title: Realtime graph in D3.js and javascript
body: <p>I have a question and I know it might be silly!
  I have a Json file and I want to create a dynamic graph with javascript and D3.js in which x axis updated with the time and on y axis we have the values coming from the value field of json file. As you can see the time in this file is past so I want to have the current time of the system when the value is read, so I always have the updated time not the past time of this json file.</p>
  
  <pre><code>"values": [
          {
              "time": 124123213,
              "value": 500
          },
          {
              "time": 124123214,
              "value": 600
          },
  ]
  </code></pre>
  
  <p>My question is that how is it possible to have a DYNAMIC graph based on this json file. Since the values in this json file is limited and when it ends the graph stands still. Is it any way to generate it dynamically to make the graph updates forever?  Should I do any ajax or any extra thing? Does anyone know any similar example in javascript and D3.js? </p>
  
  <p>Thanks</p>