使用flask-wtf和sqlalchemy生成动态表单

Question

我有一个webapp,允许用户创建自己的字段,以便稍后在表单中呈现.

我有一个模型Formfield如下:

class Formfield(db.Model):
    id = db.Column(db.Integer, primary_key = True)
    form_id = db.Column(db.Integer, db.ForeignKey('formbooking.id'))
    label = db.Column(db.String(80))
    placeholder_text = db.Column(db.String(80))
    help_text = db.Column(db.String(500))
    box_checked = db.Column(db.Boolean, nullable = True, default = False)
    options = db.Column(db.String) # JSON goes here?
    answer = db.Column(db.String)
    required = db.Column(db.Boolean, nullable = False, default = False)
    order = db.Column(db.Integer)
    fieldtype = db.Column(db.Integer) 

我用来表示一个字段,无论种类如何(复选框,输入,以后更多).

如您所见,每个字段都有一个Form_id的FK.

我正在尝试为给定的form_id生成动态表单.问题是我需要确定要为每个Formfield呈现的字段类型.所以我还需要在某个时候处理字段类型.

我想解决方案是以某种方式将form_id传递给我的Form类中的函数.

我不知道如何做到这一点或在哪里寻找解决方案.

任何帮助将非常感谢!

Answer 1

我想我设法用这里的想法创建动态表单https://groups.google.com/forum/#!topic/wtforms/cJl3aqzZieA

您必须在视图函数中创建动态表单,获取要获取的表单域,并迭代每个字段以构造此表单对象.我用fieldtypes简单文本而不是整数值.因为它似乎很容易在代码级别阅读.

class FormView(MethodView):
    def get(self):
        class DynamicForm(wtforms.Form): pass

        dform = main.models.Form.objects.get(name="name2")
        name = dform.name
        for f in dform.fields:
            print f.label
            setattr(DynamicForm , f.label, self.getField(f))

        d = DynamicForm() # Dont forget to instantiate your new form before rendering
        for field in d:
            print field # you can see html output of fields

        return render_template("customform.html", form=d)

    def getField(self, field): 
        if field.fieldtype == "text": 
            return TextField(field.label)
        if field.fieldtype == "password":
            return PasswordField(field.label)
        # can extend if clauses at every new fieldtype

一个简单的表单渲染jinja模板'forms.html'

{% macro render(form) -%}
<fieldset>
{% for field in form %}
{% if field.type in ['CSRFTokenField', 'HiddenField'] %}
  {{ field() }}
{% else %}
  <div class="form-group {% if field.errors %}error{% endif %}">
    {{ field.label }}
    <div class="input">
      {% if field.name == "body" %}
        {{ field(rows=10, cols=40) }}
      {% else %}
        {{ field() }}
      {% endif %}
      {% if field.errors or field.help_text %}
        <span class="help-inline">
        {% if field.errors %}
          {{ field.errors|join(' ') }}
        {% else %}
          {{ field.help_text }}
        {% endif %}
        </span>
      {% endif %}
    </div>
  </div>
{% endif %}
{% endfor %}
</fieldset>
{% endmacro %}

和customform.html是这样的

{% extends "base.html" %}
{% import "forms.html" as forms %}

{% block content %}
{{ forms.render(form) }}
{% endblock %}