Rails - Jul 2006 - checkboxes with a has_many :through relation

All,

I''m populating a view with checkboxes in a list.  I want to be able to 
assign to my has_many relationship using the post values of these 
checkboxes.  Essentially, I want to populate the relationship table 
which will create the correct join values in my model.

Here is my check_box_tag code:

<%= check_box_tag("@current_job[target_list_ids][]",
                   tlist.DataSetID,
                   @current_job.target_lists.include?(tlist)) %>

So, in this example, tlist is an element of another array that I''m 
starting with to give me the list of choices.  But what I want is to 
assign these choices into the "target_lists" collection of my 
@current_job object (again, via the "through" table based on my
has_many
definition.

current_job :has_many target_lists :through an association.

I first followed the examples of using checkboxes with HABTM.  However, 
since I switched my model to user has_many :through, and so I''m pretty 
sure that I no longer get the target_lists_ids method above like I would 
if I were using HABTM.

And actually, I''m not sure I care about that, since I know I should
just
be able to process through the values that I get from the form anyway. 
I''m having trouble getting at the values of the checkbox, even though
in
my parameter list, I see that they are available:

"@current_job"=>{"target_list_ids"=>["1",
"3"]}

There''s something very basic that I''m missing here.  I want to
be able
to grab these values in my controller method and do something like:

params[@current_job][:target_list_ids].each {
//Do what''s necessary to link up my models via the has_many :though 
relationship by populating the "through" table.
}

Is my problem that I''m naming my checkboxes using 
@current_job[target_list_ids], and this is being literally interpreted 
and ending up in the view that way?

I hope this makes sense.  I think I am generally confused about how the 
check_box and check_box_tag helpers work.

Thanks,
Wes

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I have the same problem does anyone else have any suggestions on this?

Wes Gamble wrote:
> All,
> 
> I''m populating a view with checkboxes in a list.  I want to be
able to
> assign to my has_many relationship using the post values of these 
> checkboxes.  Essentially, I want to populate the relationship table 
> which will create the correct join values in my model.
> 
..snip..
> I hope this makes sense.  I think I am generally confused about how the 
> check_box and check_box_tag helpers work.
> 
> Thanks,
> Wes
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Posted via http://www.ruby-forum.com/.

JoeWooten wrote:
> I have the same problem does anyone else have any suggestions on this?
> 
> Wes Gamble wrote:
>> All,
>> 
>> I''m populating a view with checkboxes in a list.  I want to be
able to
>> assign to my has_many relationship using the post values of these 
>> checkboxes.  Essentially, I want to populate the relationship table 
>> which will create the correct join values in my model.
>> 
> 
> ..snip..
> 
>> I hope this makes sense.  I think I am generally confused about how the
>> check_box and check_box_tag helpers work.
>> 
>> Thanks,
>> Wes
Joe,

I got this working but don''t have time to post the code right now. 
Send
an email to weyus at att dot net and please remind me to post my 
solution.

Thanks,
Wes

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

On this day, 16-July-2006 4:48 AM,  JoeWooten wrote:
> I have the same problem does anyone else have any suggestions on this?
> 
> Wes Gamble wrote:
>> All,
>>
>> I''m populating a view with checkboxes in a list.  I want to be
able to
>> assign to my has_many relationship using the post values of these 
>> checkboxes.  Essentially, I want to populate the relationship table 
>> which will create the correct join values in my model.
>>
> 
> ..snip..
> 
>> I hope this makes sense.  I think I am generally confused about how the
>> check_box and check_box_tag helpers work.
>>
>> Thanks,
>> Wes
> 
Found these links.
http://jrhicks.net/96 --> checkout the pdf
http://wiki.rubyonrails.com/rails/pages/CheckboxHABTM
http://wiki.rubyonrails.com/rails/pages/has_and_belongs_to_many ---> the 
main page

P.V.Anthony

Joe,

Here''s what I ended up doing...

Job and TargetList are related through their association object. 
Basically, in the form, I''m manipulating indices of an array that I
then
use to populate the "through" object.  So I''m not attempting
to
manipulate the "child" or "parent" model directly.

Hope this helps,
Wes

Job model:

has_many :job_list_associations, :foreign_key => :JobReferenceNumber
has_many :target_lists, :through => :job_list_associations, :source => 
:target_list

TargetList model:

has_many :job_list_associations, :foreign_key => :DataSetID
has_many :jobs, :through => :job_list_associations, :source => :job

Job model:

  public
  def target_list_ids
    ids = Array.new
    unless target_lists.nil?
      target_lists.each do |list|
        ids << list.DataSetID
      end
    end
    ids
  end

  public
  def target_list_ids=(list_array)
    list_array.each do |id|
      target_lists << TargetList.find(id)
    end
  end

View:
<TD class="list-data">
  <%= check_box_tag("current_job[target_list_ids][]",
tlist.DataSetID,
      @current_job.target_lists.include?(tlist), :class =>
''list-data'')
%>
      <%= tlist.Alias %>
</TD>

Controller calls this method in the job model to manage the 
associations:

  public
  def set_list_relationships(selected_lists)
    #Find all of the existing associations before we save anything
    current_job_lists = Array.new
    JobListAssociation.find_all_by_JobReferenceNumber(self.JobReferenceNumber, 
:select => ''DataSetID'').each { |jla|
      current_job_lists << jla.DataSetID
    }

    #For each submitted list identifier...
    selected_lists.each { |value|
      #...add the association if it doesn''t exist and record that it
was
submitted
      unless current_job_lists.include?(value)
        jla = JobListAssociation.new
        jla.JobReferenceNumber = self.JobReferenceNumber
        jla.DataSetID = value
        jla.FaxDataTable = TargetList.find(value).Alias
        jla.save!
      end
    }

    #Finally, remove all of the lists that were already stored but were 
not selected this time around.
    (current_job_lists - selected_lists).each { |value|
      JobListAssociation.destroy_all("JobReferenceNumber = 
#{self.JobReferenceNumber} AND DataSetId = #{value}")
    }
  end

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