flask修改flask_wtf使其支持json数据的validation验证

flask默认是前后端不分离策略,前端通过flask+wtf表单来传递post,put...等数据.

现在前后端分离是趋势,那么对flask进行一定的修改,变为前后端分离,在前端页面中请求后端,那么请求的格式那么必然会有使用json传递数据,然而flask_wtf默认只支持form表单,那么对改动支持json

代码如下:

 # coding=utf-8

 from flask import request
 from wtforms import Form
 from OnlineClassroom.app.err.JsonValidateErr import JsonValidateErr

 # request data 基础验证器
 class RequestBaseForm(Form):
     # 解析请求参数
     def __init__(self):
         # todo 做个处理,如果请求进来的请求时form参数则else,如果是json则进行下列操作
         if "application/json" in request.headers.get("Content-Type"):
             data = request.get_json(silent=True)
             args = request.args.to_dict()
             super(RequestBaseForm, self).__init__(data=data, **args)
         else:
             # application/x-www-form-urlencoded    or    multipart/form-data
             data = request.form.to_dict()
             args = request.args.to_dict()
             super(RequestBaseForm, self).__init__(data=data, **args)

     # 对验证错误的参数抛出异常
     def validate_for_api(self):
         valid = super(RequestBaseForm, self).validate()
         if not valid:
             # todo 这里做一个返回,code,msg,data 错误返回  ???
             raise JsonValidateErr("field is require?")

         return self

根据请求header中content-type来对数据解析,调用wtfforms的Form父类方法__init__将解析过后的参数给予父类的属性,其中自定义方法validate_for_api调用父类的验证方法validate()由父类来确定是否存在与准确

form表单模型:

 # coding=utf-8

 from .JsonBaseValidate import RequestBaseForm
 from wtforms import StringField,Form
 from wtforms.validators import DataRequired,Length

 class Testform(RequestBaseForm):
     username = StringField("username",validators=[DataRequired(),Length(min=2,max=20)])

---

一个简单的测试,路由代码如下:

 @user.route("/index",methods=["GET","POST"])
 def xx():
     req = Testform()
     type = request.headers.get("Content-Type")
     if req.validate_for_api():
         return "requset username.data {} >> request context-type {}".format(req.username.data,type)
     return "request validate failds..."

这是json请求,不要忘记在header中将content-type的选项改为applocation/json

这是form-data和form-urlencoded