Is it possible to use link_to_function to increment value onclick?

rubyonrails-talk
1

Currently, I allow my users to dynamically add new fields to a form using the link_to_function variable. However, whenever a new field is added, its inputs have the same names as the previous fields. I solved this by passing in a local variable, but I can't get that value to increment (or update) on click.

I'm using the following code:

<%= link_to_function "Add Another" do |page|   page.insert_html :bottom, :tasks, :partial => 'stuff', :object => Model.new, :locals => { :num => 1 } end%>

(Yes, that code was take from ryan bates's complex forms series.)

How do I get that :num => 1 to increment every time a user clicks "Add Another." increment and increment! don't seem to work, and I thought about using Time.now.to_i instead of single digit integers (note: it doesn't matter what "num" is as long as it's a number), but that only loads the time when page is first loaded, and doesn't update when "Add Another" is clicked.

So, is there anyway to increment this :num value using client side javascript?

2

There are 2 solutions for this.

1. If you have problem with same name then use array for field name.

2. If you want to update num variable value then you have to update link itself.

I prefer 1st option because of it become easy to get values of unknown fields (because you don't know how many fields are there).

I hope you get my point. or let me know....

3

hmm... I figured it would be easy. then I played with it. It is not easy. I was able to get it working in pure javascript, but could not get it working in rails... maybe someone else can get it, but it seemed to me rails was loading the partial as part of the link AKA the local is set when the link is created.

if you want to see it working in JavaScript it is not too hard. The Main pain is no partial use, you gotta build the partial in the link...

<code>

<script language="javascript"> var count = 0; function getCount() {   return count++; } </script>

<a href="#" onclick="Element.insert(&quot;tasks&quot;, { bottom: &quot;<input type='text' name='random_input_&quot; + getCount() + &quot;'>&quot; }); return false;">Add Another</a>

</code>

I am sure there are a million ways to do it, and some may be better, but I am pretty sure link_to_function will not be in the answer to many if any of them.

Chris CowboyonRails

4

Why do you want to use javascript to increment the field count? This seems like it'd be so much easier to just store the field count in the session and be done with it.

An example for a webmail app I hacked out awhile ago (though I'm still not sure this counting approach in general is the best way to do things:)

Relevant section of main form (Haml):

%fieldset#attachments     %a#add_attachment{ :href => add_attachment_path } Add Attachment

5

I'm using each_with_index, but can't the index value to update each time the user "Adds Another", which is why I was defining a new variable and passing it as well. So I guess that's my real problem, getting each_with_index to update.

6

Your pure javascript way is great!, and a lot cleaner than the link_to_function, which I don't really like anyway. Is there a way to pass in the partial with your javascript method? Like instead of "input type='text' name='random_input_&quot", how can I pass in ":partial => 'stuff', :object => Feed.new" and use getCount() as the :num?

Sorry, I really am noob when it comes to raw Javascript. I've been playing around with it and can't get it to work. I do think this way will be perfect though, so thank you for your help, much appreciated.