How to Trigger 'onclick' or 'onchange' on <select>

rubyonrails-talk
1

I have two dropdowns 'a' and 'b'. when something is selected on 'a', its onchange event has an action and an update area which works fine.

but when it comes to editing a record, i am able to list items in 'a' dropdown and select the current value but this leave 'b' dropdown empty.

i would like to trigger an onchange or onclick event for 'a's selected value so that 'b' drop down is populated correctly.

any ideas?

2

This is easily a dhtml issue, or one that can likely be performed in rjs. (repopulating 'b') when someting occurs. Additionally, here is working code I use to pick up when a dropdown's selection has changed:

<% form_for :channels, :html => {:name => 'channelsform'},:url=> { :action =>"newchannel", :controller =>"channels"} do |f| %>     <%= f.label "Channel" %>   <%= select("channel", "id", Channel.find(:all, :order => 'channel ASC', :conditions => ['deleted=0']).collect {|p| [ p.channel, p.id ]}, { :include_blank => true}, { :onchange => "document.channelsform.submit();"}) %>   <input type="hidden" name="minimenu" value="<%= @minimenu %>" /> <%end%>

It;s a little polluted with real-world dictates, but I dont want to hack things out for trhis example and give you a broken example inadvertently. The meat occurs in the :onchange where the form is submitted in this case (when the user changes their selection). Incidentally, this occurs in a partial, which then executes the Channelscontroller.newchannel method. Perhaps you make a partial holding dropdown 'b' and repopulate it in such a method? That should work fine -Janna B

3

Rails List wrote:

I have two dropdowns 'a' and 'b'. when something is selected on 'a', its onchange event has an action and an update area which works fine.

but when it comes to editing a record, i am able to list items in 'a' dropdown and select the current value but this leave 'b' dropdown empty.

i would like to trigger an onchange or onclick event for 'a's selected value so that 'b' drop down is populated correctly.

any ideas?

You can use observe_field which observe 'a' select tag and change the values of 'b'.

Example : select_tag "country", "<option>XYZ</option>"

observe_field 'country',:url => { :controller => 'location', :action => 'location_chooser' },:on => 'click', :with => :q

google more on observe_field and select_tag.