![](/img/trans.png)
[英]Python WTForms: How to dynamically set options of a SelectField in FieldList of FormFields?
[英]WTForm: FieldList with SelectField, how do I render?
我有这个订单表,允许我的用户创建订单。 一个订单由多个(producetype, quantity)
元组组成。 Producetype 应该以<select>
形式呈现,而数量可以只是一个输入。 应该动态添加生产类型的选择,因为这可能会改变。 目前,我已经用裸 html 写了这个
我想为此使用 WTForm,因为 WTForm 确实简化了我的代码。 但是,我无法这样做:
代码:
class OrderEntryForm(Form):
quantity = IntegerField('Quantity',
[validators.Required(), validators.NumberRange(min=1)])
# we will be dynamically adding choices
producetype = SelectField('Produce',
[validators.Required()],
choices=[])
class OrderForm(Form):
name = TextField('Crop', [validators.Length(min=3, max=60)])
due_date = DateField('Due Date', [validators.required()])
order_entries = FieldList(FormField(OrderEntryForm))
我有以下问题:
order_entries
字段?order = { name:hello, due_date:2014-06-18, order_entries:[ {producetype_id: 1, quantity: 2}, {producetype_id: 3, quantity: 4}] }
,如何填充我的具有正确OrderEntryForm
值的OrderForm
?如何将选项动态添加到 OrderForm 的 order_entries 字段
这取决于你的意思
如果您的意思是要在渲染后向表单添加行项目。 您必须使用 DOM 操作在客户端添加这些。 WTForms有一个命名约定来处理表单字段上的索引。 它只是name="<form-field)name>-<index>"
。 如果您使用遵循此约定的 javascript 添加名称, WTForms将知道如何在后端处理它。
如果你的意思是你想要一个动态的选择列表,那么你可以在实例化后迭代表单中的FieldList
。 您可以分配choices
任何可迭代的 2 元组。 在下面的示例中,我直接分配了它们,但它们也可以很容易地从存储中检索。
order_form = OrderForm()
for sub_form in order_form.order_entries:
sub_form.producetype.choices = [('2', 'apples'), ('2', 'oranges')]
如何使用正确的 OrderEntryForm 值填充我的 OrderForm?
您可以使用obj
关键字参数将对象直接绑定到表单。 WTForms足够智能,可以根据对象的属性动态构建表单。
from wtforms import Form, IntegerField, SelectField, TextField, FieldList, FormField
from wtforms import validators
from collections import namedtuple
OrderEntry = namedtuple('OrderEntry', ['quantity', 'producetype'])
Order = namedtuple('Order', ['name', 'order_entries'])
class OrderEntryForm(Form):
quantity = IntegerField('Quantity',
[validators.Required(), validators.NumberRange(min=1)])
# we will be dynamically adding choices
producetype = SelectField('Produce',
[validators.Required()],
choices=[
(1, 'carrots'),
(2, 'turnips'),
])
class OrderForm(Form):
name = TextField('Crop', [validators.Length(min=3, max=60)])
order_entries = FieldList(FormField(OrderEntryForm))
# Test Print of just the OrderEntryForm
o_form = OrderEntryForm()
print o_form.producetype()
# Create a test order
order_entry_1 = OrderEntry(4, 1)
order_entry_2 = OrderEntry(2, 2)
order = Order('My First Order', [order_entry_1, order_entry_2])
order_form = OrderForm(obj=order)
print order_form.name
print order_form.order_entries
上面的示例创建了一个示例Order
并将其提供给obj
关键字。 在渲染时,这将生成以下内容(无样式):
对于其他被SelectField
s + FieldList
s 难倒的人,这就是我使用SelectField
s 实现FieldList
的方式(受nsfyn55 的回答启发)。 这种方法基于 JSON 数据将任意数量的 SelectField 动态呈现到/home
路由。
路线(routes.py):
@app.route('/home', methods=['POST', 'GET'])
def home():
custom_metadata = data
select_metadata_form_list = SelectFormList()
select_metadata_form_list.select_entries = get_select_entries()
context = {
"select_metadata_form_list": select_metadata_form_list,
}
return render_template('home.html', **context)
表格(forms.py):
class SelectForm(FlaskForm):
select = SelectField("Placeholder", choices=[])
class SelectFormList(FlaskForm):
select_entries = FieldList(FormField(SelectForm))
模板( home.html
):
{% for select_form in select_metadata_form_list.select_entries %}
{{select_form.select.label}}: {{ select_form.select}}
{% endfor %}
辅助方法(app.py):
def get_select_entries():
"""
Converts custom metadata to a forms.SelectForm(), which can then be
used by SelectFormlist() to dynamically render select items.
:return: <forms.SelectForm object>
"""
select_data = get_select_data_from_custom_metadata()
select_data_labeled = get_labled_select_data(select_data=select_data)
all_select_items = []
for select_dict in select_data_labeled:
for k, v in select_dict.items():
select_id = uuid.uuid1() # allows for multiple selects
select_entry = SelectForm()
select_entry.select.label = k
select_entry.id = select_id
select_entry.select.choices = v
all_select_items.append(select_entry)
return all_select_items
def get_select_data_from_custom_metadata():
"""
[
{"Seniority": ["Intern", "Associate", "Senior"]}
]
:return: List of dictionaries containing key and list of select values
"""
type = "select"
select_data = []
custom_metadata = get_custom_metadata()
for field in custom_metadata["fields"]:
if field["type"] == type:
select_data.append({field["key"]: field["data_list"]})
return select_data
“数据” (custom_metadata.json):
{
"fields": [
{
"type": "text",
"key": "Position"
},
{
"type": "select",
"key": "Seniority",
"data_list": ["Intern", "Associate", "Senior", "Executive"]
},
{
"type": "select",
"key": "Company",
"data_list": ["Ford", "Chevy", "Toyota"]
},
{
"type": "select",
"key": "Team",
"data_list": ["Bucks", "Raptors", "Thunder"]
}
]
}
结果:
将SubmitField
添加到您的 to OrderForm
:
submit_something = SubmitField((u'Add something'))
然后从您的视图调用它,并使用append_entry
的方法FieldList
:
if form.submit_something.data:
form.order_entries.append_entry()
return render_template('yourtemplate.html', form=form)
希望有帮助!
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.