Deprecation

Action Pack

components: use partials and helper methods instead
@params, @session, @flash, @request, @cookies, @headers, @response: Use the params, session, flash, etc methods instead of working with the instance variables directly.
url_for(:symbol, *args), redirect_to(:symbol, *args): use named routes instead
render_text, render_template, etc.: Use e.g. render :text => ..., render :template => ..., etc.
redirect_to_path, redirect_to_url.: Use redirect_to.
post_format, formatted_post?, xml_post?, yaml_post?: Use respond_to or request.format.
start_form_tag and end_form_tag: Use form_tag with a block.
update_element_function: use RJS
link_to_image, link_image_to helper methods: use link_to(image_tag(..), url)
human_size helper alias: use number_to_human_size helper method

find_first, find_all: Use find :first and find :all.
push_with_attributes: Use has_many :through for rich many-to-many associations.
*association*_count: Use *association*.count instead