undefined method `include?' for nil:NilClass in 1.2.0 but not 1.1.0

[chriscummings]

I'm using DataMapper with Sinatra and I've found that I keep getting the following error with DataMapper 1.2.0:

NoMethodError at /tag 
undefined method `include?' for nil:NilClass

    file: resource.rb
    location: block in attributes=
    line: 332

Backtrace

/Users/chris/Desktop/chriscummings-Blog-9331485/controllers/tag.rb in new

    tag = Tag.new({

/Users/chris/Desktop/chriscummings-Blog-9331485/controllers/tag.rb in block in <top (required)>

    tag = Tag.new({

/Users/chris/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/webrick/httpserver.rb in service

    si.service(req, res)

/Users/chris/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/webrick/httpserver.rb in run

    server.service(req, res)

/Users/chris/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/webrick/server.rb in block in start_thread

    block ? block.call(sock) : run(sock)

There's nothing wrong with the file mentioned controllers/tag.rb. I get the same error with any path that tries to create/update/delete a record. If I force gem 'data_mapper', '= 1.1.0' in my Gemfile I don't experience the issue.

Potentially pertinent code

---

controllers/tag.rb
Like I said, the error pops up on any path that attempts to edit a record. Additionally, the require_administrative_privileges and tag_validate! methods don't do anything magical and commenting them out makes no difference.

post '/tag/?' do
  require_administrative_privileges
  tag_validate!(params)

  #Ensure uniques
  tag = Tag.first(:name => params[:name])
  if tag
    halt 409, "Tag \"" + tag.name + "\" already exists!"
  end

  tag = Tag.new({
    :name => params[:name],
    :created_at => Time.now
  })

  if tag.save
    status(201)
    redirect '/tag'
  else
    halt 409, tag.errors.inspect
  end
end

My DataMapper models file

class Post
  include DataMapper::Resource

  property :id,         Serial
  property :created_at, DateTime
  property :updated_at, DateTime
  property :title,      Text
  property :body,       Text
  property :body_md,   Text
  property :slug,       Text

  has n, :posttags
  has n, :tags, :through => :posttags
end

class Tag
  include DataMapper::Resource

  property :id,         Serial
  property :created_at, DateTime
  property :updated_at, DateTime
  property :name,       Text

  has n, :posttags
  has n, :posts, :through => :posttags
end


class Posttag
  include DataMapper::Resource

  property :id,         Serial

  belongs_to :tag, :key => true
  belongs_to :post, :key => true
end

class Page
  include DataMapper::Resource

  property :id,         Serial
  property :created_at, DateTime
  property :updated_at, DateTime
  property :title,      Text
  property :body,       Text
  property :body_md,   Text
  property :slug,       Text
end

[solnic]

You forgot to call DataMapper.finalize

[chriscummings]

Right you are. Thanks, solnic!

Looking at the datamapper.org page again, the necessity or even the existence of this method isn't super obvious. It might be beneficial to document it a little more loudly for TL;DR folks like myself or maybe raise an exception?

As far as I'm concerned this issue can be can be closed. I don't know what the GitHub etiquette is on closing issues on other's repos.

[emmanuel]

Hi Chris,

On Oct 26, 2011, at 10:42 PM, Chris Cummings wrote:

I'm using DataMapper with Sinatra and I've found that I keep getting the following error with DataMapper 1.2.0:

Call DataMapper.finalize to get everything ready for use.

Behavior changed a bit in 1.2.0—calling DataMapper.finalize used to be strongly recommended, but is now required.

NoMethodError at /tag 
undefined method `include?' for nil:NilClass

   file: resource.rb
   location: block in attributes=
   line: 332

The failure behavior could be improved...

Hope that helps,
Emmanuel

[chriscummings]

Hope that helps

Indeed it does. Thanks, Emmanuel.

[youens]

Ran into this as well... a more obvious failure behavior would be great!

[solnic]

@youens failure behavior will be improved in 1.3.0

[gtd]

I appreciate the issue being here as I found it quickly when I ran into the same thing.

[shangyiss]

Finalize Models
After declaring all of the models, you should finalize them:

DataMapper.finalize

This issue is troubled me more times,thanks .