RoR newbie needs help with instance variables and view

Rails
1

Hello all,

I’m a RoR newbie and just wondering if anyone out there can help me. I
have a view page where I send over two instance variables like so:

Controller

def new
@category = Category.find(:all, :order => “description asc”)
@product = Product.new
end
def create
@product = Product.new(params[:product])
if @product.save
flash[:notice] = ‘Product was successfully created.’
redirect_to :action => ‘timeframe’
else
render :action => ‘new’

end

end
View page snippet:

<%= form_tag( { :action => ‘create’}, :multipart => true ) %>

<%= error_messages_for ‘product’ %>

Product Model Validation:

belongs_to :category, :class_name => “Category”, :foreign_key =>
“category_uid”
validates_presence_of :description, :abbreviation, :price, :staffprice
validates_numericality_of :price, :reducedprice, :staffprice

Now when I have a validation error, I get this particular error:

You have a nil object when you didn’t expect it!
You might have expected an instance of Array.
The error occured while evaluating nil.each

Extracted source (around line #16):

13:
14:

Meal Categories <% @category.each do |category| %> "> <%=category.description %> <%end%>

15:
16: <% @category.each do |category| %>
17: <option value=<%= category.id %>">
18: <%=category.description %>
19:

My problem is I just don’t know my way around this. I haven’t really
found that much information on this. Could anyone please help and point
me in the right direction. Thanks for your help
2

The problem here is that you’re loading the categories in the ‘new’
action but your form error page is shown in the ‘create’ action -
notice that your ‘create’ has no reference to @category in it. Now,
you are calling ‘render :action => ‘new’’ which will cause the create
template to be rendered, but it will not load the categories.

You have a couple of options - you could put another ‘@categories =…’
statement in the ‘create’ action, but that would mean duplicating
code. The best options are to either use a before_filter (see http://
api.rubyonrails.org/classes/ActionController/Filters/
ClassMethods.html), or you can compress your create/new actions into
one:

def new
@categories = Category.find(:all, :order => “description asc”)
if request.post?
@product = Product.new(params[:product])
if @product.save
flash[:notice] = ‘Product was successfully created.’
redirect_to :action => ‘timeframe’
end
else
@product = Product.new
end
end

You can then just put ‘new’ as your form action.

Hope that helps,

Steve

3

On Jan 30, 10:16 am, DLo [email protected] wrote:

end
View page snippet:

My problem is I just don’t know my way around this. I haven’t really
found that much information on this. Could anyone please help and point
me in the right direction. Thanks for your help

–
Posted viahttp://www.ruby-forum.com/.

While you are creating the Product, you are not creating and
associating the Categories, or populating the instance variable for
the view.
Try something like:

Controller

def create
@product = Product.new(params[:product])
if @product.save
@category = @product.category # Add this line.
flash[:notice] = ‘Product was successfully created.’
redirect_to :action => ‘timeframe’
else
render :action => ‘new’
end
end

4

Thanks so much for the quick reply. You guys are the greateset.
Appecreciate it.