories.forEach(function(c) {
filterSel.innerHTML += '';
});
}
});
}
function addCategory() {
var input = document.getElementById('lh-cms-cat-name');
if (!input || !input.value.trim()) { showToast('Enter category name', 'error'); return; }
fetch('/api/admin/learning/categories', {
method: 'POST',
headers: getAuthHeaders(),
body: JSON.stringify({ name: input.value.trim() })
})
.then(function(r) { return r.json(); })
.then(function(data) {
if (data.success) {
input.value = '';
loadCmsCategories();
loadCategories(); // refresh user-facing pills too
showToast('Category created', 'success');
} else showToast(data.error || 'Failed', 'error');
})
.catch(function() { showToast('Request failed', 'error'); });
}
function deleteCategory(id) {
if (!confirm('Delete this category? Content will become uncategorized.')) return;
fetch('/api/admin/learning/categories/' + id, { method: 'DELETE', headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (data.success) { loadCmsCategories(); loadCategories(); showToast('Category deleted', 'info'); }
else showToast(data.error || 'Failed', 'error');
});
}
function loadCmsContent() {
var container = document.getElementById('lh-cms-content-list');
if (!container) return;
container.innerHTML = 'Loading...
';
fetch('/api/admin/learning/content', { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) return;
if (data.content.length === 0) {
container.innerHTML = 'No content yet. Click "New Content" to create.
';
return;
}
window._cmsContentData = data.content;
renderCmsContentList(data.content);
});
}
function renderCmsContentList(items) {
var container = document.getElementById('lh-cms-content-list');
if (!container) return;
if (!items || items.length === 0) {
container.innerHTML = 'No content yet. Click "New Content" to get started.
';
return;
}
container.innerHTML = items.map(function(item) {
var statusBadge = item.published
? 'Published'
: 'Draft';
var typeLabel = item.content_type === 'quiz' ? 'Quiz' : item.content_type === 'pearl' ? 'Pearl' : 'Article';
var qBadge = item.question_count > 0 ? ' ' + item.question_count + 'Q' : '';
var date = item.updated_at ? new Date(item.updated_at).toLocaleDateString() : '';
return '' +
'' + esc(item.title) + qBadge + '
' + esc(item.subject || '') + '' +
'' + esc(item.category_name || 'Uncategorized') + '' +
'' + typeLabel + '' +
'' + statusBadge + '' +
'' + date + '' +
'' +
'
';
}).join('');
}
// CMS search & filter
document.addEventListener('input', function(e) {
if (e.target.id === 'cms-search') filterCmsContent();
});
document.addEventListener('change', function(e) {
if (e.target.id === 'cms-filter-status' || e.target.id === 'cms-filter-category') filterCmsContent();
});
function filterCmsContent() {
var items = window._cmsContentData || [];
var search = (document.getElementById('cms-search') || {}).value || '';
var statusFilter = (document.getElementById('cms-filter-status') || {}).value || 'all';
var catFilter = (document.getElementById('cms-filter-category') || {}).value || 'all';
search = search.toLowerCase().trim();
var filtered = items.filter(function(item) {
if (search && item.title.toLowerCase().indexOf(search) === -1 && (item.subject || '').toLowerCase().indexOf(search) === -1) return false;
if (statusFilter === 'published' && !item.published) return false;
if (statusFilter === 'draft' && item.published) return false;
if (catFilter !== 'all' && String(item.category_id) !== catFilter) return false;
return true;
});
renderCmsContentList(filtered);
}
// Editor toolbar — insert HTML tags at cursor in textarea
function insertTag(tag) {
var ta = document.getElementById('lh-cms-edit-body');
if (!ta) return;
var start = ta.selectionStart, end = ta.selectionEnd;
var sel = ta.value.substring(start, end);
var insert = '';
switch(tag) {
case 'b': case 'i': case 'u': case 'code': case 'h2': case 'h3':
insert = '<' + tag + '>' + (sel || 'text') + ''; break;
case 'a':
var url = prompt('Enter URL:');
if (!url) return;
insert = '' + (sel || 'link text') + ''; break;
case 'ul': insert = '\n - ' + (sel || 'item') + '
\n \n
'; break;
case 'ol': insert = '\n - ' + (sel || 'item') + '
\n \n
'; break;
case 'blockquote': insert = '' + (sel || 'quote') + '
'; break;
case 'table': insert = '\n| Header 1 | Header 2 |
|---|
\n| ' + (sel || 'data') + ' | |
\n
'; break;
case 'hr': insert = '
'; break;
default: return;
}
ta.value = ta.value.substring(0, start) + insert + ta.value.substring(end);
ta.focus();
ta.selectionStart = ta.selectionEnd = start + insert.length;
}
function openEditor(contentId, contentType) {
var editor = document.getElementById('lh-cms-editor');
var listView = document.getElementById('cms-list-view');
if (!editor) return;
editor.classList.remove('hidden');
if (listView) listView.classList.add('hidden');
// Reset
document.getElementById('lh-cms-edit-id').value = '';
document.getElementById('lh-cms-edit-title').value = '';
document.getElementById('lh-cms-edit-subject').value = '';
document.getElementById('lh-cms-edit-body').value = '';
document.getElementById('lh-cms-edit-category').value = '';
document.getElementById('lh-cms-edit-type').value = contentType || 'article';
document.getElementById('lh-cms-edit-published').value = 'false';
document.getElementById('lh-cms-questions').innerHTML = '';
document.getElementById('btn-lh-delete-content').classList.add('hidden');
// For quiz type, add a starter question
if (contentType === 'quiz' && !contentId) {
addQuestionBlock();
}
if (!contentId) return;
// Load existing content
fetch('/api/admin/learning/content/' + contentId, { headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) { showToast('Failed to load', 'error'); return; }
var c = data.content;
document.getElementById('lh-cms-edit-id').value = c.id;
document.getElementById('lh-cms-edit-title').value = c.title;
document.getElementById('lh-cms-edit-subject').value = c.subject || '';
document.getElementById('lh-cms-edit-body').value = c.body || '';
document.getElementById('lh-cms-edit-category').value = c.category_id || '';
document.getElementById('lh-cms-edit-type').value = c.content_type || 'article';
document.getElementById('lh-cms-edit-published').value = c.published ? 'true' : 'false';
document.getElementById('btn-lh-delete-content').classList.remove('hidden');
// Load questions
var qContainer = document.getElementById('lh-cms-questions');
qContainer.innerHTML = '';
if (c.questions && c.questions.length > 0) {
c.questions.forEach(function(q) { addQuestionBlock(q); });
}
editor.scrollIntoView({ behavior: 'smooth' });
});
}
function closeEditor() {
var editor = document.getElementById('lh-cms-editor');
var listView = document.getElementById('cms-list-view');
if (editor) editor.classList.add('hidden');
if (listView) listView.classList.remove('hidden');
}
function saveContent() {
var id = document.getElementById('lh-cms-edit-id').value;
var title = document.getElementById('lh-cms-edit-title').value.trim();
var subject = document.getElementById('lh-cms-edit-subject').value.trim();
var body = document.getElementById('lh-cms-edit-body').value;
var category_id = document.getElementById('lh-cms-edit-category').value || null;
var content_type = document.getElementById('lh-cms-edit-type').value;
var published = document.getElementById('lh-cms-edit-published').value === 'true';
if (!title) { showToast('Title required', 'error'); return; }
// Gather questions with validation
var questions = [];
var validationError = false;
var qBlocks = document.querySelectorAll('#lh-cms-questions .lh-question-block');
for (var qi = 0; qi < qBlocks.length; qi++) {
var qBlock = qBlocks[qi];
var qText = qBlock.querySelector('.lh-q-text').value.trim();
if (!qText) continue;
var qType = qBlock.querySelector('.lh-q-type').value;
var qExpl = qBlock.querySelector('.lh-q-explanation').value.trim();
var qId = qBlock.dataset.questionId || null;
var options = [];
qBlock.querySelectorAll('.lh-option-row').forEach(function(row) {
var optText = row.querySelector('.lh-opt-text').value.trim();
if (!optText) return;
options.push({
option_text: optText,
is_correct: row.querySelector('.lh-opt-correct').checked,
explanation: row.querySelector('.lh-opt-expl').value.trim()
});
});
// Validate: must have a correct answer marked
var hasCorrect = options.some(function(o) { return o.is_correct; });
if (options.length > 0 && !hasCorrect) {
showToast('Question "' + qText.substring(0, 50) + '..." needs a correct answer marked', 'error');
qBlock.style.outline = '2px solid var(--red)';
qBlock.scrollIntoView({ behavior: 'smooth', block: 'center' });
validationError = true;
break;
}
qBlock.style.outline = '';
questions.push({
id: qId,
question_text: qText,
question_type: qType,
explanation: qExpl,
options: options
});
}
if (validationError) return;
var payload = { title: title, body: body, category_id: category_id, subject: subject, content_type: content_type, published: published };
var method = id ? 'PUT' : 'POST';
var url = id ? '/api/admin/learning/content/' + id : '/api/admin/learning/content';
showLoading('Saving...');
fetch(url, { method: method, headers: getAuthHeaders(), body: JSON.stringify(payload) })
.then(function(r) { return r.json(); })
.then(function(data) {
if (!data.success) { hideLoading(); showToast(data.error || 'Save failed', 'error'); return; }
var contentId = id || data.id;
// Save questions sequentially
saveQuestions(contentId, questions, 0, function() {
hideLoading();
showToast('Content saved', 'success');
closeEditor();
loadCmsContent();
loadCmsStats();
loaded = false; // force refresh user feed
});
})
.catch(function() { hideLoading(); showToast('Save failed', 'error'); });
}
function saveQuestions(contentId, questions, index, callback) {
if (index >= questions.length) { callback(); return; }
var q = questions[index];
var qId = q.id;
var method, url;
if (qId) {
method = 'PUT';
url = '/api/admin/learning/questions/' + qId;
} else {
method = 'POST';
url = '/api/admin/learning/content/' + contentId + '/questions';
}
fetch(url, {
method: method,
headers: getAuthHeaders(),
body: JSON.stringify({
question_text: q.question_text,
question_type: q.question_type,
explanation: q.explanation,
options: q.options
})
})
.then(function(r) { return r.json(); })
.then(function() {
saveQuestions(contentId, questions, index + 1, callback);
})
.catch(function() {
saveQuestions(contentId, questions, index + 1, callback);
});
}
function deleteContent() {
var id = document.getElementById('lh-cms-edit-id').value;
if (!id) return;
if (!confirm('Delete this content and all its questions? This cannot be undone.')) return;
fetch('/api/admin/learning/content/' + id, { method: 'DELETE', headers: getAuthHeaders() })
.then(function(r) { return r.json(); })
.then(function(data) {
if (data.success) {
showToast('Content deleted', 'info');
closeEditor();
loadCmsContent();
loadCmsStats();
loaded = false;
} else showToast(data.error || 'Failed', 'error');
});
}
function addQuestionBlock(existingQ) {
var container = document.getElementById('lh-cms-questions');
if (!container) return;
var block = document.createElement('div');
block.className = 'lh-question-block';
if (existingQ && existingQ.id) block.dataset.questionId = existingQ.id;
var qNum = container.querySelectorAll('.lh-question-block').length + 1;
block.innerHTML =
'' +
'
' +
'Q' + qNum + '' +
'' +
'
' +
'
' +
'
' +
'' +
'
' +
'' +
'' +
'' +
'' +
'' +
'
';
container.appendChild(block);
var optList = block.querySelector('.lh-options-list');
if (existingQ && existingQ.options && existingQ.options.length > 0) {
existingQ.options.forEach(function(opt) { addOptionRow(optList, opt); });
} else if (existingQ && existingQ.question_type === 'true_false') {
addOptionRow(optList, { option_text: 'True', is_correct: false, explanation: '' });
addOptionRow(optList, { option_text: 'False', is_correct: false, explanation: '' });
} else {
// Add 4 blank MCQ options
for (var i = 0; i < 4; i++) addOptionRow(optList, null);
}
}
function addOptionRow(container, opt) {
if (!container) return;
var row = document.createElement('div');
row.className = 'lh-option-row';
row.innerHTML =
'' +
'' +
'' +
'';
container.appendChild(row);
}
// ── Helpers ──────────────────────────────────────────────────
function esc(str) {
if (!str) return '';
return String(str).replace(/&/g, '&').replace(//g, '>').replace(/"/g, '"');
}
function sanitizeHtml(html) {
// Allowlist-based sanitizer: only safe tags and no event handlers
var ALLOWED_TAGS = ['p','br','b','strong','i','em','u','s','h1','h2','h3','h4','h5','h6',
'ul','ol','li','a','blockquote','code','pre','table','thead','tbody','tr','th','td',
'hr','div','span','sub','sup','dl','dt','dd'];
var ALLOWED_ATTRS = { 'a': ['href'], 'td': ['colspan','rowspan'], 'th': ['colspan','rowspan'] };
var div = document.createElement('div');
div.innerHTML = html;
function clean(node) {
var children = Array.prototype.slice.call(node.childNodes);
for (var i = 0; i < children.length; i++) {
var child = children[i];
if (child.nodeType === 3) continue; // text nodes OK
if (child.nodeType !== 1) { child.remove(); continue; } // remove comments etc
var tag = child.tagName.toLowerCase();
if (ALLOWED_TAGS.indexOf(tag) === -1) {
// Replace with text content
var text = document.createTextNode(child.textContent);
node.replaceChild(text, child);
continue;
}
// Remove all attributes except explicitly allowed ones
var allowed = ALLOWED_ATTRS[tag] || [];
var attrs = Array.prototype.slice.call(child.attributes);
for (var j = 0; j < attrs.length; j++) {
if (allowed.indexOf(attrs[j].name) === -1) {
child.removeAttribute(attrs[j].name);
}
}
// For tags, validate href is not javascript:
if (tag === 'a') {
var href = (child.getAttribute('href') || '').trim().toLowerCase();
if (href.indexOf('javascript:') === 0 || href.indexOf('data:') === 0 || href.indexOf('vbscript:') === 0) {
child.setAttribute('href', '#');
}
child.setAttribute('rel', 'noopener noreferrer');
child.setAttribute('target', '_blank');
}
clean(child);
}
}
clean(div);
return div.innerHTML;
}
})();