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Gonzalo

2009-May-20 10:09 UTC

habtm association and accepts_nested_attributes_for

hi all,

i have the following models:

  class Developer < ActiveRecord::Base
    has_and_belongs_to_many :projects
    accepts_nested_attributes_for :projects
  end

  class Project < ActiveRecord::Base
    has_and_belongs_to_many :developers
    accepts_nested_attributes_for :developers
  end


the following code:

  params = { ''form'' => { ''name'' =>
''gonzalo'', ''dni'' =>
''12876365x'',
               ''projects_attributes'' => {
                 ''new_01'' => { ''name''
=> ''Sioux'', ''cost'' =>
''25000'' },
                 ''new_02'' => { ''name''
=> ''Apache'', ''cost'' =>
''3400''}}}}
  Developer.create(params[''form''])


will create a new Developer and two new Projects and the corresponding
association between Developer and Projects.

then, I add a new Developer using the same mechanism:

  params = { ''form'' => { ''name'' =>
''paul'', ''dni'' =>
''17002034z'',
                 ''projects_attributes'' => {
                   ''1'' => { ''name'' =>
''ZZZZ'', ''cost'' =>
''25000'' },
                   ''2'' => { ''name'' =>
''YYYY'', ''cost'' =>
''3400''}}}}
  Developer.create(params[''form''])


following NestedAttributes documentation... this code should add a new
Developer (paul) and link it against the two already created Projects
with ids 1 and 2. Besides, this code should modiify projects names
from Sioux and Apache to ZZZZ and YYYY respectively.

the real result is that a new Developer (paul) is added but linked
against two new Projects (ZZZZ and YYYY)


am I doing something wrong? should i use another approach to face this
problem? is accept_nested_attributes_for feature compatible with habtm
associations?

and last... what if i just want to create a new Developer (paul) that
is associated with the already created Projects with ids 1 and 2? The
following code won''t work:

  params = { ''form'' => { ''name'' =>
''paul'', ''dni'' =>
''17002034z'',
                   ''projects_attributes'' => {
                     ''1'' => { },
                     ''2'' => { }}}}
  Developer.create(params[''form''])


thanks in advance for your help!
regards.

Franco Catena

2009-May-20 14:40 UTC

head link

Re: habtm association and accepts_nested_attributes_for

Try using the ID inside (this works for me):

params = { ''form'' => { ''name'' =>
''paul'', ''dni'' =>
''17002034z'',
                 ''projects_attributes'' => {
                   ''1'' => { ''id'' =>
''1'', ''name'' => ''ZZZZ'',
''cost'' =>
''25000'' },
                   ''2'' => { ''id'' =>
''2'', ''name'' => ''YYYY'',
''cost'' =>
''3400''}}}}

An element with an ID is considered to be updated instead of created.

On May 20, 7:09 am, Gonzalo
<gonzalo.llore...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:> hi all,
>
> i have the following models:
>
>   class Developer < ActiveRecord::Base
>     has_and_belongs_to_many :projects
>     accepts_nested_attributes_for :projects
>   end
>
>   class Project < ActiveRecord::Base
>     has_and_belongs_to_many :developers
>     accepts_nested_attributes_for :developers
>   end
>
> the following code:
>
>   params = { ''form'' => { ''name''
=> ''gonzalo'', ''dni'' =>
''12876365x'',
>                ''projects_attributes'' => {
>                  ''new_01'' => {
''name'' => ''Sioux'',
''cost'' => ''25000'' },
>                  ''new_02'' => {
''name'' => ''Apache'',
''cost'' =>
> ''3400''}}}}
>   Developer.create(params[''form''])
>
> will create a new Developer and two new Projects and the corresponding
> association between Developer and Projects.
>
> then, I add a new Developer using the same mechanism:
>
>   params = { ''form'' => { ''name''
=> ''paul'', ''dni'' =>
''17002034z'',
>                  ''projects_attributes'' => {
>                    ''1'' => { ''name''
=> ''ZZZZ'', ''cost'' =>
''25000'' },
>                    ''2'' => { ''name''
=> ''YYYY'', ''cost'' =>
''3400''}}}}
>   Developer.create(params[''form''])
>
> following NestedAttributes documentation... this code should add a new
> Developer (paul) and link it against the two already created Projects
> with ids 1 and 2. Besides, this code should modiify projects names
> from Sioux and Apache to ZZZZ and YYYY respectively.
>
> the real result is that a new Developer (paul) is added but linked
> against two new Projects (ZZZZ and YYYY)
>
> am I doing something wrong? should i use another approach to face this
> problem? is accept_nested_attributes_for feature compatible with habtm
> associations?
>
> and last... what if i just want to create a new Developer (paul) that
> is associated with the already created Projects with ids 1 and 2? The
> following code won''t work:
>
>   params = { ''form'' => { ''name''
=> ''paul'', ''dni'' =>
''17002034z'',
>                    ''projects_attributes'' => {
>                      ''1'' => { },
>                      ''2'' => { }}}}
>   Developer.create(params[''form''])
>
> thanks in advance for your help!
> regards.

Rails - May 2009 - habtm association and accepts_nested_attributes_for

habtm association and accepts_nested_attributes_for

Re: habtm association and accepts_nested_attributes_for