@blog_bp.route('/')
def index():

@blog_bp.route('/')
def index():
    page = request.args.get('page', 1, type=int) # 從查詢字符串獲取當前頁數
    per_page = current_app.config['BLUELOG_POST_PER_PAGE'] # 每頁數量
    pagination = Post.query.order_by(Post.timestamp.desc()).paginate(page, per_page=per_page) # 分頁對象
    posts = pagination.items # 當前頁數的記錄列表
    return render_template('blog/index.html', pagination=pagination, posts=posts)

{% from 'bootstrap/pagination.html' import render_pager %}
...
{{ render_pager(pagination) }}

@blog_bp.route('/post/<int:post_id>')
def show_post(post_id):
	post = Post.query.get_or_404(post_id)
	return render_template('blog/post.html', post=post)

@blog_bp.route('/category/<int:category_id>')
def show_category(category_id):
    category = Category.query.get_or_404(category_id)
    page = request.args.get('page', 1, type=int)
    per_page = current_app.config['BLUELOG_POST_PER_PAGE']
    pagination = Post.query.with_parent(category).order_by(Post.timestamp.desc()).paginate(page, per_page)
    posts = pagination.items
    return render_template('blog/category.html', category=category, pagination=pagination, posts=posts)

@blog_bp.route('/post/<int:post_id>', methods=['GET', 'POST'])
def show_post(post_id):
    post = Post.query.get_or_404(post_id)
    page = request.args.get('page', 1, type=int)
    per_page = current_app.config['BLUELOG_COMMENT_PER_PAGE']
    pagination = Comment.query.with_parent(post).filter_by(reviewed=True).order_by(Comment.timestamp.asc()).paginate(page, per_page)
    comments = pagination.items
    return render_template('blog/post.html', post=post, pagination=pagination, form=form, comments=comments)

from bluelog.models import Comment
from bluelog.forms import AdminCommentForm, CommentForm
from bluelog.emails import send_new_comment_email
@blog_bp.route('/post/<int:post_id>', methods=['GET', 'POST'])
def show_post(post_id):
    post = Post.query.get_or_404(post_id)
    page = request.args.get('page', 1, type=int)
    per_page = current_app.config['BLUELOG_COMMENT_PER_PAGE']
    pagination = Comment.query.with_parent(post).filter_by(reviewed=True).order_by(Comment.timestamp.asc()).paginate(page, per_page)
    comments = pagination.items
    if current_user.is_authenticated: # 如果當前用戶已登錄，使用管理員表單
        form = AdminCommentForm()
        form.author.data = current_user.name
        form.email.data = current_app.config['BLUELOG_EMAIL']
        form.site.data = url_for('.index')
        from_admin = True
        reviewed = True
    else:   # 未登錄則使用普通表單                         
        form = CommentForm()
        from_admin = False
        reviewed = False
    if form.validate_on_submit():
        author = form.author.data
        email = form.email.data
        site = form.site.data
        body = form.body.data
        comment = Comment(
            author=author, email=email, site=site, body=body,
            from_admin=from_admin, post=post, reviewed=reviewed)
        db.session.add(comment)
        db.session.commit()
        if current_user.is_authenticated:  # 根據登錄狀態不同顯示不同的提示信息
            flash('Comment published.', 'success')
        else:
            flash('Thanks, your comment will be published after reviewed.', 'info')
            send_new_comment_email(post)  # 發送郵件給管理員
        return redirect(url_for('.show_post', post_id=post_id))
    return render_template('blog/post.html', post=post, pagination=pagination, form=form, comments=comments)

<a class="btn btn-primary btn-sm" href="{{ url_for('.reply_comment',comment_id=comment.id) }}"  ></a>

@blog_bp.route('/reply/comment/<int:comment_id>')
def reply_comment(comment_id):
    comment = Comment.query.get_or_404(comment_id)
    if not comment.post.can_comment:
        flash('Comment is disabled.', 'warning')
        return redirect(url_for('.show_post', post_id=comment.post.id))
    return redirect(
        url_for('.show_post', post_id=comment.post_id, reply=comment_id, author=comment.author) + '#comment-form')

{% if request.args.get('reply') %}
	<div class="alert alert-dark">
		Reply to <strong>{{ request.args.get('author') }}</strong>:
		<a class="float-right" href="{{ url_for('.show_post',post_id=post.id) }}"  >Cancel</a>
	</div>
{% endif %}

from bluelog.emails import send_new_reply_email
@blog_bp.route('/post/<int:post_id>', methods=['GET', 'POST'])
def show_post(post_id):
	...
	if form.validate_on_submit():
		...
		replied_id = request.args.get('reply')
		if replied_id: # 如果 URL 中 reply 查詢參數存在，那么說明是回復
			replied_comment= Comment.query.get_or_404(replied_id)
			comment.replied = replied_comment
			send_new_reply_email(replied_comment) # 發送郵件給被回復用戶
		...

# ('theme name', 'display name')
BLUELOG_THEMES = {'perfect_blue': 'Perfect Blue', 'black_swan': 'Black Swan'}

@blog_bp.route('/change-theme/<theme_name>')
def change_theme(theme_name):
    if theme_name not in current_app.config['BLUELOG_THEMES'].keys():
        abort(404)
    response = make_response(redirect_back())
    response.set_cookie('theme', theme_name, max_age=30 * 24 * 60 * 60)
    return response

<link 
      href="{{ url_for('static', filename='css/%s.min.css' % request.cookies.get('theme', 'perfect_blue')) }}"  
      type="text/css">

<div class="dropdown">
    <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenuButton"
            data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        Change Theme
    </button>
    <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
        {% for theme_name, display_name in config.BLUELOG_THEMES.items() %}
            <a class="dropdown-item"
               href="{{ url_for('blog.change_theme', theme_name=theme_name, next=request.full_path) }}"  >
                {{ display_name }}</a>
        {% endfor %}
    </div>
</div>