Flask WTForms -- 自定义字段标志

Question

我构建了一个自定义验证器，用于检查数据库中是否存在用户输入。现在，我想添加一个自定义字段标志，如果验证不成功(无需重新呈现 html(，则会弹出该标志，类似于 InputRequired 验证器中的"必需"标志。

这是我的验证器：

class ProjectExists(object):
field_flags = ('project_not_exists', )   # need the custom flag here
def __init__(self, project_code=None, message=None):
self.project_code = project_code
self.message = message
self.conn, self.cur = connect_db()

def __call__(self, form, field):
code = field.data
self.cur.execute("SELECT 1 FROM database WHERE project_code = '{}'".format(code))
code_check = self.cur.fetchall()
if not code_check:
if self.message is None:
self.message = field.gettext('Project code {} does not exists!'.format(code))
raise StopValidation(self.message)

以下是 InputRequired 验证程序的源代码以供参考：

class InputRequired(object):
field_flags = ('required', )
def __init__(self, message=None):
self.message = message

def __call__(self, form, field):
if not field.raw_data or not field.raw_data[0]:
if self.message is None:
message = field.gettext('This field is required.')
else:
message = self.message
field.errors[:] = []
raise StopValidation(message)

感谢您的帮助！

Answer 1

让它与 Parsley 一起工作，检查现有端点是否存在项目代码。

WTForm：

class ViewForm(FlaskForm):
project_code = StringField('Project Code',
render_kw={'required':"", 'data-parsley-project-check':""})

JavaScript：

$(function () {
Parsley.addValidator('projectCheck', {
validateString: function(value) {
console.log("validating")
var send = {
id: value,
}
var url = '/projects/'
return $.getJSON(url, send, function(data) {
}).then(function(json) {
if (!json['features']) {
return $.Deferred().reject()
}
})
},
messages: {
en: 'Project code does not exist!'
}
})})