Cool, glad to help.
You want Enumerable#select (aka #grep) to return an array of all the
matching results.
Making the most out of Ruby's built-in (or ActiveSupport-extended)
Enumerable functionality is a common area for improvement people see,
so I think there are some good guides out there - google should sort
you out.
Cheers,
Will
On Tue, Aug 4, 2009 at 10:25 PM, Stijnster<st...@skylight.be> wrote:
>
> Hi Will,
>
> indeed, I am looking for a way to search in already loaded sets,
> instead of caching the query itself. When running an import job, I
> want to prevent a hit on the database for each color lookup when I'm
> importing +1000 of records.
>
> Detect sounds great! It would indeed help me to identify all records.
> So I think I'll go with that. Thanks for pointing me into that
> direction.
>
> One thing detect doesn't do (for as far as I can see/test) is return a
> set that matches the detected data (e.g. when "blue" is found several
> times, using a regexp, it would only return the first instance where
> blue is detected). In my example above you can
> specify :all, :one, :first, ... which return the appropriate result.
>
> But again, thanks for your advice!
>
>
> Stijn
>
>
>
>
>
> On Aug 4, 12:12 pm, Will Bryant <will.bry...@gmail.com> wrote:
>> Ryan, he is talking about a mechanism for use with already-loaded
>> arrays or collections, so reducing the number of queries made, as is
>> clear from his examples.
>>
>> Regarding your next email, there is no mechanism to preload several
>> named_scopes on the same model with different conditions in one query,
>> nor would it be at all easy to do in SQL, and reducing the number of
>> separate queries needed is what Stinjster's interested in.
>>
>> Stinjster, I'm not aware of a mechanism to do this. I think it would
>> sometimes be useful, but it's probably not going to get used by too
>> many people as most of the time people just need to load a certain set
>> of records, and then index them by a particular thing. For example,
>> it's quite common to use:
>>
>> @colors_by_name = Color.all.index_by(&:name)
>> @item.color = @colors[color_for_import]
>>
>> What you're talking about is really a more generalised mechanism for
>> doing Enumerable#detect calls, but I think they're already short
>> enough to write for the bulk of use cases, so I would say that most
>> people would be happy to use:
>>
>> @item.color = @colors.detect {|color| color.name =~ /test}
>>
>> which isn't really any more verbose than:
>>
>> @item.color = @colors.search(:all, :conditions => {:name => /test/})
>>
>> (And is more powerful since you can put in arbitrary ruby code.)
>>
>> Could you give an example where a #search method is really a time
>> saver over #detect?
>>
>> On Tue, Aug 4, 2009 at 10:02 PM, Ryan Bigg
>>
>> (Radar)<radarliste...@gmail.com> wrote:
>> > Uh yeah, Color.all(:conditions => { :name => color_from_import })
>>
>> >http://guides.rubyonrails.org/active_record_querying.html
>> > 2009/8/4 Stijnster <st...@skylight.be>
>>
>> >> Here's an idea,
>>
>> >> I'm making an import module for a customer and have to look up related
>> >> models all the time to link them to the imported record;
>>
>> >> ...
>> >> @item.color = Color.find_by_name(color_from_import)
>> >> ...
>>
>> >> Instead of hitting the database all the time, I'm extending the array
>> >> class with a "search" call that searches values in a preloaded list
>> >> "ActiveRecord find" style;
>>
>> >> @colors = Color.all
>> >> ...
>> >> @item.color = @colors.search(:first, :conditions => { :name =>
>> >> color_from_import })
>>
>> >> or
>>
>> >> @item.color = @colors.search(12)
>> >> @item.color = @colors.search(:all, :conditions => { :name => /test/})
>>
>> >> Can someone tell me if behaviour like this is already implementent (in
>> >> core or using a plugin)? Here is my (premature) plugin code;
>>
>> >>http://pastie.org/570795
>>
>> >> Stijn
>>
>> > --
>> > Ryan Bigg
> >
>
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