Ferret talk - Dec 2007 - please explain find_with_ferret, retrieve_records, :include and :conditions

Hello, I''m using find_with_ferret to search multiple models and it  
works great. The trouble is I need to filter the results  
using :include and :conditions.

I get two errors depending on the syntax I use in the search. Reading  
the source, I see the retrieve_records method seems to filter  
the :include and :conditions so that they only apply to the relevant  
model when searching multiple models. This is exactly what I want, but  
I can''t seem to get it to work.

My question: is my syntax wrong? Or have I misread how retrieve_record  
works? If so, How would I apply conditions to a subset of models being  
searched in a multi model search?

# First Try. This syntax with using a hash to contain the include  
params works with regular active_record calls.
       @results = Inventory.find_with_ferret( @query,
					     { :multi => [ Artist], :page => params[ :page ], :per_page  
=> 10 },
					     { :include => {:media_files => {}}, :conditions =>  
[ "media_files.file and inventories.status =
''donated''" ] } )
	


# Resulting Error
undefined method `to_sym'' for [:media_files, {}]:Array


# Second try. I put the :include params in [] array brackets to see if  
that would help the to_sym error. That fixes the to_sym error. But now  
the association isn''t getting found?
       @results = Inventory.find_with_ferret( @query,
                                            { :multi =>  
[ Artist], :page => params[ :page ], :per_page => 10 },
                                            { :include =>  
[:media_files => {}], :conditions => [ "media_files.file and  
inventories.status = ''donated''" ] } )

# Resulting Error
Association named ''media_files'' was not found; perhaps you
misspelled
it?


Thanks in advance.

J-C

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Hi,

first of all, the include options should be a simple Array of Symbols,
or, if you only want to include one relationship, a single Symbol,
like

:include => [ :media_files ]
or
:include => :media_files

And yes, aaf will filter these includes for each model.

Second, aaf unfortunately does not support specifying conditions on a
per model basis yet, so the sql resulting from your conditions argument
has to be valid for fetching records from each of the models you query -
in short, only use attributes present in all of the models.

Afair there''s already a trac ticket regarding the implementation of
per-model conditions for multi search, but I didn''t find the time to
implement this yet. I''ll try to have a look into this over the weekend.


Cheers,
Jens

On Thu, Dec 13, 2007 at 03:28:09PM -0500, Jean-Charles Carelli
wrote:
> Hello, I''m using find_with_ferret to search multiple models and it
> works great. The trouble is I need to filter the results  
> using :include and :conditions.
> 
> I get two errors depending on the syntax I use in the search. Reading  
> the source, I see the retrieve_records method seems to filter  
> the :include and :conditions so that they only apply to the relevant  
> model when searching multiple models. This is exactly what I want, but  
> I can''t seem to get it to work.
> 
> My question: is my syntax wrong? Or have I misread how retrieve_record  
> works? If so, How would I apply conditions to a subset of models being  
> searched in a multi model search?
> 
> # First Try. This syntax with using a hash to contain the include  
> params works with regular active_record calls.
>       @results = Inventory.find_with_ferret( @query,
> 					     { :multi => [ Artist], :page => 
> 					     params[ :page ], :per_page  => 10 },
> 					     { :include => {:media_files => 
> 					     {}}, :conditions =>  [ "media_files.file and
inventories.status =
> ''donated''" ] } )
> 	
> 
> 
> # Resulting Error
> undefined method `to_sym'' for [:media_files, {}]:Array
> 
> 
> # Second try. I put the :include params in [] array brackets to see if  
> that would help the to_sym error. That fixes the to_sym error. But now  
> the association isn''t getting found?
>       @results = Inventory.find_with_ferret( @query,
>                                            { :multi =>  
> [ Artist], :page => params[ :page ], :per_page => 10 },
>                                            { :include =>  
> [:media_files => {}], :conditions => [ "media_files.file and  
> inventories.status = ''donated''" ] } )
> 
> # Resulting Error
> Association named ''media_files'' was not found; perhaps
you misspelled
> it?
> 
> 
> Thanks in advance.
> 
> J-C
> 
> _______________________________________________
> Ferret-talk mailing list
> Ferret-talk at rubyforge.org
> http://rubyforge.org/mailman/listinfo/ferret-talk
-- 
Jens Kr?mer
http://www.jkraemer.net/ - Blog
http://www.omdb.org/     - The new free film database

Jens Kr?mer wrote:
> Afair there''s already a trac ticket regarding the implementation
of
> per-model conditions for multi search, but I didn''t find the time
to
> implement this yet. I''ll try to have a look into this over the
weekend.
Hey Jens, did you actually manage to get to this over the weekend? I was 
looking over the code in your RDOC for AAF, and I saw the following in 
class_methods.rb, line 377:

        # check for per-model conditions and take these if provided
        if conditions = find_options[:conditions]
          key = model.underscore.to_sym
          conditions = conditions[key] if Hash === conditions
        end

And then I noticed my copy of the code (from stable release) didn''t
have
those lines. So I update to the bleeding edge of trunk, and it sure 
looks like per-model conditions are in place and working (at least with 
my set of models they appear to be working).

So, are per-model conditions working as you would expect them to be 
working? Or am I completely out to lunch and imagining things?

- Sheldon Maloff
-- 
Posted via http://www.ruby-forum.com/.

Hi!

Yeah, I experimented with this and it should work as intended. However
I''m not sure I like it the way it is now - imho it would be cleaner to
have not only conditions on a per model basis, but other AR options like
include or group_by, too.

That''s why I didn''t announce this feature yet, I just wanted
to think
about it a bit more ;-)

One way to specify these per-model options might with in the :multi
option:

find_with_ferret query, :multi => {
                          :model_a => { :conditions =>
[''a=?'', a_Value ] },
                          :model_b => { :include => :some_relationship }
                        }

What do you think?

Cheers,
Jens

On Tue, Dec 18, 2007 at 07:35:25AM +0100, Sheldon Maloff
wrote:
> Jens Kr?mer wrote:
> 
> > Afair there''s already a trac ticket regarding the
implementation of
> > per-model conditions for multi search, but I didn''t find the
time to
> > implement this yet. I''ll try to have a look into this over
the weekend.
> 
> Hey Jens, did you actually manage to get to this over the weekend? I was 
> looking over the code in your RDOC for AAF, and I saw the following in 
> class_methods.rb, line 377:
> 
>         # check for per-model conditions and take these if provided
>         if conditions = find_options[:conditions]
>           key = model.underscore.to_sym
>           conditions = conditions[key] if Hash === conditions
>         end
> 
> And then I noticed my copy of the code (from stable release)
didn''t have
> those lines. So I update to the bleeding edge of trunk, and it sure 
> looks like per-model conditions are in place and working (at least with 
> my set of models they appear to be working).
> 
> So, are per-model conditions working as you would expect them to be 
> working? Or am I completely out to lunch and imagining things?
> 
> - Sheldon Maloff
> -- 
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Ferret-talk mailing list
> Ferret-talk at rubyforge.org
> http://rubyforge.org/mailman/listinfo/ferret-talk
-- 
Jens Kr?mer
webit! Gesellschaft f?r neue Medien mbH
Schnorrstra?e 76 | 01069 Dresden
Telefon +49 351 46766-0 | Telefax +49 351 46766-66
kraemer at webit.de | www.webit.de
 
Amtsgericht Dresden | HRB 15422
GF Sven Haubold

I thought that the current implementation looked like a quick-fix! That 
said, it solved an immediate problem, so I''ll continue to use it until 
what you proposed below comes along.

I like what I see below. My question would be, if I had three models, 
ModelA, ModelB, and ModelC and all three had conditions and includes, 
how would the statement look? Would it be:

ModelA.find_with_ferret(query, {
    :page => 1, :per_page => 5,
    :multi => {
         :ModelB => { :conditions => [''b=?'', b_Value ],
:include =>
:some_B_relationship] },
         :ModelC => { :conditions => [''c=?'', c_Value ],
:include =>
:some_C_relationship] },
    }
  },
  { :conditions => [''a=?'', a_Value ], :include =>
:some_A_relationship]
} )

or would it be:

ModelA.find_with_ferret(query, {
    :page => 1, :per_page => 5,
    :multi => {
         :ModelA => { :conditions => [''a=?'', a_Value ],
:include =>
:some_A_relationship] },
         :ModelB => { :conditions => [''b=?'', b_Value ],
:include =>
:some_B_relationship] },
         :ModelC => { :conditions => [''c=?'', c_Value ],
:include =>
:some_C_relationship] }
    }
  } )

In the first example, the conditions for ModelA are left hanging in the 
find_options argument, as they would be with a single model search. The 
second example is much cleaner, and is (I think) what happens internally 
with the method call add_self_to_model_list_if_necessary(). The problem 
with the second example, is that the syntax between a single model 
search and multi-model search would be different.

Looking over the AAF code, perhaps it doesn''t really matter. People 
could use whatever syntax they''re comfortable with.

The last question to ponder would be, what if I didn''t have any 
conditions or includes? Would it be

ModelA.find_with_ferret(query, {
    :page => 1, :per_page => 5,
    :multi => {
         :ModelB => {  },
         :ModelC => {  }
    }
  } )

I don''t think I helped any, did I? What I can say, is I like bringing 
the conditions into the :multi, rather than having to specify the :multi 
as an array and then the conditions as a hash, but I can see the 
inconsistencies it brings to the table.

Cheers,
- Sheldon Maloff

Jens Kraemer wrote:
> find_with_ferret query, :multi => {
>                           :model_a => { :conditions =>
[''a=?'', a_Value ]
> },
>                           :model_b => { :include =>
:some_relationship }
>                         }
> 
> What do you think?
-- 
Posted via http://www.ruby-forum.com/.