验证 WTF Flask 表单输入值

Question

我的烧瓶应用程序中有以下表格。我想确保输入值实际上是一个整数，并且如果在 token > k 这里输入的值 k 可以是某个数字，它会向屏幕显示一条错误消息。 IntegerField 似乎没有强制执行整数值，例如，如果用户输入 2.3，它会将其传递给我的函数，该函数失败，因为它需要一个整数。

这种类型的错误消息是否会出现在表单中，或者一旦值从表单传递到服务器，我是否需要在我的烧瓶应用程序中对其进行编程？

class Form(FlaskForm):
    token = IntegerField('Token Size', [DataRequired()], default = 2)          
    submit = SubmitField('Submit')

编辑 根据下面的评论，用我修改后的表格和路线更新它

class Form(FlaskForm):
    token = IntegerField('Token Size', validators=[DataRequired(), NumberRange(min=1, max=10, message='Something')], default = 2)
    ngram_method = SelectField('Method', [DataRequired()],
        choices=[('sliding', 'Sliding Window Method'),
                 ('adjacent', 'Adjacent Text Method')]) 
    rem_stop = BooleanField('Remove Stop Words', render_kw={'checked': True})
    rem_punc = BooleanField('Remove Punctuation', default = True)
    text2use = SelectField('Text To Use for Word Tree', [DataRequired()],
        choices=[('clean', 'Clean/Processed Text'),
                 ('original', 'Original Text String')])
    pivot_word = TextField('Pivot Word for Word Tree', [DataRequired()])                
    submit = SubmitField('Submit')

以及表单的使用路径

@word_analyzer.route('/text', methods=('GET', 'POST'))
def text_analysis():
    form = Form()
    result = '<table></table>' 
    ngrams = '<table></table>' 
    orig_text = '<table></table>' 
    text = ""
    if request.method == 'POST':
        tmp_filename = tempfile.gettempdir()+'\\input.txt'
        if request.files:
            txt_upload = request.files.get('text_file')
            if txt_upload:
                f = request.files['text_file']
                f.save(tmp_filename)
        if os.path.exists(tmp_filename):
            file = open(tmp_filename, 'r', encoding="utf8") 
            theText = [line.rstrip('\n') for line in file]
            theText = str(theText)
            token_size = form.token.data
            stops = form.rem_stop.data
            punc = form.rem_punc.data
            ngram_method = form.ngram_method.data
            text_result = text_analyzer(theText, token_size = token_size, remove_stop = stops, remove_punctuation = punc, method = ngram_method)
            result = pd.DataFrame.from_dict(text_result, orient='index', columns = ['Results'])[:-3].to_html(classes='table table-striped table-hover', header = "true", justify = "center")
            ngrams = pd.DataFrame.from_dict(text_result['ngrams'], orient='index', columns = ['Frequency']).to_html(classes='table table-striped table-hover', header = "true", justify = "center")
            if form.pivot_word.data == None:
                top_word = json.dumps(text_result['Top Word'])
            else:
                top_word = json.dumps(form.pivot_word.data)
            if form.text2use.data == 'original':
                text = json.dumps(text_result['original_text'])
            else:
                text = json.dumps(text_result['clean_text'])
            if form.validate_on_submit():   
                return render_template('text.html', results = [result], ngrams = [ngrams], form = form, text=text, top_word = top_word) 
    return render_template('text.html', form = form, results = [result],ngrams = [ngrams], text=text, top_word='') 

Answer 1

使用来自wtforms.validators.NumberRange 的NumberRange 验证器。您可以将可选的最小值和最大值与错误消息一起传递。更多信息here

更新

# Form Class
class Form(FlaskForm):
    token = FloatField('Token Size', validators=[DataRequired(), NumberRange(min=1, max=10, message='Something')])

# Route
if form.validate_on_submit():
    print(form.name.data)

这是一个应该可以使用的示例，请确保您的表单类字段看起来相似，并且在您的路线中使用form.validate_on_submit():。