Make a Select Box that Calls a Method - ruby-on-rails

Question

I have a rails app with working reports that have tags. In the Report/Index.html.erb I want the user to be able to sort the reports by selecting a tag. They may only select one tag at a time so I feel that a select box would work best. I currently have this:
<%= select("preferences", :tag_with,
["Politics", "Technology", "Entertainment", "Sports", "Science", "Crime",
"Business", "Social", "Nature", "Other"], :prompt => "Filter Feed by:" )%>
I have a working preferences controller with a method call tag_with that updates the current tag. This code, however, only generates the select box. I want it to be that when the user selects one of the tags, it calls the tag_with method from the preferences controller.
I generated a series of link_to lines that complete the task, however I would really like a select box.
<%= link_to "Politics", :action => "tag_with", :tag => "Politics", :controller =>"preferences" %>
<%= link_to "Entertainment", :action => "tag_with", :tag => "Entertainment", :controller =>"preferences" %>
<%= link_to "Science", :action => "tag_with", :tag => "Science", :controller =>"preferences" %>
<%= link_to "Technology", :action => "tag_with", :tag => "Technology", :controller =>"preferences" %>
And so on for each tag. This works fine but is bulky and undesirable. Is there a way to do the same thing through a select box?

Answer 1

In your reports.js.coffee file, or whatever other js file you want.
jQuery ->
$('select#preferences').change ->
$.get 'preferences/tag_with',{ term: $('option:selected', this). val() }
Or, if you want to use regular javascript:
$(function(){
$('select#preferences').change( function() {
$.get('preferences/tag_with',{term: $('option:selected',this).val()});
});
});
A link is a GET request. The jQuery .change() method fires whenever someone makes a change. The $.get method sends a GET request to a URL and can pass data (the second argument). This data becomes your params hash, so in the example above you would get:
params[:term] #=> the value attribute of whatever option was selected by the user
See the jQuery docs on .change() and $.get() for more help.
Update
For this to refresh the page, the easiest thing would be to extract the table that you want changed into a partial, let's assume it's called _report.html.erb. The partial should look something like this:
<div id="report">
<%= render #report %>
</div>
*Note: render #report is just short for render :partial => 'report'. See http://guides.rubyonrails.org/layouts_and_rendering.html*
In your preferences controller, tag_with option you should be sure to set the #report object (or whatever else is delivering the data to your partial).
Then you should make a file called views/preferences/tag_with.js.erb and put something like this in it:
$('div#report').html('<%= escape_javascript( render #report ) %>');
This will update the report container with the new content.