How can I handle file uploads in Flask using WTForms?

How can I handle file uploads in Flask using WTForms?

You can handle file uploads in Flask using the Flask-WTF extension, which integrates WTForms with Flask. First, you'll need to create a form class that includes a file field.

What does the form class look like?

Here's a simple example:

from flask_wtf import FlaskForm
from wtforms import FileField, SubmitField
from wtforms.validators import DataRequired

class UploadForm(FlaskForm):
    file = FileField('File', validators=[DataRequired()])
    submit = SubmitField('Upload')

How do I process the uploaded file in my route?

In your route, you can check if the form is submitted and validate it. Then, you can save the file like this:

@app.route('/upload', methods=['GET', 'POST'])
def upload():
    form = UploadForm()
    if form.validate_on_submit():
        file = form.file.data
        file.save(f'static/uploads/{file.filename}')
        return 'File uploaded successfully!'
    return render_template('upload.html', form=form)