Hello,
I’m having a touch time with the implementation of as has_many
relationship between 3 models:
Here are my models files
product.rb contains(note that I’m extending the product model from the
plugin substruct):
require_dependency RAILS_ROOT +
“/vendor/plugins/substruct/app/models/product”
class Product < Item
has_many :videos
end
video_displays.rb contains
class VideoDisplay < ActiveRecord::Base
has_many :videos
Required input
validates_presence_of :display_name
validates_uniqueness_of :display_name
end
video.rb contains
class Video < ActiveRecord::Base
belongs_to :video_displays
belongs_to :products
validates_uniqueness_of :filename
end
I created using the MySQL administrator two foreign keys in the videos
table out of columns i provided in the migration:
create_table :videos do |t|
t.column "filename", :string
t.column "video_display_id", :integer
t.column "product_id", :integer
t.timestamps
end
Finally I attempt to load a video object into the product and
video_displays models with the following code in my save action for the
products_controller.rb
@product.attributes = params[:product]
if @product.save
# Save product tags
# Our method doesn't save tags properly if the product doesn't
already exist.
# Make sure it gets called after the product has an ID
@product.tag_ids = params[:product][:tag_ids] if
params[:product][:tag_ids]
# Load Video path names into product model
video_errors = []
@display =
VideoDisplay.find_by_display_name(params[:video_display])
if (!@display.nil?)
params[:video].each do |v|
if v[:filename]
new_video =
Video.find_or_create_by_filename(v[:filename])
if new_video.save
@display.videos << new_video
@product.videos << new_video
else
video_errors.push(new_video.filename)
end
end
end
else
video_errors.push(“Choosen display not found
params[:video_display]”)
end
…
I get the following error:
ActiveRecord::AssociationTypeMismatch in Admin/productsController#save
Video expected, got Video
RAILS_ROOT: /Users/mkp/eCommerce/substruct_rel_1-0-a3
Application Trace | Framework Trace | Full Trace
vendor/rails/activerecord/lib/active_record/associations/association_proxy.rb:150:in
raise_on_type_mismatch' vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:24:in<<’
vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:23:in
each' vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:23:in<<’
vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb:66:in
transaction' vendor/rails/activerecord/lib/active_record/transactions.rb:80:intransaction’
vendor/rails/activerecord/lib/active_record/transactions.rb:100:in
transaction' vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:22:in<<’
app/controllers/admin/products_controller.rb:48:in save' app/controllers/admin/products_controller.rb:43:ineach’
app/controllers/admin/products_controller.rb:43:in `save’
line 48 is
@product.videos << new_video
so my association with display_videos is cool. When I check the videos
table with mysql, it shows the new row created with the video_display_id
properly set to the desired id in the video_displays table. However, the
association with products is not happening. Here are my hunches:
The Product model is an extension of the a model found in my substruct
plugin which itself is derived from a model called Item. I suspect that
this complication is confound RAILS somehow?!?
I created the foreign key association outside to RAILS using the MySQL
administrator gui which I suspect may not be compatible with the RAILS
interface:
When I startup script/server, I get the following warning:
WARNING: You’re using the Ruby-based MySQL library that ships with
Rails. This library is not suited for production. Please install the
C-based MySQL library instead (gem install mysql). Maybe this has
something to do with the problem.
I"m new to all this so please, any comments would be helpful and greatly
appreciated.
Thank you for your attention,
Marc