I. installation
pip3 install wtforms
II. Simple Use
1. Create flask objects
from flask import Flask, render_template, request, redirect from wtforms import Form from wtforms.fields import simple from wtforms import validators from wtforms import widgets app = Flask(__name__, template_folder='templates') app.debug = True
II. Generating form Components
class LoginForm(Form):
# Fields (which contain regular expressions)
name = simple.StringField(
label='User name', #Form form label
validators=[ #Some Conditions for Filtration
validators.DataRequired(message='User name cannot be empty.'),
validators.Length(min=6, max=18, message='User name length must be greater than%(min)d And less than%(max)d')
],
widget=widgets.TextInput(), # Plug-ins displayed on the page
render_kw={'class': 'form-control'} #The class name displayed on the form pageThree. Routing
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'GET':
form = LoginForm() #Generate form objects
return render_template('login.html', form=form) #form object rendering
else:
form = LoginForm(formdata=request.form)
if form.validate(): #form checking
print('The data submitted by the user is validated by the format, and the value submitted is:', form.data)
else:
print(form.errors)
return render_template('login.html', form=form)
if __name__ == '__main__':
app.run()4. Page Rendering
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>Sign in</h1>
<form method="post">
<p>{{form.name.label}} {{form.name}} {{form.name.errors[0] }}</p>
<p>{{form.pwd.label}} {{form.pwd}} {{form.pwd.errors[0] }}</p>
<input type="submit" value="Submission">
</form>
</body>
</html>III. Relevant attributes
1.field field field
WTForms supports HTML fields:
| Field type | Explain |
|---|---|
| StringField | Text field, equivalent to the input tag of type text |
| TextAreaField | Multi-line text field |
| PasswordField | Password text field |
| HiddenField | Hidden text fields |
| DateField | Text field, value in datetime.date format |
| DateTimeField | Text field, value in datetime.datetime format |
| IntegerField | Text field with integer value |
| DecimalField | Text field, value decimal.Decimal |
| FloatField | Text field with floating point value |
| BooleanField | Check boxes with values of True and False |
| RadioField | A set of radio boxes |
| SelectField | Drop-down list |
| SelectMultipleField | Drop-down list, multiple values can be selected |
| FileField | File upload field |
| SubmitField | Form submission button |
| FormFiled | Embedding a form as a field into another form |
| FieldList | Subgroup field of specified type |
2.Validators Verifier
WTForms can support many form validation functions:
| Validation function | Explain |
|---|---|
| Verification is an e-mail address | |
| EqualTo | Compare the values of two fields; often used in situations where two keys are required for confirmation. |
| IPAddress | Verify IPv4 Network Address |
| Length | Verify the length of the input string |
| NumberRange | Verify that the input value is within the numerical range |
| Optional | Skip other validation functions without input values |
| DataRequired | Ensure that there is data in the field |
| Regexp | Validate input values using regular expressions |
| URL | Verify url |
| AnyOf | Ensure that input values are in the list of optional values |
| NoneOf | Ensure that input values are not in the optional list |
3. Field parameters
| Parameter name | introduce |
|---|---|
| label | Field alias, which can be displayed in the page by field. label |
| validators | Validation Rule List |
| filters | Perchlorinator list for filtering submitted data |
| description | Description information, usually used to generate help information |
| id | Represents the position of the field when the form class is defined. Usually you don't need to define it. By default, it will be sorted in the order of definition. |
| default | Default value |
| widget | html plug-in, through which you can override the default plug-in, more through user customization |
| render_kw | Customize html properties |
| choices | Options for Check Types |
4. Local hook
#In the form class
def validate_Field name(self, field):
#self.data obtains a dictionary-like format for global fields
#self.data ['field'], you can get any field in the global
#Value of the current field of field.data
#There is no need to return a value, and errors should be thrown if there are unsatisfactory situations.
#If you have two passwords, there are two situations.
# raise validators.ValidationError("Inconsistent passwords") # Continue subsequent validation
# raise validators.StopValidation("Inconsistent passwords") # No further follow-up validation5. Modify the value without changing the model
#In the form class
def __init__(self, *args, **kwargs):
super(RegisterForm, self).__init__(*args, **kwargs)
self.Field name.choices = ((1, 'Basketball'), (2, 'Football'), (3, 'Badminton'))4. Written templates
from flask import Flask, render_template, request, redirect
from wtforms import Form
from wtforms.fields import core
from wtforms.fields import html5
from wtforms.fields import simple
from wtforms import validators
from wtforms import widgets
app = Flask(__name__, template_folder='templates')
app.debug = True
class RegisterForm(Form):
name = simple.StringField(
label='User name',
validators=[
validators.DataRequired()
],
widget=widgets.TextInput(),
render_kw={'class': 'form-control'},
default='cxw'
)
pwd = simple.PasswordField(
label='Password',
validators=[
validators.DataRequired(message='Password cannot be empty.')
],
widget=widgets.PasswordInput(),
render_kw={'class': 'form-control'}
)
pwd_confirm = simple.PasswordField(
label='Repeat password',
validators=[
validators.DataRequired(message='Duplicate password cannot be empty.'),
validators.EqualTo('pwd', message="Two inconsistent password input")
],
widget=widgets.PasswordInput(),
render_kw={'class': 'form-control'}
)
email = html5.EmailField(
label='mailbox',
validators=[
validators.DataRequired(message='Mailbox cannot be empty.'),
validators.Email(message='Error in mailbox format')
],
widget=widgets.TextInput(input_type='email'),
render_kw={'class': 'form-control'}
)
gender = core.RadioField(
label='Gender',
choices=(
(1, 'male'),
(2, 'female'),
),
#The first value of the choices tuple above is the int type.
#If the top is (`1', `male') and (`2', `female'), then the coerce below does not need to be written.
coerce=int # "1" "2"
)
#Here is the radio box.
city = core.SelectField(
label='City',
choices=(
('bj', 'Xie'),
('sh', 'Xie'),
)
)
#Here is the multi-check box.
hobby = core.SelectMultipleField(
label='hobby',
choices=(
(1, 'Basketball'),
(2, 'Football'),
),
coerce=int
)
#Here is the checkbox with multiple choices
favor = core.SelectMultipleField(
label='Like',
choices=(
(1, 'Basketball'),
(2, 'Football'),
),
widget=widgets.ListWidget(prefix_label=False),
option_widget=widgets.CheckboxInput(),
coerce=int,
default=[1, 2]
)
#Here we can change the value.
def __init__(self, *args, **kwargs):
super(RegisterForm, self).__init__(*args, **kwargs)
self.favor.choices = ((1, 'Basketball'), (2, 'Football'), (3, 'Badminton'))
def validate_pwd_confirm(self, field):
"""
//Customize the pwd_confirm field rule, for example: Is it consistent with the PWD field?
:param field:
:return:
"""
# At the beginning of initialization, all the values in self.data already exist
if field.data != self.data['pwd']:
# raise validators.ValidationError("Inconsistent passwords") # Continue subsequent validation
raise validators.StopValidation("Inconsistent passwords") # No further follow-up validation
@app.route('/register', methods=['GET', 'POST'])
def register():
if request.method == 'GET':
#Here you can pass default values
form = RegisterForm(data={'gender': 2,'hobby':[1,]}) # initial
return render_template('register.html', form=form)
else:
form = RegisterForm(formdata=request.form)
if form.validate():
print('The data submitted by the user is validated by the format, and the value submitted is:', form.data)
else:
print(form.errors)
return render_template('register.html', form=form)
if __name__ == '__main__':
app.run()