RAILS / HTML：每7秒钟更改一次图片幻灯片

Question

I've seen a lot of questions like mine here in stack just like these three: 1 , 2 and 3 . But I tried their way but it didn't work.

I am looking for a more simple way. Using Javascript in-line in html, I tried to have this code (which I found in one of those questions here in stack)

<script>
function FetchData() {
  $("#pack").animate({
      left: '-1000px'
  }, 'slow');
}
setTimeout(FetchData, 7000); </script>

and have this as well...

<img id="pack" src="image.jpg">

but it seems to not work. Nothing happened. I have looked and stared at the photo for over a minute and it did not move at all. What was wrong? Do I lack some codes? I have no css code that relates to this by the way.

Answer 1

When your teacher says "separate js and html", and that you shouldn't use inline javascript, they probably mean that you should have something like this setup:

in your layout, include a javascript file (this might be included by default). It's best to put these down the bottom. If there's a default layout it might have a place for javascript includes already.

<%= javascript_include_tag "application" %>

in your view

<img id="pack" src="image.jpg">

in application.js

$(function() {
  //run on dom ready
  console.log("about to setTimeout");
  setTimeout(FetchData, 7000);
  console.log("done setTimeout");
});

function FetchData() {
  console.log("in FetchData, about to animate, $('#pack').size() = "+$('#pack').size());
  $("#pack").animate({
      left: '-1000px'
  }, 'slow');
}

Answer 2

Try to use carousel using bootstrap and put this on the topmost part of your code:

<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>

This is the code for the slides in html:

            <div class="carousel slide" id="myCarousel" data-ride="carousel">
                <ol class="carousel-indicators">
                    <li class="active" data-slide-to="0" data-target="#myCarousel">
                    </li>
                    <li data-slide-to="1" data-target="#myCarousel">
                    </li>
                    <li data-slide-to="2" data-target="#myCarousel">
                    </li>
                </ol>
                <div class="carousel-inner">
                    <div class="item active">
                        <%= image_tag 'image_1.jpg' %>
                    </div>
                    <div class="item">
                        <%= image_tag 'image_2.jpg' %>
                    </div>
                    <div class="item">
                        <%= image_tag 'image_3.jpg' %>
                    </div>
                </div>
                <a class="left carousel-control" href="#myCarousel" data-slide="prev">
                    <span class="glyphicon glyphicon-chevron-left"></span>
                </a>
                <a class="right carousel-control" href="#myCarousel" data-slide="next">
                    <span class="glyphicon glyphicon-chevron-right"></span>
                </a>
            </div>

and this is the javascript in-line code:

<script type="text/javascript">
    $(document).ready(function(){
        $("#myCarousel").carousel({
            interval : 7000,
            pause: false
        });
    });
</script>