How to make a newly posted comment the selector in jquery (with rails)?

I am trying to highlight the new message @micropost when it is posted using the second line of this code but am not having any success:

$("table.microposts").prepend("<%= escape_javascript(render(:partial => 'shared/feed_item', :object => @micropost)) %>"); 

$("#table.micropost_<%= @micropost.id %>").effect("highlight", {}, 3000);

$("#new_micropost")[0].reset();

This is the feed item partial (I tried using the div_for function to identify the new post...:

<tr> <%= div_for fee开发者_如何学编程d_item do %> 
    <td class="gravatar">
        <%= link_to gravatar_for(feed_item.user), feed_item.user %> 
    </td>
    <td class="micropost"> 
        <span class="user">
            <%= link_to feed_item.user.name, feed_item.user %> 
        </span>
        <span class="content">
            <%= feed_item.content %>
        </span>
        <span class="timestamp">
            Posted <%= time_ago_in_words(feed_item.created_at) %> ago. 
        </span>
    </td>
    <% if current_user?(feed_item.user)%>
        <td>
            <%= link_to "delete", feed_item, :method => :delete,
                                             :confirm => "You sure?",
                                             :title => feed_item.content %>
        </td>
    <% end %>   
<% end %>

</tr>

<% if @feed_items.any? %>
    <table class="microposts" summary="Status feed">
        <%= render :partial => 'shared/feed_item', :collection => @feed_items %> 
    </table>
    <%= will_paginate @feed_items %>
<% end %>

Hope that gives sufficient detail. Thanks for any help

You can use prependTo instead of prepend and then do it like:

$("<%= escape_javascript(render(:partial => 'shared/feed_item', :object => @micropost)) %>").
    prependTo($("table.microposts")).
    effect("highlight", {}, 3000);

You will need the .live() function, if you add something after the page was loaded (i.e with prepend).

Have a look here: http://api.jquery.com/live/