index.html

<template name="basic_typehead">
  <form class="add-course">
    <div>
      <div class="form-group">
        <input class="form-control typeahead" name="courses" type="text"
                 placeholder="Add a course" autocomplete="off" spellcheck="off"
                data-source="getCourses"/>
        <input type="submit" id="hide"/>
      </div>
    </div>
  </form>
</template>

index.js

Template.basic_typehead.events({
  // I also tried with 'submit form'
  'submit form': function (event) {
      event.preventDefault();
      console.log("submit called");
      var text = event.target.text.value;

      // insert the task into the database
      Meteor.call("addCourseToUser", text);

      // clear form
      event.target.text.value = "";

      // Prevent default form submit
      return false;
    }
});