AngularJS ng点击未启动

我的应用程序中有一个ng点击，当点击元素时它不会启动。

HTML:

<div class="col-md-7" ng-controller="githubController">
  <div class="panel commitPanel">
    <table class="table">
      <thead>
        <th>sha</th>
        <th>Author</th>
        <th>Message</th>
        <th>Date</th>
      </thead>
      <tbody></tbody>
    </table>
  </div>
</div>

app.js:

.controller("githubController",["$scope", function($scope){
    $.ajax({
      type: "GET",
      url: "https://api.github.com/users/jmona789/repos?sort=pushed",
      success: function(repos) {
        for(var i = 0; i < repos.length; i++) {
          var newListItem = buildListGroup(repos[i]);
          $(".list-group").append(newListItem);
        }
      },
      error: function(jqXHR, textStatus, errorThrown) {
        alert("Something went wrong. We are looking into it!");
      }
    });
    function buildListGroup(repoData) {
      var commitsApiUrl = "https://api.github.com/repos/";
      commitsApiUrl += repoData.owner.login + "/";
      commitsApiUrl += repoData.name + "/commits";
      var newLink = $("<a>")
        .attr("url", commitsApiUrl)
        .attr("ng-click", 'buildCommits()')
        .addClass("list-group-item")
        .append(repoData.full_name);
      return newLink;
    }

所有这些都很好，它为每个元素添加了ng点击^

但当我点击每个元素时，控制器中的这个功能永远不会启动：

    $scope.buildCommits = function(){
      $.ajax({
        type: "GET",
        url: $(this).attr("url"),
        success: function(commits) {
          $("tbody").empty();
          for(var i = 0; i < commits.length; i++) {
            $("tbody").append(buildTableRow(commits[i]));
          }
        }
      })
      function buildTableRow(commitData) {
        var commitUrl = commitData.html_url;
        var shaTd = $("<td>").append($("<a href="+commitUrl+">").html(commitData.sha).attr("target", "_blank"));
        var authorTd = $("<td>").append(commitData.author.login);
        var messageTd = $("<td>").append(commitData.commit.message);
        var dateTd = $("<td>").append(commitData.commit.author.date);

        return $("<tr>").append(shaTd)
          .append(authorTd)
          .append(messageTd)
          .append(dateTd);
      }
    }
  }])