halfgaar
March 15, 2007, 1:36pm
1
Hi,
Is there a way to include associations of the associations you're
including? As
an example, you could have "orders" belonging to an "account", which
in turn
belongs to a "person". When I want to list orders sorted by the name
of the
account owners, I need to be able to do something like:
orders.find(:all, :include => "account.person", :order =>
"person.name")
but that doesn't work... I tried to do it like:
orders.find(:all, :joins => "JOIN accounts AS account
ON account.id = order.account_id
JOIN people AS person
ON person.id = account.person_id",
:from => "order AS order")
But that had the side effect of orders.id becoming the id of person.
So, is there any good way of doing this?
Thanks in advance.
For example:
User.find_by_id(id, :include => [:accounts => [:orders => [:objects]]])
etc.
Hope that helps,
halfgaar
March 15, 2007, 2:04pm
3
OK, I fixed it by doing this:
Order.find(:all, :include => [:account => [:owner]], :order =>
"people.name")
BTW, isn't find_by_id very deprecated?
Deprecated??? Why?
The point is, if you do something like:
@user = User.find(5)
you can crash your app if such a user doesn't exist:
ActiveRecord::RecordNotFound: Couldn't find User with ID=5
But if you write:
@user = User.find_by_id(5)
you'll have a nil object if it doesn't exist. It's so easier to handle:
unless @user
flash[:error] = 'Hey! you don\'t exist!'
end
etc.
My $0.02
RSL
March 15, 2007, 2:26pm
5
But even easier than hitting that shift key twice for find_by_id is
@user = User.find(5) rescue nil
For me, anyhow.
RSL
Héhéhé, AZERTY keyboard rocks!
Anyway, do you put rescue everywhere in your code?
RSL
March 15, 2007, 2:42pm
7
Everywhere? No. But I do use it fairly often when I’m hitting up AR for a record that may or may not exist. Why’d you ask?
RSL
Just for curiosity. I have lots of find_by_something in my app to so
I wanted to know how other developers are managing errors.
RSL
March 15, 2007, 3:10pm
9
My preference for the find rescue nil methodology is just because I learned it first and I hate the shift key. That’s why I type with brackets where properly I should use parentheses.
But seriously rescue is your friend. I’ve got some code that renames thumbnails when the appropriate models attributes change and code like
FileUtils.rm(“#{path}/#{dir}/#{id}.#{extension}”) rescue nil
are a lot easier than checking if the file exists then deleting it. And code like
def attachments_for(entry)
return “(none)” if entry.attachments.empty?
return “(file)” unless entry.has_image
begin
attachment = Attachment.find(entry.has_image)
link_to(image_tag(attachment.image(:square), :alt => “image”), {:action => “edit”, :id =>
entry.id }, :title => “Edit this entry?”)
rescue
“(error! )”
end
end
helps me generate thumbnails on the fly [if they don’t exist] and have a visible representation when something went wrong but not break the app.
RSL
I agree!
To validate date format, I use in my model:
date.propriete = Date.new(value.split('/')[2].to_i,value.split('/')[1].to_i,value.split('/')[0].to_i).strftime '%d/%m/%Y'.to_s rescue date.propriete
If the user type a wrong date in the in_place_editor_field, it won't be
saved.
I just found weird to use the rescue for find method
RSL
March 15, 2007, 3:23pm
11
I thought find rescue nil was normal and the way the tutorials do it. I dunno. Maybe I’m just weird. Well, I know I’m weird.
RSL
I thought find rescue nil was normal and the way the tutorials do it. I
dunno. Maybe I'm just weird. Well, I _know_ I'm weird.
Hey! May be I'm wrong too!
Nobody has provided this method yet:
begin
?> User.find(55)
rescue ActiveRecord::RecordNotFound
nil
ensure
?> puts 'Oops, something goes really wrong'
end
Oops, something goes really wrong
=> nil
(so easy to put it in application.rb)
halfgaar
March 15, 2007, 4:11pm
13
Oh, wait. I was confusing it with find_all... find_by_id is simply
part of the other find_by_<attribute>methods, of course...
I like the idea that find_by_id returns nil and does the same thing as the rescue though. That’s cool.