react_ajax.js

class Detail extends React.Component{

  constructor(props){
		super(props);

    this.state = {
      commits: [],
      mode: "commits",
      forks: [],
      pulls: []
    };

    this.ajaxCall = this.ajaxCall.bind(this);
    this.renderForks = this.renderForks.bind(this);
	  
	  /*
var self = this;

    this.ajaxCall('https://api.github.com/repos/facebook/react/commits', 'commits', function(response){
      self.setState = {
        commits: response,
        mode: "commits",
        forks: [],
        pulls: []
      };
      console.log("sha from commits in constructor: " + response.commits[0].sha);
    });
*/
  }

  ajaxCall(link, mode, callback){
    ajax.get(link)
    .end((error, response) => {
      if (!error && response) {
        var newStateObj = {};
        newStateObj[mode] = response.body
        newStateObj.mode = mode;
        callback(newStateObj);
      } else {
        console.log('There was an error fetching from GitHub', error);
      }
    });
  }
  
  renderForks(){
    var that = this;
    this.ajaxCall('https://api.github.com/repos/facebook/react/forks', 'forks', function(newStateObj){
      alert('that.state.mode inside callback: ' + that.state.mode); //alerts commits - as expected
      alert('newStateObj.mode inside callback: ' + newStateObj.mode); //alerts forks - as expected
      that.setState(newStateObj); // Error: setState is not a function
      alert("this.state.forks: " + that.state.forks);
    });
  }