Angular.js ui-sref is not creating hyperlink - angularjs

Question

I know this question might be stupid,but after searching through all over the stackoverflow and other blogs,and video tutorials,I have no other choice left than to ask this on stackoverflow.
I have been learning Angular.js through online tutorials.
I have 2 files.
index.html and app.js
Here is some snaps of my code.
States Configuration Part inside app.js
angular.module('flapperNews', ['ui.router']).config(['$stateProvider','$urlRouterProvider',function($stateProvider, $urlRouterProvider) {$stateProvider
.state('home', {
url: '/home',
templateUrl: '/home.html',
controller: 'MainCtrl'
})
.state('posts', {
url: '/posts/{id}',
templateUrl: '/posts.html',
controller: 'PostsCtrl'
})
$urlRouterProvider.otherwise('home')}]);
Inline templates inside index.html (1-home.html , 2-posts.html)
<ui-view></ui-view>
<script type="text/ng-template" id="/home.html">
<!--home.html part-->
</script>
<script type="text/ng-template" id="/posts.html">
<!--posts.html part-->
</script>
inside home.html I have a hyperlink on Comments.
<div ng-repeat="post in posts | orderBy:'-upvotes'">
<span class="glyphicon glyphicon-thumbs-up"
ng-click="incrementUpvotes(post)"></span>
{{post.upvotes}}
<span style="font-size:20px; margin-left:10px;">
<a ng-show="post.link" href="{{post.link}}">
{{post.title}}
</a>
<span ng-hide="post.link">
{{post.title}}
</span>
<span>
<a ui-sref="/posts/{{$index}}">Comments</a>
</span>
</span>
</div>
Now when I run this WebApp on my localhost it is showing this rendered html of my Comment hyperlink,but it is not providing me any navigation(Hyperlink is not working).
<span>
<a ui-sref="/posts/0">Comments</a>
</span>
Now,I have two questions:
What went wrong with ui-sref part.When I use href instead of ui-sref then it is working perfectly fine.Why is this happening?
I have been using inline templates for home.html and posts.html,but if I make them into separate files then my entire app gets broken.Why?
Any help would be appreciative.

Answer 1

1)The way you have used ui-sref is what is causing it to break.Try this in your application,
<a ui-sref="posts({ id: $index })">Comments</a>
2)Assuming your new template files are as same level as your index.html and app.js you need not mention as templateUrl: '/posts.html',just use templateUrl: 'posts.html'.