检查jinja2模板内EmailField的ListField中是否有电子邮件

Question

背景：

我的课程如下：

class DisplayArtwork(Document):
    name = StringField(required=True)
    email = EmailField(required=True)
    country = StringField(required=True)
    phone = StringField()
    artname = StringField(required=True)
    medium = StringField(required=True)
    caption = StringField(required=True)
    filename = StringField(required=True)
    votes = ListField(EmailField())
    published = DateTimeField(required=True)

然后我将

DisplayArtwork.objects

发送到 Flask/jinja2 模板中，如下所示：

@app.route("/gallery")
def gallery():
    return render_template("gallery.html", artworks=DisplayArtwork.objects)

模板内部是一个 for 循环，它迭代所有

DisplayArtwork

：

{% for artwork in artworks %}

我的问题是：我可以检查当前用户的电子邮件（

current_user.get_id()

）是否在

ListField(EmailField())

内吗？

我尝试过的：

首先，我检查当前用户是否已通过身份验证，然后检查

artwork['votes'][current_user.get_id()]

是否已定义。

{% if current_user.is_authenticated %}
    {% if artwork['votes'][current_user.get_id()] is defined%}
         <button id="{{ artwork['filename']}}" type="button" class="btn btn-success" onclick='upvote(`{{artwork["filename"]}}`)'>Upvotes: {{artwork['votes']|length}}</button>
    {% else %}
         <button id="{{ artwork['filename']}}" type="button" class="btn btn-outline-success" onclick='upvote(`{{artwork["filename"]}}`)'>Upvotes: {{artwork['votes']|length}}</button>
    {% endif %}
{% else %}
    <a href="/login" class="btn btn-success">Login to Upvote</a>
{% endif %}

upvote()

函数的工作原理如下：

function upvote(filename) {
    const formData = new FormData();
    formData.append('filename', filename);
    fetch('/upvote', {
        method: 'post',
        body: formData
    });
    upvotebutton = document.getElementById(filename);
    if (!upvotebutton) {alert('Error: ${filename} button not found');}
    if (upvotebutton.classList.contains('btn-outline-success')) {
        upvotebutton.classList.remove('btn-outline-success');
        upvotebutton.classList.add('btn-success');
        upvotebutton.innerHTML = 'Upvotes: ' + (parseInt(upvotebutton.innerHTML.split(' ')[1]) + 1);
    }
    else if (upvotebutton.classList.contains('btn-success')) {
        upvotebutton.classList.remove('btn-success');
        upvotebutton.classList.add('btn-outline-success');
        upvotebutton.innerHTML = 'Upvotes: ' + (parseInt(upvotebutton.innerHTML.split(' ')[1]) - 1);
    }

}

然后由后端的此函数处理：

@app.route("/upvote", methods=["POST"])
def upvote():
    if current_user.is_authenticated:
        artwork = DisplayArtwork.objects(filename=request.form["filename"])
        if artwork:
            response = None
            try:
                artwork.update(pull__votes=current_user.get_id())
                response = "downvoted"
            except KeyError:
                artwork.update(add_to_set__votes=[current_user.get_id()])
                response = "upvoted"
            return response, 200
        return "Failed to upvote", 500
    return "Login to upvote", 401

不幸的是，这总是显示用户没有投票。

如何使投票功能发挥作用？

Answer 1

我明白了！

这是我改变的。

首先，在jinja2模板中，我像这样检查了电子邮件：

{% if current_user.get_id() in artwork.votes %}

而不是

{% if artwork['votes'][current_user.get_id()] is defined%}

。

接下来，我将点赞功能更改为这样：

@app.route("/upvote", methods=["POST"])
def upvote():
    if current_user.is_authenticated:
        artwork = DisplayArtwork.objects(filename=request.form["filename"]).first()
        if artwork:
            user_email = current_user.get_id()
            if user_email in artwork.votes:
                artwork.update(pull__votes=user_email)
                return "downvoted", 200
            else:
                artwork.update(add_to_set__votes=user_email)
                return "upvoted", 200
        return "Failed to upvote", 500
    return "Login to upvote", 401

artwork.update(pull__votes=user_email)

不会抛出KeyError，所以我将其更改为手动检查电子邮件是否在列表中，然后决定要做什么。

我还忘记添加

.first()

来获取一件艺术品而不是列表。