Question

我结合了 Flask-WTF 和 Flask-upload 来处理我的App上的文件上传。

我的软件包版本为：

Flask-Uploads==0.2.1
Flask-WTF==0.11
WTForms==2.1

这是我的代码段：

forms.py

from flask_wtf import Form
from flask_wtf.file import FileAllowed, FileRequired
from wtforms.fields import (StringField, SubmitField, FileField)
from wtforms.validators import InputRequired, Length
from app import photos

class AddCourseForm(Form):
    name = StringField('Course name', validators=[InputRequired(), Length(1, 100)])
    image = FileField('image', validators=[FileRequired(), FileAllowed(photos, 'Images only!')])
    submit = SubmitField('Add course')

这是上传代码的片段：

@operator.route('/add-course', methods=['GET', 'POST'])
def add_course():
    form = AddCourseForm()
    if form.validate_on_submit():
        course_name = form.name.data
        filename = photos.save(request.files['image'], name="courses/" + course_name + "_course.")
        course = Course(name=course_name, image=filename)
        db.session.add(course)
        db.session.commit()
        flash('Successfully added {} '.format(course.course_name()) + 'course', 'success')
        return redirect(url_for('operator.courses'))
    return render_template('main/operator/add_course.html', form=form)

但是，当我提交时，出现以下错误：

AttributeError: 'FileField' object has no attribute 'has_file'

然后，我尝试通过直接传递扩展名来遵循此documentation，而没有Flask-Upload：

image = FileField('image', validators=[FileRequired(), FileAllowed(['jpg', 'png'], 'Images only!')])

但是我仍然遇到同样的错误。

那么，我的代码有什么问题呢？请，任何帮助将不胜感激：）

Answer 1

您从wtforms库导入FileField：

from wtforms.fields import (StringField, SubmitField, FileField)

...，但是FileField.has_file()方法特定于Flask-WTF。

您需要将FileField中的flask_wtf.file添加到其他导入中。

您可以访问Flask-WTF.file.FileField here的API文档。

当前的实现（found here）是：

class FileField(_FileField):
    """Werkzeug-aware subclass of :class:`wtforms.fields.FileField`."""

    def process_formdata(self, valuelist):
        valuelist = (x for x in valuelist if isinstance(x, FileStorage) and x)
        data = next(valuelist, None)

        if data is not None:
            self.data = data
        else:
            self.raw_data = ()

    def has_file(self):
        """Return ``True`` if ``self.data`` is a
        :class:`~werkzeug.datastructures.FileStorage` object.
        .. deprecated:: 0.14.1
            ``data`` is no longer set if the input is not a non-empty
            ``FileStorage``. Check ``form.data is not None`` instead.
        """

        warnings.warn(FlaskWTFDeprecationWarning(
            '"has_file" is deprecated and will be removed in 1.0. The data is '
            'checked during processing instead.'
        ))
        return bool(self.data)

如您所见，该类继承自标准wtforms实现（在模块中名为_FileField），但对其进行了扩展以覆盖process_formdata()方法并添加has_file()方法。 / p>

还要注意，他们正在折旧该方法，建议您只检查该字段的data属性-它不完全是技术上的实现，因此您可以执行其操作来获得相同的功能：{ {1}}。

作为参考，这是wtforms bool(field.data)的实现：

FileField

...表明它没有除基类class FileField(Field): """Renders a file upload field. By default, the value will be the filename sent in the form data. WTForms **does not** deal with frameworks' file handling capabilities. A WTForms extension for a framework may replace the filename value with an object representing the uploaded data. """ widget = widgets.FileInput() def _value(self): # browser ignores value of file input for security return False上定义的方法之外的任何方法。

Flask-WTF'FileField'对象没有属性'has_file'

1 个答案: