Express.get is getting variable name instead of it's value from AngularJS ui-router
<p>As I mention in my title, when I send a param to the url using ui-router, and try to use express.get(url), I get the :param name instead of it's value.</p>

<p>Here is my code:</p>

<p>AngularJS ui-router state:</p>

<pre><code>.state('post', {
    url: '/blog/:postID',
    templateUrl: 'app/views/post.html',
    controller: 'PostCtrl'
})
</code></pre>

<p>AngularJS http request</p>

<pre><code>$http.get('/blog/:postID').success(function(data) {
    console.log(data);
    $scope.singlePost = data;
}).catch(function(error) {
    console.log(err);
});
</code></pre>

<p>HTML ui-router url</p>

<pre><code>&lt;h1&gt;&lt;a ui-sref="post({ postID: post._id })"&gt;{{ post.title }}&lt;/a&gt;&lt;/h1&gt;
</code></pre>

<p>express.get() method</p>

<pre><code>app.get('/blog/:id', function(req, res) {
    Post.findById(req.params.id, function(err, singlePost){
        console.log(singlePost);    
        if (err) {
            console.log(err);
        } else {
            res.json(singlePost);
        }
    });
});
</code></pre>

<p>I get the following error in the console</p>

<pre><code>{ [CastError: Cast to ObjectId failed for value ":postID" at path "_id"]
  message: 'Cast to ObjectId failed for value ":postID" at path "_id"',
  name: 'CastError',
  kind: 'ObjectId',
  value: ':postID',
  path: '_id',
  reason: undefined }
</code></pre>

<p>Any help and/or explanation of why it's happening for a newbie would be appreciated.
Thank you.</p>