经常使用 angularjs 中的 http 调用从 REST API 请求数据

Question

I am new to angularjs and D3. Here I am going to to implement real time line chart using D3. I am retrieving data from external REST API, by using angulrjs http call. But the problem is, I don't know how to request data frequently from the REST API using http call.

Answer 1

If you absolutely can't use web sockets then checkout $interval. https://docs.angularjs.org/api/ng/service/$interval

Basically this allows you to execute a function over and over again with a specified delay.

For example:

(function () {
'use strict';
angular
    .module('app')
    .controller('TestController', TestController);

TestController.$inject = ['$interval'];

function TestController($interval) {
    var vm = this;

    //Perform doSomething every 10000 ms
    $interval(doSomething, 10000);

    function doSomething() {
         //some logic here
    }       
}

})();

In the above code the function doSomething will be called every 10000ms.

So you in your case you can place your request inside doSomething and update your scope with the response from your rest api.

NB: This works but is not necessarily the best solution. Something like Signal R with websockets would be a better solution.