使用JavaScript和Rails制作链接下拉菜单

Question

I am trying to make a drop down menu of links. I use the following in rails to generate the drop down menu:

select("post","id", current_user.admin.post.all.collect {|p| [p.title, post_path(p) ] }, {:include_blank => 'None', :prompt => 'Your Posts'})

As a result of this ruby, the drop down menu looks like this:

<select id="post_id" name="post[id]">
  <option value="">Your posts</option>
  <option value="">None</option>
  <option value="/posts/1">Vacations</option>
</select>

And I am trying to get the following javascript to send the user to the correct url:

$(document).ready(function() {
  $("#post_id").change(function () {
    var newwindow = $("#post_id option:selected").attr("id");
    window.location.replace(newwindow);
  })
});

However, it tries to go to /admins/undefined and comes back with this:

Couldn't find Admin with id=undefined

Any help would be appreciated!

John

Answer 1

You're getting undefined because none of your <option> elements have id attributes, perhaps you want to look at their values:

$("#post_id").change(function () {
  var newwindow = $("#post_id option:selected").attr("value");
  if(newwindow)
      window.location.replace(newwindow);
  else
      // Complain or something.
});

Or just grab the value straight from the <select> :

$("#post_id").change(function () {
  var newwindow = $("#post_id").val();
  if(newwindow)
      window.location.replace(newwindow);
  else
      // Complain or something.
});