# Acts\_as\_queue

**URL:** <https://www.ruby-forum.com/t/acts-as-queue/95389>\
**Category:** Rails\
**Created:** [May 31, 2006, 12:24am UTC](https://www.ruby-forum.com/t/acts-as-queue/95389 "2006-05-31T00:24:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![carmen](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/a9adbd/32.png) [@carmen](https://www.ruby-forum.com/u/carmen)\
**Post date:** [May 31, 2006, 12:24am UTC](https://www.ruby-forum.com/t/acts-as-queue/95389/1 "2006-05-31T00:24:22Z")

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wondering if anyone tried this patch. (i havent, seeing as its 1228  
lines long, 10 months old, and cant take serious a patch many orders  
larger than competing web frameworks)

in many cases i want to keep about 10 things around, eg recent searches,  
new items (spanning multiple classes), referers, page views, without  
logging them for perpetuity. so i guess this isnt a normal queue, more  
like a pipe with a burning substance at one end…

my initial thoughts are 1) disable id auto-incremenet, find the oldest  
record out of 10, and overwrite that with the newest (doing this via  
normal model callbacks). or 2) use acts\_as\_list, and reorder all the  
records whenever one is added (acts\_as\_nested\_set seems to do this, but  
it seems like a bit of a kludge). any other obvious and simple  
solutions?

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<div class="post-metadata">

**Author:** ![carmen](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/a9adbd/32.png) [@carmen](https://www.ruby-forum.com/u/carmen)\
**Post date:** [May 31, 2006, 5:26am UTC](https://www.ruby-forum.com/t/acts-as-queue/95389/2 "2006-05-31T05:26:16Z")

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How about storing an array in session and keeping it trimmed?

–  
– Tom M.

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<div class="post-metadata">

**Author:** ![carmen](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/a9adbd/32.png) [@carmen](https://www.ruby-forum.com/u/carmen)\
**Post date:** [May 31, 2006, 7:45am UTC](https://www.ruby-forum.com/t/acts-as-queue/95389/3 "2006-05-31T07:45:48Z")

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> my initial thoughts are 1) disable id auto-incremenet, find the oldest  
> record out of 10, and overwrite that with the newest (doing this via  
> normal model callbacks). or 2) use acts\_as\_list, and reorder all the  
> records whenever one is added (acts\_as\_nested\_set seems to do this,  
> but  
> it seems like a bit of a kludge). any other obvious and simple  
> solutions?

Is this per-user? It seems like it’d be nice to say:

some\_user.recent\_searches.create\_in\_queue(:query =\> “Mishaps”)

I actually don’t know how to disable auto-incrementing off the top of  
my head, and isn’t that database-dependent? Maybe you could say:

create\_table :recent\_searches, :id =\> false do |t|  
t.column :user\_id, :integer  
t.column :position, :integer  
t.column :query, :string  
end

And then have a has\_many :recent\_searches with an extension on that  
which deletes extras, puts the new recent\_search before everything,  
and then increments everything’s position by 1:

class User \< ActiveRecord::Base

```
 has_many :recent_searches, :order => 'position asc' do
   def create_in_queue(options, limit = 10)
     @reflection.klass.delete_all("position >= #{limit} and (#

```

{@finder\_sql})") if self.count \> limit - 1  
search = create(options.update({:position =\> 0}))  
@reflection.klass.update\_all(“position = (position + 1)”,  
@finder\_sql)  
self.reload  
search  
end  
end

end

This reaches into the association’s internals a bit. Maybe there is a  
better way?

And if it’s not per-user, the same sort of thing (without that  
user\_id field):

class PageView \< ActiveRecord::Base

```
 def self.create_in_queue(options, limit = 10)
   self.delete_all("position >= #{limit}") if self.count > limit - 1
   view = self.create(options.update({:position => 0}))
   self.update_all("position = (position + 1)")
   view
 end

```

end

You can say PageView.create\_in\_queue(), but stuff like PageView.first  
and PageView.each would also be nice…

I have tests for these if you want. (Using sqlite3.) I guess these  
could be made into a plugin.

–  
Michael D.  
[http://www.mdaines.com](http://www.mdaines.com)