tornado中form表单验证详解

#!/usr/bin/env python
# _*_ coding:utf-8 _*_
import tornado.web
import tornado.ioloop
import re

class BaseForm(object):
    def check_valid(self, handle):
        flag = True
        error_message_dict = {}
        success_value_dict = {}

        for key, regular in self.__dict__.items():
            input_value = handle.get_argument(key)
            # val = re.match(regular, input_value)
            # 把验证方法封装到IPField的对象中
            regular.validate(key, input_value)
            if regular.is_valid:
                success_value_dict[key] = regular.value
            else:
                error_message_dict[key] = regular.error
                flag = False
        return flag, success_value_dict, error_message_dict
# 总结：客户端把数据post到服务器端，触发handler的post函数，首先实例化MainForm这个类，得到
# 其对象obj。然后obj调用check_valid(self)方法，并把IndexHandler这个类的对象作为参数传进去，
# check_valid是每个Form都具有的方法，所以抽象出一个BaseForm类，让其他Form类都继承这个类，
# 因此其他Form类的对象也可以调用check_valid方法，当obj调用该方法，先循环obj对象所被封装类的
# 属性，得出一个包含ip，host属性名和IPField，HOSTField的对象的一个字典，对应的是key和regular，
# 以IPField为例，regular就是IPField实例化后的对象，一开始我们是在check_valid这个方法里直接
# 验证所有输入的值，现在转移到IPField的方法里去验证，现在调用check_valid是间接的去验证输入的值，
# 也就是regular.validate(key, input_value)，这里我觉得关键是self.__dict__，所有都是围绕它
# 的键值对来操作，只不过regular由原先的正则表达式换成类实例化的对象，而正则表达式也封装到这个类
# 里面，并且这个类的对象通过调用这个类的方法来验证客户端输入的信息

class MainForm(BaseForm):
    def __init__(self):
        self.ip = IPField(required=True, error_dict={"required": "别闹", "valid": "格式错误"})
        self.favor = ChechBoxFiled(required=True, error_dict={'required': "复选框不能为空"})

class IPField():
    REGULAR = "(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"

    def __init__(self, error_dict=None, required=True):
        self.error_dict = {}
        if error_dict:
            self.error_dict.update(error_dict)
        self.required = required
        self.error = None
        self.is_valid = False
        self.value = None

    def validate(self, name, input_value):
        if not self.required:
            # 如果输入的值可以为空，
            self.is_valid = True
            self.value = input_value

        else:
            # 如果要求输入的值不能为空
            if not input_value.strip():
                # 如果我输入的值是空值，然后我就去取error_dict里面required对应的值
                if self.error_dict.get("required", None):
                    # 如果在生成IPField对象的时候有初始化required的值，则应用该值
                    self.error = self.error_dict["required"]
                else:
                    # 否则，默认把ip is required赋值到self.error
                    self.error = "%s is required" % name
            else:
                # 如果我输入的值不是空值，那么我就要和正则表达式进行比较
                ret = re.match(IPField.REGULAR, input_value)
                if ret:
                    self.is_valid = True
                    # self.value = ret.group()
                    self.value = input_value
                else:
                    if self.error_dict.get("valid", None):
                        self.error = self.error_dict["valid"]
                    else:
                        self.error = "%s is invalid" % name

class ChechBoxFiled:

    def __init__(self, error_dict=None, required=True):
        # 封装了错误信息
        self.error_dict = {}
        if error_dict:
            self.error_dict.update(error_dict)

        self.required = required

        self.error = None  # 错误信息
        self.value = None
        self.is_valid = False

    def validate(self, name, input_value):
        """
        :param name: 字段名 favor
        :param input_value: 用户表单中输入的内容，列表None, [1,2]
        :return:
        """

        if not self.required:
            # 用户输入可以为空
            self.is_valid = True
            self.value = input_value
        else:
            if not input_value:
                if self.error_dict.get('required', None):
                    self.error = self.error_dict['required']
                else:
                    self.error = "%s is required" % name
            else:
                self.is_valid = True
                self.value = input_value

class IndexHandler(tornado.web.RequestHandler):
    def get(self, *args, **kwargs):
        self.render("index.html", error_dict=None)

    def post(self, *args, **kwargs):
        obj = MainForm()
        is_valid, success_dict, error_dict = obj.check_valid(self)
        if is_valid:
            print("success", success_dict)
        else:
            print("error", error_dict)
            self.render("index.html", error_dict=error_dict)

settings = {
    "template_path": "views",
    "static_path": "Statics",
    "static_url_prefix": "/Statics/",

}

application = tornado.web.Application([
    (r"/index", IndexHandler)
], **settings)

if __name__ == '__main__':
    application.listen(9001)
    tornado.ioloop.IOLoop.instance().start()