Whether the backend user name exists validation | Show based Ajax when Mouse loses focus | Django Development

2. In the user name location, the mouse leaves the lost focus, uses AJAX to detect whether the user name exists, and displays2.1find the JS file of the checksum front-end input function check_user_name () {var len= $('#user_name'). val (). length; if(len<5| | Len>20)            {                $('#user_name'). Next (). HTML ('Please enter a 5-20-character user name')                $('#user_name'). Next (). Show (); Error_name=true; }            Else            {                //after the verification of the front-end format is successful, add a mouse to lose focus, to determine whether the user name exists;//through the AJAX request view, Jsonresponse returns the judgment result;Ajax Get Methods 3 parameters: 1. Access view; 2. Parameters to be carried by the request; 3. Success execution function after successful;//parameters in the execution function: data is the dictionary returned by the view Jsonresponse; $.get ('/users/check_useranme/', {'username': $('#user_name'). Val ()}, function (data) {//Displays the judging information according to the Returned judgment information .if(Data.ret = = 1){                        $('#user_name'). Next (). HTML ('User name exists'). Show (); Error_name=true; }                    Else{                        $('#user_name'). Next (). Hide (); Error_name=false;            }                }); }    2.2view functions for validationdefCheck_username (Request):#If the user existsUsername = post.get (Request,'username')            ifModels. User.objects.get (user_name=username):returnJsonresponse ({'ret': 1})            Else:                returnJsonresponse ({'ret': 0})

Whether the backend user name exists validation | Show based Ajax when Mouse loses focus | Django Development