Rails - Mar 2006 - What does the send() method do on a model object?

All,

I did a scaffold for a model and I ended up with this code in 
list.rhtml:

 <% for column in TargetList.content_columns %>
    <td><%=h target_list.send(column.name) %></td>
  <% end %>

Where is the "send" method and what does it do?

I can''t find it on ActiveRecord::Base?   I assume that it returns a 
value based on the column id but I can''t find any documentation on it.

Thanks,
Wes

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

Hi --

On Tue, 14 Mar 2006, Wes Gamble wrote:
> All,
>
> I did a scaffold for a model and I ended up with this code in
> list.rhtml:
>
> <% for column in TargetList.content_columns %>
>    <td><%=h target_list.send(column.name) %></td>
>  <% end %>
>
> Where is the "send" method and what does it do?
>
> I can''t find it on ActiveRecord::Base?   I assume that it returns
a
> value based on the column id but I can''t find any documentation on
it.
send sends a message to an object.  In this case, you''re sending the
name of the column to the object in target_list.

Sending a message is basically equivalent to calling a method.  But
since you don''t know the name(s) of the methods in advance
(they''re in
the columns), you use send to generalize the process.

It''s a built-in Ruby facility; it''s used in many programs and
systems,
not just Rails.


David

-- 
David A. Black (dblack@wobblini.net)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

"Ruby for Rails" chapters now available
from Manning Early Access Program! http://www.manning.com/books/black

Send is a method from Object that calls the method you specify. That 
code looks weird to me, but I haven''t played with scaffolding in a 
while.

In normal use, you would probably just call the method directly. In this 
case the method is just the field you want to output.

Wes Gamble wrote:
> All,
> 
> I did a scaffold for a model and I ended up with this code in 
> list.rhtml:
> 
>  <% for column in TargetList.content_columns %>
>     <td><%=h target_list.send(column.name) %></td>
>   <% end %>
> 
> Where is the "send" method and what does it do?
> 
> I can''t find it on ActiveRecord::Base?   I assume that it returns
a
> value based on the column id but I can''t find any documentation on
it.
> 
> Thanks,
> Wes

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

Of course, I didn''t go _all_ the way up the inheritance hierarchy :).

I was kind of hoping it was a mixin so I could learn more about them - 
all in due time, I''m sure.

Thanks,
Wes

Ben Sinclair wrote:
> Send is a method from Object that calls the method you specify. That 
> code looks weird to me, but I haven''t played with scaffolding in a
> while.
> 
> In normal use, you would probably just call the method directly. In this 
> case the method is just the field you want to output.
> 
> Wes Gamble wrote:
>> All,
>> 
>> I did a scaffold for a model and I ended up with this code in 
>> list.rhtml:
>> 
>>  <% for column in TargetList.content_columns %>
>>     <td><%=h target_list.send(column.name) %></td>
>>   <% end %>
>> 
>> Where is the "send" method and what does it do?
>> 
>> I can''t find it on ActiveRecord::Base?   I assume that it
returns a
>> value based on the column id but I can''t find any
documentation on it.
>> 
>> Thanks,
>> Wes

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

Couldn''t you also do something like this ?

<%=h target_list.#{column.name} %>

Untested, but I remember having to call a few methods without knowing their
names first, and used something similar to this... however... send is
probably more aesthetic than any hack I came up with :)


On 3/14/06, Ben Sinclair <ben@bensinclair.com>
wrote:
>
> Send is a method from Object that calls the method you specify. That
> code looks weird to me, but I haven''t played with scaffolding in a
> while.
>
> In normal use, you would probably just call the method directly. In this
> case the method is just the field you want to output.
>
> Wes Gamble wrote:
> > All,
> >
> > I did a scaffold for a model and I ended up with this code in
> > list.rhtml:
> >
> >  <% for column in TargetList.content_columns %>
> >     <td><%=h target_list.send(column.name) %></td>
> >   <% end %>
> >
> > Where is the "send" method and what does it do?
> >
> > I can''t find it on ActiveRecord::Base?   I assume that it
returns a
> > value based on the column id but I can''t find any
documentation on it.
> >
> > Thanks,
> > Wes
>
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
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