Flask / WTForms中的动态表单（Formsets）？ [英] Dynamic Forms (Formsets) in Flask / WTForms?

问题描述

在Django中，您有一个称为Formsets的多表单功能，您可以使用这个功能将多个表单创建为同一个模板。我试图在Flask / WTforms中实现类似的功能。

 < form action ={{url_for（'request-accept '）}}method ='post'> 
< table> 
< tbody> 
 {％请求中的请求％} 
< tr> 
< td> 
< div class =person-header> 
< img src ={{request.profile_pic_url}}class =img-circle profile-image/> 
< p class =person-header-text> {{request.fullname（）}}< / p> 
< / div> 
< / td> 
< td> 
< input type =checkboxid ={{request.key.urlsafe（）}}name =checkbox {{loop.index}}> 
< / td> 
< / tr> 
 {％endfor％} 
< / tbody> 
< / table> 
 
< input class ='submit btn btn-primary'type = submit value =Connect> 
< / form> 
  

这个想法是用一种形式来包装所有的复选框，用户喜欢打勾成为朋友用。就目前而言，我并不是真的在Flask中生成任何表单类，因为我不知道如何创建一个动态FormSet，因此我在html中动态地创建了表单。

不过，我不知道如何通过复选框来检索选定的用户标识。 （我已经将它存储在 id中，因为我不知道更好）



但是我无法访问 request.values ['checkbox1'] 中的id。我只能看到它的在或 off 。

有什么建议如何解决这个请吗？

解决方案

问题

c> id 不会被发送回服务器 - 只有 value 是...因为你的复选框没有 em> a value 属性使用默认值，这恰好是在上。

由于您使用 wtforms ，我会给你一个你如何做这个的例子。

不要再有这个问题了

WTForms的文档有一个示例这个类会为你创建一个复选框列表：
$ b $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $>类MultiCheckboxField（SelectMultipleField）

多选，除了显示复选框列表

迭代该字段将产生子字段，允许自定义渲染
封闭的复选框字段。

widget = widgets.ListWidget（prefix_label = False）
option_widget = widgets.CheckboxInput（）

您可以在您的自定义表单中以这种方式使用此字段：

  class FriendsForm （Form）：
 potential_friends = MultiCheckboxField（Friends，coerce = int）
 
＃... later ... 
 
 @ app.route（ / add-friends，methods = [GET，POST]）
 def add_friends（）：
 form = FriendsForm（request.form）
＃将使用一个静态列表
 form.potential_friends.choices = [（1，Sam），（2，Joe）] 
 
＃我们还需要ID到Person实例
＃（用这个例子 - 用你自己的;-)）
 mapping = {
 1：Person（Sam，profile_pic =sam.jpg） ，
 2：Person（Joe，profile_pic =joe.png）
} 
 
如果request.method ==POST：
＃标记新朋友
 
返回render_templ ate（friends.html，form = form，persons = mapping）
  

然后在 friends.html 你可以迭代 form.potential_friends 字段：

  {for person in form.potential_friends％} 
 persons [person.data] .profile_pic :: {{person.label}} :: {{person}}<峰; br> 
 {％endfor％} 
  

您可以在 for 循环。我的特殊例子应该呈现（具有更多的属性，比如和名称） ：

  sam.jpg ::< label> Sam< / label> ::< input type =checkboxvalue =1> 
 joe.png ::< label> Joe< / label> ::< input type =checkboxvalue =2> 
  

In Django you have a multiple form feature called Formsets, which you can use to create multiple forms into the same template. I am trying to achieve something similar in Flask / WTforms.

<form action="{{ url_for('request-accept') }}" method='post'>           
   <table>
        <tbody>
            {% for request in requests %}
                    <tr>                    
                        <td>                        
                           <div class="person-header">
                              <img src="{{request.profile_pic_url}}" class="img-circle profile-image"/>
                              <p class="person-header-text">{{request.fullname()}}</p>    
                           </div>
                       </td>                
                       <td>
                           <input type="checkbox" id="{{request.key.urlsafe()}}" name="checkbox{{loop.index}}">
                       </td>                    
                   </tr>
           {% endfor %}
    </tbody>            
  </table>

  <input class='submit btn btn-primary' type=submit value="Connect">            
</form>

The idea is having one form that wrapps all the checkboxes, which the user like to tick to become friends with. As it currently stands I am not really generating any form class in Flask, since I don't know how to make a dynamic FormSet, hence I create the form dynamically inside the html.

The caveat is though, I don't know how to retrieve the selected user id via the checkbox. (I have stored it in the id because I didn't know better)

But I can't access the id in request.values['checkbox1']. I can only see if its on or off.

Any suggestions how to solve this please?

解决方案

The problem

Your problem is that id is not sent back to the server - only value is ... and since your checkboxes don't have a value attribute the default value is used, which happens to be on.

Since you tagged this with wtforms, I'll give you an example of how you could be doing this.

Never have this issue again

The WTForms' documentation has an example class that will create a list of checkboxes for you:

class MultiCheckboxField(SelectMultipleField):
    """
    A multiple-select, except displays a list of checkboxes.

    Iterating the field will produce subfields, allowing custom rendering of
    the enclosed checkbox fields.
    """
    widget = widgets.ListWidget(prefix_label=False)
    option_widget = widgets.CheckboxInput()

You would use this field in your custom form in this manner:

class FriendsForm(Form):
    potential_friends = MultiCheckboxField("Friends", coerce=int)

# ... later ...

@app.route("/add-friends", methods=["GET", "POST"])
def add_friends():
    form = FriendsForm(request.form)
    # lookup friends, for now we'll use a static list
    form.potential_friends.choices = [(1, "Sam"), (2, "Joe")]

    # We'll also need a mapping of IDs to Person instances
    # (Made up for this example - use your own ;-) )
    mapping = {
        1: Person("Sam", profile_pic="sam.jpg"),
        2: Person("Joe", profile_pic="joe.png")
    }

    if request.method == "POST":
        # Mark new friends

    return render_template("friends.html", form=form, persons=mapping)

Then, in friends.html you can iterate over the form.potential_friends field:

{% for person in form.potential_friends %}
    persons[person.data].profile_pic :: {{person.label}} :: {{person}}<br>
{% endfor %}

You can customize your HTML inside the for loop. My particular example should render (with a few more attributes, like for and name):

sam.jpg :: <label>Sam</label> :: <input type="checkbox" value="1">
joe.png :: <label>Joe</label> :: <input type="checkbox" value="2">

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