Rails - Apr 2006 - ActionView::Helpers::FormHelper instance methods should take an object reference rather than an object_name.

Hi

ActionView::Helpers::FormHelper methods (e.g. #text_field,
#check_box...) take object_name as an argument. From this argument
they infer a name that is supposed to contains the reference to the
relevant object.

I can''t see why the FormHelper methods were designed that way.
Compared to simply passing them a reference, the current way seems too
complicated and an invitation to problems or at least limitations.

For example, if you call text_field("post", "title"), the
method would
look for a @post instance variable. Imagine you were using a local
variable for storing the relevant object, instead of an instance
variable. If text_field took a reference, you would just call it with
text_field(post, :title). However, since it takes a string an infers a
reference name, you now have to change your assigned names or at least
create new aliases to your existing names.

To sum up, I can''t see any advantages to the object_name approach, I
don''t understand why FormHelper was initially designed that way, so I
think it should be changed so as to be more convenient and flexible.
What do you think?

Regards,
Alder

On Saturday 08 April 2006 17:50, Alder Green wrote:
> Hi
> 
> ActionView::Helpers::FormHelper methods (e.g. #text_field,
> #check_box...) take object_name as an argument. From this argument
> they infer a name that is supposed to contains the reference to the
> relevant object.
> 
> I can''t see why the FormHelper methods were designed that way.
> Compared to simply passing them a reference, the current way seems too
> complicated and an invitation to problems or at least limitations.
> 
> For example, if you call text_field("post", "title"),
the method would
> look for a @post instance variable. Imagine you were using a local
> variable for storing the relevant object, instead of an instance
> variable. If text_field took a reference, you would just call it with
> text_field(post, :title). However, since it takes a string an infers a
> reference name, you now have to change your assigned names or at least
> create new aliases to your existing names.
> 
> To sum up, I can''t see any advantages to the object_name approach,
I
> don''t understand why FormHelper was initially designed that way,
so I
> think it should be changed so as to be more convenient and flexible.
> What do you think?
> 
> Regards,
> Alder
It provides some useful additions. Like mass assigning with .attributes=, and
the use of validations without worrying about anything. Look at my post on the
list I made 2 minutes before you did, which explains a bit about validations.

In situations where you encounter limitations, use the text_field_tag method
instead.

<...>
> For example, if you call text_field("post", "title"),
the method would
> look for a @post instance variable. Imagine you were using a local
> variable for storing the relevant object, instead of an instance
> variable. If text_field took a reference, you would just call it with
> text_field(post, :title). However, since it takes a string an infers a
> reference name, you now have to change your assigned names or at least
> create new aliases to your existing names.
<...>

... or simply use text_field_tag instead of text_field.

> To sum up, I can''t see any advantages to the object_name approach,
I
> don''t understand why FormHelper was initially designed that way,
so I
> think it should be changed so as to be more convenient and flexible.
> What do you think?
Nothing should be changed, When you want to work with model''s
attributes you use text_field (which makes updates as simple as
update_attributes params[:model]) ,
when you want something ''flexible'' you use text_field_tag.


Regards,
Rimantas
--
http://rimantas.com/