angular.js - How to implement linkage and post in angularjs?

Question

Recently I am using AngularJs to write a pull-down linkage, but I am stuck on the display of the second drop-down box value and the linkage value post. I hope you can help me

Question:

• How to display the value of the second drop-down box

• How to deal with the value after post submission? Now the value after the post of the first drop-down box is object:3, how to convert it into the value in json

html code:

<p id="login" ng-app='angular_post_demo' ng-controller='sign_up'>
    <input type="text" size="40" ng-model="email">            
    <br>
    <input type="password" size="40" ng-model="password">
    <br>
    <select ng-options="universit.uni for universit in arr" ng-model="university"></select>
    <br>
    <select ng-options="student for university in arr" ng-model="student"></select>
    <br>
    <button ng-click="check_credentials()">Login</button>
    <br>
    <span id="message"></span>
</p>

js code:

    var app = angular.module('angular_post_demo', []);
    app.controller('sign_up', function($scope, $http) {
        $scope.arr = [{
            "uni": "TS",
            "stu": ["Tom", "HHH", "KKK"]
        }, {
            "uni": "SDU",
            "stu": ["AA", "BBB"]
        }, {
            "uni": "SDUT",
            "stu": ["CCC", "DD"]
        }];
        $scope.university = $scope.arr[0];
        $scope.check_credentials = function() {
            document.getElementById('message').textContent = "";
            var request = $http({
                method: "post",
                url: window.location.href + "res.php",
                data: {
                    email: $scope.email,
                    pass: $scope.password,
                    university: $scope.university
                    // student: $scope.student
                }
            });
            request.success(function(data) {
                document.getElementById('message').textContent = data;
            });
        }
    });

Answer 1

• university’s select plus ngchange trigger

• Post object post-processing depends on your language