I am attempting to use a link_to helper to perform a form post using the following construct:
<%= link_to 'Save', {:action =>'create'}, :post => true %>
What I find is the parameters passed to the webserver are empty. My model validation stuff triggers indicating the fields in question are empty too. This is to create a new DB entry so no ID is being passed, although there are a few required parameters obviously.
This works fine if I use:
<%= submit_tag "Create" %>
View the source of your page. Using link_to with :post => true will turn that link into a mini-form that knows nothing at all about your other form on the site.
If you don't want an actual submit button, then you'll need to use link_to_function and set the function to do document.myform.submit() or some such.
-philip