thr3ads.net - Rails - has_many, find

If this information is useful, please help other people find it:
Share via:

reed

2007-Feb-19 03:17 UTC

has_many, find_all problem

ruby 1.8.5, Rails 1.2.1
Caution - I''m a ruby noob.

I have 2 models - Meeting and Meeting_Items.
As you would expect a meeting has_many :meeting_items and a
meeting_item belongs_to :meeting.

When trying to use find_all to return an array which only includes
"agenda items" I found that it always returned the full array of
meeting_items.
To try to find the fault I have reduced the problem to its'' simplest
form that still gives me the problem.

@meeting.meeting_items.find_all{ |m| false}

The code above still returns the full array of meeting_items for the
meeting, I would expect it to return an empty array.

When I do the following I get an empty array returned, which is what I
expect.
[1,2,3,4,5].find_all{|x| false}

Any help appreciated.

Reed


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Daniel N

2007-Feb-19 03:31 UTC

head link

Re: has_many, find_all problem

On 2/19/07, reed <reedrob-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:>
>
> ruby 1.8.5, Rails 1.2.1
> Caution - I''m a ruby noob.
>
> I have 2 models - Meeting and Meeting_Items.
> As you would expect a meeting has_many :meeting_items and a
> meeting_item belongs_to :meeting.
>
> When trying to use find_all to return an array which only includes
> "agenda items" I found that it always returned the full array of
> meeting_items.
> To try to find the fault I have reduced the problem to its''
simplest
> form that still gives me the problem.
>
> @meeting.meeting_items.find_all{ |m| false}

The find_all is an Array method but meeting_items is not strictly an array
even though it behaves a bit like one.  The find all on a collection of AR
models is a depricated method.   Intead you should use find(:all,
:conditions => ... )




The code above still returns the full array of meeting_items for
the> meeting, I would expect it to return an empty array.
>
> When I do the following I get an empty array returned, which is what I
> expect.
> [1,2,3,4,5].find_all{|x| false}
>
> Any help appreciated.
>
> Reed
I think there are a couple of ways to achive this functionality i think
you''re looking for..

Using
Meeting.find(:all, :conditions => { :field => ''value'' }
)

Or you can set this up in the meeting class as a has_many

class Meeting < AR::B
  has_many :meeting_items
  has_many :agenda_items, :class_name => ''meeting_item'',
:conditions =>
"field=''value''"
end

then call this by
@meeting.agenda_items

I hope this helps.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

reed

2007-Feb-19 03:56 UTC

head link

Re: has_many, find_all problem

Wow, thanks for the info.

has_many :agenda_items, :class_name => ''meeting_item'',
:conditions =>

... is exactly what I am after but I was implementing it in a lame
manner, when compared to this solution.

Cheers,
Reed

On Feb 19, 4:31 pm, "Daniel N"
<has....-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:> On 2/19/07, reed <reed...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
>
>
>
>
> > ruby 1.8.5, Rails 1.2.1
> > Caution - I''m a ruby noob.
>
> > I have 2 models - Meeting and Meeting_Items.
> > As you would expect a meeting has_many :meeting_items and a
> > meeting_item belongs_to :meeting.
>
> > When trying to use find_all to return an array which only includes
> > "agenda items" I found that it always returned the full
array of
> > meeting_items.
> > To try to find the fault I have reduced the problem to its''
simplest
> > form that still gives me the problem.
>
> > @meeting.meeting_items.find_all{ |m| false}
>
> The find_all is an Array method but meeting_items is not strictly an array
> even though it behaves a bit like one.  The find all on a collection of AR
> models is a depricated method.   Intead you should use find(:all,
> :conditions => ... )
>
> The code above still returns the full array of meeting_items for the
>
> > meeting, I would expect it to return an empty array.
>
> > When I do the following I get an empty array returned, which is what I
> > expect.
> > [1,2,3,4,5].find_all{|x| false}
>
> > Any help appreciated.
>
> > Reed
>
> I think there are a couple of ways to achive this functionality i think
> you''re looking for..
>
> Using
> Meeting.find(:all, :conditions => { :field =>
''value'' } )
>
> Or you can set this up in the meeting class as a has_many
>
> class Meeting < AR::B
>   has_many :meeting_items
>   has_many :agenda_items, :class_name =>
''meeting_item'', :conditions =>
> "field=''value''"
> end
>
> then call this by
> @meeting.agenda_items
>
> I hope this helps.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Chris Hall

2007-Feb-19 13:55 UTC

head link

Re: has_many, find_all problem

another thing you might want to look into is using association extensions

has_many :items, :class_name => ''meeting_item'' do
  def agendas
    find(:all, :conditions => ...)
  end

  def some_other_type
    find(:all, :conditions => ...)
  end
end

what''s nice about this is you can now say

# all meeting items
meeting.items

# all agenda meeting items
meeting.items.agendas

# all ''some_other_type'' items
meeting.items.some_other_type



On 2/18/07, reed <reedrob-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:>
> Wow, thanks for the info.
>
> has_many :agenda_items, :class_name => ''meeting_item'',
:conditions =>
>
> ... is exactly what I am after but I was implementing it in a lame
> manner, when compared to this solution.
>
> Cheers,
> Reed
>
> On Feb 19, 4:31 pm, "Daniel N"
<has....-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > On 2/19/07, reed
<reed...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> >
> >
> >
> >
> >
> > > ruby 1.8.5, Rails 1.2.1
> > > Caution - I''m a ruby noob.
> >
> > > I have 2 models - Meeting and Meeting_Items.
> > > As you would expect a meeting has_many :meeting_items and a
> > > meeting_item belongs_to :meeting.
> >
> > > When trying to use find_all to return an array which only
includes
> > > "agenda items" I found that it always returned the full
array of
> > > meeting_items.
> > > To try to find the fault I have reduced the problem to
its'' simplest
> > > form that still gives me the problem.
> >
> > > @meeting.meeting_items.find_all{ |m| false}
> >
> > The find_all is an Array method but meeting_items is not strictly an
array
> > even though it behaves a bit like one.  The find all on a collection
of AR
> > models is a depricated method.   Intead you should use find(:all,
> > :conditions => ... )
> >
> > The code above still returns the full array of meeting_items for the
> >
> > > meeting, I would expect it to return an empty array.
> >
> > > When I do the following I get an empty array returned, which is
what I
> > > expect.
> > > [1,2,3,4,5].find_all{|x| false}
> >
> > > Any help appreciated.
> >
> > > Reed
> >
> > I think there are a couple of ways to achive this functionality i
think
> > you''re looking for..
> >
> > Using
> > Meeting.find(:all, :conditions => { :field =>
''value'' } )
> >
> > Or you can set this up in the meeting class as a has_many
> >
> > class Meeting < AR::B
> >   has_many :meeting_items
> >   has_many :agenda_items, :class_name =>
''meeting_item'', :conditions =>
> > "field=''value''"
> > end
> >
> > then call this by
> > @meeting.agenda_items
> >
> > I hope this helps.
>
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Rails - Feb 2007 - has_many, find_all problem

has_many, find_all problem

Re: has_many, find_all problem

Re: has_many, find_all problem

Re: has_many, find_all problem