使用flask-wtf和sqlalchemy生成动态表单 [英] Generate a dynamic form using flask-wtf and sqlalchemy

问题描述

我有一个 web 应用程序，它允许用户创建自己的字段，以便稍后在表单中呈现.

我有一个像这样的模型 Formfield:

class Formfield(db.Model):id = db.Column(db.Integer, primary_key = True)form_id = db.Column(db.Integer, db.ForeignKey('formbooking.id'))标签 = 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 放在这里?答案 = db.Column(db.String)required = db.Column(db.Boolean, nullable = False, default = False)订单 = db.Column(db.Integer)字段类型 = db.Column(db.Integer)

我用来表示一个字段，不管是什么类型的(复选框、输入、未来更多).

如您所见，每个字段都有一个到 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 fieldtype.

我想一个解决方案是以某种方式将 form_id 传递给我的 Form 类中的一个函数.

我不知道该怎么做或在哪里寻找解决方案.

任何帮助将不胜感激！

解决方案

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

你必须在视图函数中创建一个动态表单，获取你想要获取的表单字段，并迭代每个字段来构造这个表单对象.我用于字段类型的简单文本而不是整数值.因为它在代码级别看起来很容易阅读.

class FormView(MethodView):定义获取(自我):类 DynamicForm(wtforms.Form):通过dform = main.models.Form.objects.get(name="name2")名称 = dform.name对于 dform.fields 中的 f:打印 f.labelsetattr(DynamicForm, f.label, self.getField(f))d = DynamicForm() # 在渲染之前不要忘记实例化你的新表单对于 d 中的字段:打印字段#可以看到字段的html输出return render_template("customform.html", form=d)def getField(self, field):如果 field.fieldtype == "text":返回 TextField(field.label)如果 field.fieldtype == 密码":返回 PasswordField(field.label)# 可以在每个新的字段类型上扩展 if 子句

对于一个简单的表单渲染 jinja 模板 'forms.html'

{% 宏渲染(form) -%}<字段集>{% 用于表单 %} 中的字段{% if field.type in ['CSRFTokenField', 'HiddenField'] %}{{ 场地() }}{％ 别的 ％}<div class="form-group {% if field.errors %}error{% endif %}">{{ field.label }}<div class="输入">{% if field.name == "body" %}{{ 字段(行 = 10，列 = 40)}}{％ 别的 ％}{{ 场地() }}{％ 万一 ％}{% if field.errors 或 field.help_text %}<span class="help-inline">{% if field.errors %}{{ field.errors|join(' ') }}{％ 别的 ％}{{ field.help_text }}{％ 万一 ％}</span>{％ 万一 ％}

{％ 万一 ％}{% 结束为 %}</fieldset>{% 宏 %}

而customform.html是这样的

{% 扩展 "base.html" %}{% import "forms.html" as forms %}{% 块内容 %}{{ forms.render(form) }}{% 结束块 %}

I have a webapp that allows users to create their own fields to be rendered in a form later on.

I have a model Formfield like so:

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) 

that I use to represent a field, whatever the kind (checkbox, input, more in the future).

As you can see, every field has a FK to a form_id.

I’m trying to generate a dynamic form for a given form_id. The catch is that I need to determine the type of field to render for every Formfield. So I also need to process the fieldtype at some point.

I guess a solution would be to somehow pass the form_id to a function in my Form class.

I have no clue how to do it or where to look for a solution.

Any help would be very appreciated!

解决方案

I think I managed to create dynamic forms with the idea from here https://groups.google.com/forum/#!topic/wtforms/cJl3aqzZieA

you have to create a dynamic form at view function, fetch the form field you want to get, and iterate every field to construct this form object. I used for fieldtypes simple text instead of integer values. Since it seems easy to read at code level.

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

for a simple form render jinja template '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 %}

and customform.html is like this

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

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

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