# Memcache for variables

**URL:** <https://www.ruby-forum.com/t/memcache-for-variables/168835>\
**Category:** Rails\
**Created:** [May 26, 2009, 3:26pm UTC](https://www.ruby-forum.com/t/memcache-for-variables/168835 "2009-05-26T15:26:49Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![wakathane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ecae2f/32.png) [@wakathane](https://www.ruby-forum.com/u/wakathane)\
**Post date:** [May 26, 2009, 3:26pm UTC](https://www.ruby-forum.com/t/memcache-for-variables/168835/1 "2009-05-26T15:26:49Z")

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hey,

for performance reasons i want to cache (template) variables using  
memcache, making access to data easy in templates by using a simple  
syntax like \<%=users(2).name%\>. this actually should tell the view to  
load the field ‘name’ from the model/table ‘users’ with id=2. it first  
tries memcache and if not found, loads the data from the and stores it  
in memcache.

has anyone done this before, any ready to use plugins available? :).  
if not, any ideas/suggestions on how to implement this best in ror?

caching partials or whole actions is not an option because of too  
complex dependencies.

thanks

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**Author:** ![wakathane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ecae2f/32.png) [@wakathane](https://www.ruby-forum.com/u/wakathane)\
**Post date:** [May 26, 2009, 8:34pm UTC](https://www.ruby-forum.com/t/memcache-for-variables/168835/2 "2009-05-26T20:34:00Z")

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in your config/environment/development.rb file (or whatever  
environement your are configuring)

config.cache\_store = :mem\_cache\_store

Depending on how much memory you want to consume you can either load  
your whole user model, the name to ID collection or just the users  
that log in.

In the User model do something like:

def self.names  
Rails.cache.fetch(‘user\_names’, :expires\_in =\> 3600)  
{User.all.collect {|u| [u.id,u.name]}} # names are cached for 1hr  
(3600 seconds)  
end

again in your controller:

def list  
@names ||= User.names.sort  
end

in your view:  
\<% @names.each do |name| -%\>  
\<%= name[0] -%\>  
  
\<% end -%\>

If the names aren’t cached or the cache is older than the one hour  
defined in the model then the fetch method knows to go grab them  
afresh.

I’m using memcache in a more complex manner with full objects and it  
works like a charm - as a matter of fact this has taken common  
requests for fetching data completely off of the database. I rebuild  
the cache without using expiration by implementing callbacks on  
modification of the underlying data - this has taken load times for  
data intensive / cmplex data sets from 20+ seconds down to an  
imperceivable delay… makes clients happy to see that kind of  
improvement. 🙂

Naturally you will need to have the memcache service running somewhere  
in your environment.  
Hope that helps  
Ben

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**Author:** ![wakathane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/ecae2f/32.png) [@wakathane](https://www.ruby-forum.com/u/wakathane)\
**Post date:** [May 26, 2009, 8:35pm UTC](https://www.ruby-forum.com/t/memcache-for-variables/168835/3 "2009-05-26T20:35:46Z")

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Except in the collection you actually would put [u.name,u.id]