redirect back in rails

The back button is most commonly used button in web browser.
but it becomes pain to developers very often specially when forms are submitted (in post method)

A back button in web page is useful rather using the browser back button:

here is a simple tip for using back button in web page:

#in appplication_controller.rb (for earlier version application.rb )
before_filter :store_location


private:

def store_location
session[:return_to] = request.env['HTTP_REFERER']
session[:previous_request_method] = request.method #to avoid redirect to post url
end



#in application_helper.rb

def link_to_back_or_default_path(*args)
text = args.first || 'Back'
default_path = args.second || default_path
#default_path can be root_path or any other fixed path
html_options = args.third
if session[:previous_request_method].to_s =='post' || session[:return_to] == ''
redirect_path = default_path
else
redirect_path = session[:return_to]
end
link_to(text, redirect_path, html_options)
end

#in view

<%=link_to_back_or_default_path('back', 'http://boo.com', :class=>'foo, :id=>'bar')%>

or simply
<%=link_to_back_or_default_path%>


Share your thoughts

rails passing parameters in routes generated path

In Rails for a complete, controlled and structured routing we should specify all paths in routes.
sometimes we may need to send some parameters in route

for example we need a route for saved listing for a user.

we can achieve this by the following in routes.rb
map.resources :users, :collection =>{:saved_listing => :get, :other_action =>:post}

the path might be generated by:

Option 1:
saved_listing_users_path(user)//user is an object

Option 2://passing only id
saved_listing_users_path(:id=>user_id)


If we need to add others parameters in url then,

Option 3://passing id with other params
saved_listing_users_path(:id=>user_id, :lan=>'en', :foo =>'bar')


Option 4://passing only hash
param_hash = {:id=>user_id, :lan=>'en', :foo =>'bar'}
saved_listing_users_path(param_hash)

Sometime we may need to pass all parameters to url, then the following will not works:

saved_listing_users_path(params)
because though params is a hash but it includes :controller, :action in key list.

so we need the followings:

param_hash = params.clone //take params clone not params to avoid reference problem
param_hash.delete_if {|key, value| ['controller', 'action'].include?(key) }
//remove controler and action from params
saved_listing_users_path(param_hash)


we can use mix type in parameters like some key,value pair and a hash.
then we have to use :params key for the hash in parameter list
saved_listing_users_path(:id=>34, :params=>param_hash)


I think this will be helpfull a little.
and you all are welcome to share your thoughts

Date difference in rails

when we are working on rails, sometimes we may require this

Say, we have User model and we need to find out how many days he registered.
You can have lots of ways to find that as you are on Rails(some might have some problem though)

here is another way(I think it will work smartly )

user = User.find(#id)

"Registered #{user.created_at.to_date - Date.today).to_i} days ago"

Similarly for days difference between two days :

(user1.created_at.to_date - user2.created_at.to_date).to_i

Cheers!