rails rjs replacement and swap values

Question

I'm trying to figure out how to use RJS to swap between two fields... i know how to replace the values but I can't seem to figure out how to read it.

Is it not possible to read values thru RJS? Only to replace?

<%= link_to_function "Swap" do |page| 
      #to_value = page[:currency_to].value
      page[:currency_from].value = to_value
      page[:currency_to].value = "test"
     end %>

http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper/JavaScriptGenerator/GeneratorMethods.html#M001664

Answer 1

I don't know much about prototype or rjs, but a quick look at the prototype API shows a getValue(). I would think this has to do with page[:currency_to] returning a prototype element as opposed to just a DOM element.

Maybe try replacing

to_value = page[:currency_to].value

with

to_value = page[:currency_to].getValue()

Can you just use whatever javascript you want in rjs files? My guess is no, since it's Ruby 'rendering' Javascript.

The section of the Rails API you linked to is a bit misleading I think. They don't seem to be referring to an actual 'value', they just use value as the name to be passed to the block.

Answer 2

I tested both of the following.

<%= link_to_function "Swap", 'var tmp_frm = $("#currency_from").val();
                              var tmp_to = $("#currency_to").val();
                              $("#currency_from").val(tmp_to);
                              $("#currency_to").val(tmp_frm);'%>

or better yet

<%= link_to_function "Swap", 'var tmp_frm = $("#currency_from").val();
                              $("#currency_from").val($("#currency_to").val());
                              $("#currency_to").val(tmp_frm);'%>

depending on your html, you may need to remove the pound symbols

<%= link_to_function "Swap", 'var tmp_frm = $("currency_from").value;
                                      var tmp_to = $("currency_to").value;
                                      $("currency_from").value = tmp_to;
                                      $("currency_to").value = tmp_frm;'%>

Answer 3

<%= link_to_function "Swap", 'var tmp_frm = $("currency_from").value;
                                   var tmp_to = $("currency_to").value;
                                   $("currency_from").value = tmp_to;
                                   $("currency_to").value = tmp_frm;'%>