Rails - Feb 2006 - How can I access the value of params[:tags] in my validate function?

I would like to have tags mandatory in my app.
  
  The following keeps giving me error that params is nill.
  
   def validate()
    if (@params[:tags])
        errors.add(@params[:tags], ":tags must be entered ")
     end
   end
  
  Why cannot I access params in my model class?
  The field for tags is called "tags" 
  
  How else can I add an error using errors.add?
  
  I finally got to use flash[:notice] in my controller but I''m sure
there is a better way to do this.
  
  Many thanks to the member of this great list for their assistance.
  
  Frank
  
		
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On Feb 13, 2006, at 10:34 AM, softwareengineer 99 wrote:
> I would like to have tags mandatory in my app.
>
> The following keeps giving me error that params is nill.
>
>  def validate()
>   if (@params[:tags])
>       errors.add(@params[:tags], ":tags must be entered ")
>    end
>  end
>
> Why cannot I access params in my model class?
> The field for tags is called "tags"
>
> How else can I add an error using errors.add?
>
> I finally got to use flash[:notice] in my controller but I''m sure
> there is a better way to do this.
>
> Many thanks to the member of this great list for their assistance.
>
> Frank
>
> Yahoo! Mail
> Use Photomail to share photos without annoying attachments.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails

Frank-

	You cannot access params in your model because it breaks MVC. Your  
model should not know anything about params or session at all. You  
will have to refactor the method to pass in the params to a method on  
your model from your controller. Or rethink the problem you are  
trying to solve.

Cheers-
-Ezra Zygmuntowicz
Yakima Herald-Republic
WebMaster
http://yakimaherald.com
509-577-7732
ezra@yakima-herald.com

I''m trying to pass the name of a column to update along with
it''s new
value.  Given these as my params:

{
"id"=>"3",
"field"=>"asset_type",
"selected"=>"item8",
"controller"=>"inventory",
"action"=>"update"
}

asset_type is a column in my database, and the following works:

   def update
     @asset = Asset.find(params[:id])
     @asset.asset_type = params[:selected]
     @asset.save
     @asset.reload
     render_text @asset.asset_type
   end

Is there a way to replace the two instances of @asset.asset_type with  
something along the lines of @asset.params[:field] (or @asset.send 
(params[:field]) )?  It''s the syntax that''s killing me...

- Peter

On Tue, 2006-02-14 at 15:36 -0800, Peter T Bosse II
wrote:
> I''m trying to pass the name of a column to update along with
it''s new
> value.  Given these as my params:
> 
> {
> "id"=>"3",
> "field"=>"asset_type",
> "selected"=>"item8",
> "controller"=>"inventory",
> "action"=>"update"
> }
> 
> asset_type is a column in my database, and the following works:
> 
>    def update
>      @asset = Asset.find(params[:id])
>      @asset.asset_type = params[:selected]
>      @asset.save
>      @asset.reload
>      render_text @asset.asset_type
>    end
> 
> Is there a way to replace the two instances of @asset.asset_type with  
> something along the lines of @asset.params[:field] (or @asset.send 
> (params[:field]) )?  It''s the syntax that''s killing me...
> 
----
id=>3  means a single row in your table
selected=>''item8'' is probably confusing because it
isn''t a column. You
should probably identify it as ''asset_type'' and forget the
extra work of
''field=>'' as that doesn''t clarify anything...only
confuses it. Check the
''link_to'' statement where this all comes from and fix it
there.

Craig

On Feb 14, 2006, at 3:48 PM, Craig White wrote:
> On Tue, 2006-02-14 at 15:36 -0800, Peter T Bosse II wrote:
>> I''m trying to pass the name of a column to update along with
it''s new
>> value.  Given these as my params:
>>
>> {
>> "id"=>"3",
>> "field"=>"asset_type",
>> "selected"=>"item8",
>> "controller"=>"inventory",
>> "action"=>"update"
>> }
>>
>> asset_type is a column in my database, and the following works:
>>
>>    def update
>>      @asset = Asset.find(params[:id])
>>      @asset.asset_type = params[:selected]
>>      @asset.save
>>      @asset.reload
>>      render_text @asset.asset_type
>>    end
>>
>> Is there a way to replace the two instances of @asset.asset_type with
>> something along the lines of @asset.params[:field] (or @asset.send
>> (params[:field]) )?  It''s the syntax that''s killing
me...
>>
> ----
> id=>3  means a single row in your table
> selected=>''item8'' is probably confusing because it
isn''t a column. You
> should probably identify it as ''asset_type'' and forget
the extra
> work of
> ''field=>'' as that doesn''t clarify
anything...only confuses it.
> Check the
> ''link_to'' statement where this all comes from and fix it
there.
----

Thanks for the response!

I guess I should have been more clear as to what I''m trying to do.  I  
have an Ajax function that would like to repurpose for use on all of  
my pop-up fields (I''m not using link_to).  In this particular  
situation, I know I''m trying to update the column
"asset_type", but
I''d like to re-use this code to be able to update any arbitrary  
column (which is named in :field) with the results of ":selected".   
Is this possible?

- Peter

> I guess I should have been more clear as to what I''m trying to do.
I
> have an Ajax function that would like to repurpose for use on all of
> my pop-up fields (I''m not using link_to).  In this particular
> situation, I know I''m trying to update the column
"asset_type", but
> I''d like to re-use this code to be able to update any arbitrary
> column (which is named in :field) with the results of
":selected".
> Is this possible?
>
> - Peter
Peter,

Haven''t tested this exactly, only on a dummy class, but I''m
pretty
certain it will work with little modification if any:

    def update
      @asset = Asset.find(params[:id])
      @assent.send("#{params[:field]}=".to_sym, params[:selected])
      @asset.save
      @asset.reload
      render_text @asset.send(params[:field])
    end

Joe Noon

>> I guess I should have been more clear as to what I''m trying to
do.  I
>> have an Ajax function that would like to repurpose for use on all of
>> my pop-up fields (I''m not using link_to).  In this particular
>> situation, I know I''m trying to update the column
"asset_type", but
>> I''d like to re-use this code to be able to update any
arbitrary
>> column (which is named in :field) with the results of
":selected".
>> Is this possible?
>>
>> - Peter
>
> Peter,
>
> Haven''t tested this exactly, only on a dummy class, but
I''m pretty
> certain it will work with little modification if any:
>
>     def update
>       @asset = Asset.find(params[:id])
>       @asset.send("#{params[:field]}=".to_sym, params[:selected])
>       @asset.save
>       @asset.reload
>       render_text @asset.send(params[:field])
>     end
>
> Joe Noon
----

Perfect!  Thank you so much!

- Peter