Activeadmin and Formtastic: form not responding to :size - ruby-on-rails-3

Question

I am trying to format a form and the text fields respond to some methods, and not others.
I can do things like:
f.input :name, :input_html => { :maxlength => 10 }
f.input :name, :input_html => { :disabled => true }
But if I try to do any of the following, they do not work:
f.input :name, :input_html => { :size => 10 }
f.input :name, :input_html => { :class => 'autogrow' }
f.input :name, :input_html => { :rows => 10, :cols => 10 }
When I try using :size, for instance, the generated html shows that size=10, but is not reflected in the actual form.
These were more or less pulled right from the Formtastic documentation on Github, which the Activeadmin documentation refers to.

Answer 1

I am not sure if your question is solved or not.
However according to Formastic Official WIKI, your code should work:
Customize HTML attributes for any input using the :input_html option.
Typically this is used to disable the input, change the size of a text
field, change the rows in a textarea, or even to add a special class
to an input to attach special behavior like autogrow textareas:
<%= semantic_form_for #post do |f| %>
<%= f.inputs do %>
<%= f.input :title, :input_html => { :size => 10 } %>
<%= f.input :body, :input_html => { :class => 'autogrow', :rows => 10, :cols => 20, :maxlength => 10 } %>
<%= f.input :created_at, :input_html => { :disabled => true } %>
<%= f.input :updated_at, :input_html => { :readonly => true } %>
<% end %>
<%= f.actions %>
<% end %>
https://github.com/justinfrench/formtastic
if your code doesn't work , please check out the error logs, or put more debug info to your erb file, to see if you r rails is running under production mode.

Answer 2

i had the same problem. i wanted a nested form for edit with custom text field size.this worked for me.
form do |f|
f.inputs "Header" do
cf.input :name, :input_html => { :class => 'some_style', :rows => 2, :style => 'width:50%'}
end
f.actions
end
so basically u have to create your own class or just work with the :style.
For nested form u can use this code
form do |f|
f.inputs "Header" do
f.has_many :name,:allow_destroy => true,:new_record => true do |cf|
cf.input :first_name, :input_html => { :class => 'some_style', :rows => 2, :style => 'width:50%'}
end
end
f.actions
end