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python - 覆盖 FlaskForm.validate() 不会让 POST 请求通过

问题描述

概括

我正在尝试存储除字符串值之外的 3 个浮点值；但在此之前，我想通过相互检查来验证 FloatFields。

它们是 3 个指标 - 好、平均和差，我已将验证器.NumberRange 包含在 [-1, 1] 中。这工作正常，所以如果我输入超出范围，默认错误消息会显示在我的模板中，在 -1 和 1 内输入

现在我必须在将它们添加到 db 之前验证 Good、Average 和 Poor 指标是按降序排列的。

代码

形式：

from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField, FloatField
from wtforms.validators import DataRequired, Length, ValidationError, NumberRange
from .models import Crop


# FORMS RENDERED TO CORRESPONDING WEB TEMPLATES IN DEFINED VIEWS

class CropForm(FlaskForm):
    crop_name = StringField("Crop Name", validators=[DataRequired(), Length(max=80)])
    good_threshold = FloatField("Good", validators=[DataRequired(), NumberRange(min=-1, max=1)])
    average_threshold = FloatField("Average", validators=[DataRequired(), NumberRange(min=-1, max=1)])
    poor_threshold = FloatField("Poor", validators=[DataRequired(), NumberRange(min=-1, max=1)])
    submit = SubmitField("Submit")

    def validate_crop_name(self, crop_name):  # IGNORE THIS
        crop = Crop.query.filter_by(crop_name=str(crop_name.data).casefold().replace(" ", "").capitalize()).first()
        if crop:
            raise ValidationError("Crop with the name already exists")

    def validate(self, *args, **kwargs):
        super(CropForm, self).validate(*args, **kwargs)
        good_input = self.good_threshold.raw_data
        average_input = self.average_threshold.raw_data
        poor_input = self.poor_threshold.raw_data
        if good_input < average_input:
            self.average_threshold.errors.append("Average cannot be more than Good Indicator")
        if good_input < poor_input:
            self.poor_threshold.errors.append("Poor cannot be more Good indicator")
        if average_input < poor_input:
            self.poor_threshold.errors.append("Poor cannot be more Average indicator")

当我在 CropForm FORM 中删除/注释 validate() 块时，我可以将未验证的值（如 Good=0.5、Average=0.8、Poor=0.9）发送到数据库，这是我不喜欢的，因为它们不是降序排列

当我保持原样/取消注释时，CropForm FORM 中的 validate() 块，发送可接受的值，如 Good=0.9、Average=0.8、Poor=0.5，然后我点击模板上的提交按钮，它根本没有发送值 t db

模型：

class Crop(db.Model):
    id = db.Column(db.Integer, primary_key=True, unique=True, nullable=False)
    crop_name = db.Column(db.String, unique=True, nullable=False)
    good_threshold = db.Column(db.Float)
    average_threshold = db.Column(db.Float)
    poor_threshold = db.Column(db.Float)


    def __repr__(self):
        return f"{self.id}.{self.crop_name}"

看法：

@app.route("/crops", methods=["POST", "GET"])
    def crops():
        form = CropForm()
        if form.validate_on_submit():
            crop_info = Crop(crop_name=str(form.crop_name.data).casefold().replace(" ", "").capitalize(),
                             good_threshold=form.good_threshold.data,
                             average_threshold = form.average_threshold.data,
                             poor_threshold=form.poor_threshold.data)
            db.session.add(crop_info)
            db.session.commit()
            flash(f"Thresholds added, check record #{crop_info.id}", 'success')
            return redirect(url_for('crops'))
        records = Crop.query.order_by(Crop.id)
        return render_template('crop_thresholds.html', title="Crop Thresholds", form=form, records=records)

标签： pythonflaskwtforms

解决方案

您可以尝试将您的验证功能替换为这样的东西

def validate(self, *args, **kwargs):
    super(CropForm, self).validate(*args, **kwargs)
    good_input = self.good_threshold.raw_data
    average_input = self.average_threshold.raw_data
    poor_input = self.poor_threshold.raw_data
    all_okay = True
    if good_input < average_input:
        self.average_threshold.errors.append("Average cannot be more than Good Indicator")
        all_okay = False
    if good_input < poor_input:
        self.poor_threshold.errors.append("Poor cannot be more Good indicator")
        all_okay = False
    if average_input < poor_input:
        self.poor_threshold.errors.append("Poor cannot be more Average indicator")
        all_okay = False
    return all_okay

这个想法是 validate 函数将根据是否返回来确定验证是否应该True成功False。因此，如果任何 if 语句失败，all_okay则False验证失败。否则验证应该通过并且您应该能够继续输入if form.validate_on_submit():代码块

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