FormCollections =============== This plugin effectively rewrites UrlEncodedPairParser and provides the following features/changes: 1. The parameter parsing algorithm is much simpler There's all sorts of wacky stuff happening in the current implementation of UrlEncodedPairParser#parse. This plugin does away with that. A stack is no longer used during the parse. Parsing an Array vs. parsing a Hash is no longer all that different. See lib/patch_url_encoded_pair_parser.rb. 2. Parsing "a[b][0][c]=6" yields {"a" => {"b" => [{"c" => "6"}]}} Previously this would be parsed to: {"a" => {"b" => {"0" => {"c" => "6"}}}} In other words, parameters that were formerly treated as hashes with a numeric index are now actually arrays. This is important, because the order in which form fields are present may be important to the back-end processing code. Here, the array in "b" will preserve the ordering specified -- generating an Array rather than a Hash for numeric indices. Most other scenarios should essentially work as before, with the exception of a few error cases (e.g. parsing "a/b@[c][d[e][]=f" yields {"a/b@" => {"c" => {"d[e" => ["f"]}}} instead of {"a/b@" => {"c" => {}}}). The main problem here is that if an array is instantiated with a value at index 1000000, then we'll have 999999 nil elements. I figure this can easily be worked around with an Array-like structure that consumes only as much memory as it needs but otherwise acts as an Array, or a hard limit set via configuration variable. 3. fields_for now treats Arrays properly ... Example: <% fields_for @post.comments do |comment_form, comment| %> <%= comment.new_record? ? "" : comment_form.hidden_field(:id) %> <%= comment_form.hidden_field :post_id %> <%= comment_form.text_field :content %>

<% end %> This will generate the following HTML for an array with two elements (one a new_record?, the other existing):