FileAllowed不显示错误消息 [英] FileAllowed does not display an error message
问题描述
我正在使用WTForms.我正在对文件上传应用验证，并将其限制为jpg，png和pdf格式.但是，如果我输入不正确，则不会出现错误消息.
我遵循了本教程
- 获取有效的文件格式(.png格式)
requirements.txt :
Click == 7.0烧瓶== 1.0.3烧瓶-WTF == 0.14.2itsdangerous == 1.1.0Jinja2 == 2.10.1MarkupSafe == 1.1.1pkg-resources == 0.0.0Werkzeug == 0.15.4WTForms == 2.2.1 运行应用程序:
export FLASK_APP = app.py出口FLASK_ENV =发展烧瓶运行 参考:
I am using WTForms. I am applying validation on file upload and restricted it to jpg,png and pdf format only. however if i give an incorrect input, no error message appears.
I followed this tutorial https://flask-wtf.readthedocs.io/en/stable/form.html
photo = FileField('photo', validators=[
FileRequired(),
FileAllowed(['png', 'pdf', 'jpg'], "wrong format!")
])
By default, flask-wtf does not show any error message if validation fails.
Error messages can be caught and shown for each individual field or for all fields together.
Here is an example of file upload with validation in flask-wtf.
Folder structure:
.
├── app.py
├── forms.py
├── requirements.txt
└── templates
└── upload.html
app.py:
from flask import Flask, render_template
from forms import FileUploadForm
app = Flask(__name__)
app.secret_key = 'learnflask'
@app.route('/upload', methods=['GET', 'POST'])
def upload():
form = FileUploadForm()
if form.validate_on_submit():
f = form.photo_or_pdf_file.data
return f.filename
return render_template('upload.html', form=form)
forms.py:
from flask_wtf import FlaskForm
from wtforms import SubmitField
from flask_wtf.file import FileField, FileAllowed, FileRequired
class FileUploadForm(FlaskForm):
photo_or_pdf_file = FileField('photo', validators=[
FileRequired(),
FileAllowed(['png', 'pdf', 'jpg'], "wrong format!")
])
submit = SubmitField('Upload')
templates/upload.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>login</title>
<style>
.validation_error{
color: red;
}
</style>
</head>
<body>
<form method="POST" enctype="multipart/form-data">
{{ form.csrf_token }}
{{ form.photo_or_pdf_file.label }}<br>{{ form.photo_or_pdf_file }}
<span class="validation_error">{{ ', '.join(form.photo_or_pdf_file.errors) }}</span><br>
{{ form.submit }}<br>
</form>
</body>
</html>
Output:
- For invalid file format (audio file):
- For valid file format (.png format)
requirements.txt:
Click==7.0
Flask==1.0.3
Flask-WTF==0.14.2
itsdangerous==1.1.0
Jinja2==2.10.1
MarkupSafe==1.1.1
pkg-resources==0.0.0
Werkzeug==0.15.4
WTForms==2.2.1
Running the application:
export FLASK_APP=app.py
export FLASK_ENV=development
flask run
Reference:
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