Flask 学习 十二 用户评论

评论在数据库中的表示

由于评论和2个模型有关系,分别是谁发了评论,以及评论了哪个文章,所以这次要更新数据库模型

models.py 创建用户评论数据库模型

class Comment(db.Model):
    __tablename__ = 'comments'
    id = db.Column(db.Integer, primary_key=True)
    body = db.Column(db.Text)
    timestamp = db.Column(db.DateTime,index=True,default=datetime.utcnow)
    body_html = db.Column(db.Text)
    disabled = db.Column(db.Boolean) # 管理员用来查禁不当评论
    author_id = db.Column(db.Integer, db.ForeignKey('users.id'))
    post_id = db.Column(db.Integer,db.ForeignKey('posts.id'))

    @staticmethod
    def on_changed_body(target,value,oldvalue,initiator):
        allowed_tags=['a','abbr','acronym','b','code','em','i','strong']
        target.body_html=bleach.linkify(bleach.clean(markdown(value,output_format='html'),tags=allowed_tags,strip=True))
db.event.listen(Comment.body,'set',Comment.on_changed_body)

User和Post里面也要和Comment设置相应的关系

class User(db.Model):  
# ...  
comments = db.relationship('Comment', backref='author', lazy='dynamic')  
class Post(db.Model):  
# ...  
comments = db.relationship('Comment', backref='post', lazy='dynamic')  

提交和显示评论

main/forms.py 创建评论输入表单

class CommentForm(FlaskForm):
    body = StringField('输入你的评论',validators=[DataRequired()])
    submit = SubmitField('提交')

为支持评论更新路由post

main/views.py 支持博客文章评论

# 文章固定链接
@main.route('/post/<int:id>', methods=['GET', 'POST'])
def post(id):
    post = Post.query.get_or_404(id)
    form = CommentForm()
    if form.validate_on_submit():
        # current_user(上下文代理对象)._get_current_object() 真正的User对象
        comment = Comment(body=form.body.data,
                          post=post,
                          author=current_user._get_current_object())
        db.session.add(comment)
        flash('你已经发布了新评论.')
        # page设为-1,用来请求评论的最后一页,刚提交的评论才会出现在页面中
        return redirect(url_for('.post', id=post.id, page=-1))
    page = request.args.get('page', 1, type=int)
    # 程序获取页数,发现时-1时,会计算总量和总页数得出真正显示的页数
    if page == -1:
        page = (post.comments.count() - 1) // 
            current_app.config['FLASKY_COMMENTS_PER_PAGE'] + 1
    pagination = post.comments.order_by(Comment.timestamp.asc()).paginate(
        page, per_page=current_app.config['FLASKY_COMMENTS_PER_PAGE'],
        error_out=False)
    comments = pagination.items
    return render_template('post.html', posts=[post], form=form,
                           comments=comments, pagination=pagination)

评论模板 _comment.html

<ul class="comments">
    {% for comment in comments %}
    <li class="comment">
        <div class="comment-thumbnail">
            <a href="{{ url_for('.user', username=comment.author.username) }}">
                <img class="img-rounded profile-thumbnail" src="{{ comment.author.gravatar(size=40) }}">
            </a>
        </div>
        <div class="comment-content">
            <div class="comment-date">{{ moment(comment.timestamp).fromNow() }}</div>
            <div class="comment-author"><a href="{{ url_for('.user', username=comment.author.username) }}">{{ comment.author.username }}</a></div>
            <div class="comment-body">
                {% if comment.body_html %}
                    {{ comment.body_html | safe }}
                {% else %}
                    {{ comment.body }}
                {% endif %}
            </div>
        </div>
    </li>
    {% endfor %}
</ul>

评论引入post.html

{% extends "base.html" %}
{% import "bootstrap/wtf.html" as wtf %}
{% import '_macros.html' as macros %}
{% block title %}Flasky - 文章{% endblock %}

{% block page_content %}
{% include '_posts.html' %}

<h4 id="comments">评论</h4>
{% if current_user.can(Permission.COMMENT) %}
    <div class="comment-form">
        {{ wtf.quick_form(form) }}
    </div>
{% endif %}
{% include '_comments.html' %}
{% if pagination %}
    <div class="pagination">
        {{ macros.pagination_widget(pagination, '.post', fragment='#comments', id=posts[0].id) }}
    </div>
{% endif %}
{% endblock %}

上面加在 _posts.html里面的这段话,在url地址后面,加了一个 #comments

这个叫做URL片段

可以理解为:#这个符号,在URL地址里面相当于分隔符

#左边的,代表真实URL,对外的,就是普通用户可以看到的URL

#右边的,代表对网页内部的代码,在浏览器的地址栏是看不到的,他针对的是,当前页面HTML文件内,id=comments的内容

具体作用是:当加载这个页面时,直接会将这个id处于的位置,滚到页面顶端

类似于平时的用户体验是:当评论完以后,页面重新加载,评论区域会自动翻滚到页面最上端,体验很好。

按了comments按钮以后,可以直接跳转到post页面的评论区域,等于是个页中页功能。

链接到博客的评论_post.html

<a href="{{ url_for('.post', id=post.id) }}#comments">
   <span class="label label-primary">{{ post.comments.count() }} 评论</span>
</a>

user.html 增加评论数

<p><b> 评论数量:</b>{{ user.comments.count() }}.</p>

_macro.html 宏需要加入片断参数

{% macro pagination_widget(pagination,endpoint,fragment='') %}
<ul class="pagination">
    <li {% if not pagination.has_prev %}class="disabled" {% endif %}>
        <a href="{% if pagination.has_prev %}{{ url_for(endpoint,page = pagination.prev_num,**kwargs) }}{{ fragment }}{% else %}#{% endif %}">
        &laquo;
        </a>
    </li>
    {% for p in pagination.iter_pages() %}
        {% if p %}
            {% if p ==pagination.page %}
            <li class="active">
                <a href="{{ url_for(endpoint,page=p,**kwargs) }}{{ fragment }}">{{ p }}</a>
            </li>
            {% else %}
            <li>
                <a href="{{ url_for(endpoint,page=p,**kwargs) }}{{ fragment }}">{{ p }}</a>
            </li>
            {% endif %}
        {% else %}
            <li class="disabled"><a href="#">&hellip;</a></li>
        {% endif %}
    {% endfor %}
    <li {% if not pagination.has_next %}class="disabled" {% endif %}>
        <a href="{% if pagination.has_next %}{{ url_for(endpoint,page = pagination.next_num,**kwargs) }}{{ fragment }}{% else %}#{% endif %}">
        &raquo;
        </a>
    </li>
</ul>
{% endmacro %}

 管理评论

base.html加入评论管理导航条

{% if current_user.can(Permission.MODERATE_COMMENTS) %}
<li>
    <a href="{{ url_for('main.moderate') }}">评论管理</a>
</li>
{% endif %}

main/views.py 管理评论路由

@main.route('/moderate')
@login_required
@permission_required(Permission.MODERATE_COMMENTS)
def moderate():
    page = request.args.get('page', 1, type=int)
    pagination = Comment.query.order_by(Comment.timestamp.desc()).paginate(
        page, per_page=current_app.config['FLASKY_COMMENTS_PER_PAGE'],
        error_out=False)
    comments = pagination.items
    return render_template('moderate.html',comments=comments,pagination=pagination,page=page)

moderate.html 评论管理页面模板

{% extends "base.html" %}
{% import '_macros.html' as macros %}
{% block title %}Flasky - 评论管理{% endblock %}

{% block page_content %}
    <div class="page-header">
        <h1>评论管理</h1>
    </div>
    {% set moderate = True %} # 决定是否渲染评论管理功能
    {% include '_comments.html' %}
    {% if pagination %}
    <div class="pagination">
        {% if pagination %}
    <div class="pagination">
        {{ macros.pagination_widget(pagination, '.moderate') }}
    </div>
{% endif %}
    </div>
{% endif %}
{% endblock %}

_comments.html 评论正文

 <div class="comment-body">
                {% if comment.disabled %}
                    <p><i>此评论已被管理员禁用</i></p>
                {% endif %}
                {% if moderate or not comment.disabled %}
                    {% if comment.body_html %}
                        {{ comment.body_html | safe }}
                    {% else %}
                        {{ comment.body }}
                    {% endif %}
                {% endif %}
            </div>
            {% if moderate %}
         <br> {% if comment.disabled %}
<a class="btn btn-default btn-xs" href="{{ url_for('.moderate_enable',id=comment.id,page=page) }}">恢复</a> {% else %} <a class="btn btn-default btn-xs" href="{{ url_for('.moderate_disable',id=comment.id,page=page) }}">禁用</a> {% endif %} {% endif %}
</div>

main.views.py 评论管理路由

@main.route('/moderate/enable/<int:id>')
@login_required
@permission_required(Permission.MODERATE_COMMENTS)
def moderate_enable(id):
    comment = Comment.query.get_or_404(id)
    comment.disabled = False
    db.session.add(comment)
    return redirect(url_for('.moderate',page=request.args.get('page',1,type=int)))

@main.route('/moderate/disable/<int:id>')
@login_required
@permission_required(Permission.MODERATE_COMMENTS)
def moderate_disable(id):
    comment = Comment.query.get_or_404(id)
    comment.disabled = True
    db.session.add(comment)
    return redirect(url_for('.moderate',page=request.args.get('page',1,type=int)))
原文地址:https://www.cnblogs.com/Erick-L/p/6938009.html