Ruby on Rails

Hello,

I just stumbled upon a behaviour about associations I do not really understand why Rails/ActiveRecord cannot get the connection. Using activerecord (4.2.0.beta2).

To describe it, lets work with theses models:

class User < ActiveRecord::Base
    has_many :project_participations
    has_many :projects, through: :project_participations, inverse_of: :users
end

class ProjectParticipation < ActiveRecord::Base
    belongs_to :user
    belongs_to :project

    enum role: { member: 0, manager: 1 }
end

class Project < ActiveRecord::Base
    has_many :project_participations
    has_many :users, through: :project_participations, inverse_of: :projects
end

A user can participate in many projects with a role as a member or a manager. The connecting model is called ProjectParticipation.

I now have a problem using the associations on unsaved objects. The following commands work like I think they should work:

# first example

u = User.new
p = Project.new

u.projects << p

u.projects
=> #<ActiveRecord::Associations::CollectionProxy [#<Project id: nil>]>

u.project_participations
=> #<ActiveRecord::Associations::CollectionProxy [#<ProjectParticipation id: nil, user_id: nil, project_id: nil, role: nil>]>

So far so good - AR created the ProjectParticipation by itself and I can access the projects of a user with u.projects.

But it does not work if I create the ProjectParticipation by myself:

# second example

u = User.new
pp = ProjectParticipation.new
p = Project.new

pp.project = p # assign project to project_participation

u.project_participations << pp # assign project_participation to user

u.project_participations
=> #<ActiveRecord::Associations::CollectionProxy [#<ProjectParticipation id: nil, user_id: nil, project_id: nil, role: nil>]>

u.projects
=> #<ActiveRecord::Associations::CollectionProxy []>

Why are the projects empty? I cannot access the projects by u.projects like before, even the ProjectParticipation is there.

But if I go through the participations directly, the project shows up:

u.project_participations.map(&:project)
=> [#<Project id: nil>]
Shouldn't it work like the first example directly:
u.projects returning me all projects not depending on whether I create the join object by myself or not? Or how can I make AR aware of this?

Colin Law wrote:
> That tells you it is rails 4.0.0 as activemodel is one of the
> components.  However, rather than seeing what versions are installed
> (there could be more than one version of the gems installed) look in
> the file Gemfile.lock in the applications root folder and you will see
> what versions it /requires/.

I have several GIT entries in the Gemfile.lock file and a list of gems
after the following lines, but this list looks much more extensive than
'gem list' shows ...

GEM
   remote: https://rubygems.org/
   specs:
     <list of gems>

Then under DEPENDENCIES, I see ...

rails (= 3.2.13)

Does that explain my rails version? I don't see any references to 4.0.0.

> I suggest you work right through a good tutorial such as
> railstutorial.org (which is free to use online) which will show you
> the basics of rails.  A few days spend doing that will save you time
> in the long run.

Yes, I've already found that and been reading, thanks.

> If you want this for development work then I suggest you install rails
> using rvm [1]
> That will give you a complete working setup in a few minutes.

I used rvm to install same ruby-1.9.3-p392 as the VPS, following a doc
here...

https://www.digitalocean.com/community/tutorials/how-to-install-rails-apache-and-mysql-on-ubuntu-with-passenger

After all setup in Apache, I am getting this Passenger application error
in the browser....

cannot load such file -- bundler/setup (LoadError)
 
/usr/share/ruby-rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in
`require'
 
/usr/share/ruby-rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in
`require'
 
/usr/share/ruby-rvm/gems/ruby-1.9.3-p392/gems/passenger-4.0.53/lib/phusion_passenger/loader_shared_helpers.rb:263:in
`block in run_load_path_setup_code'
 
/usr/share/ruby-rvm/gems/ruby-1.9.3-p392/gems/passenger-4.0.53/lib/phusion_passenger/loader_shared_helpers.rb:366:in
`running_bundler'
 
/usr/share/ruby-rvm/gems/ruby-1.9.3-p392/gems/passenger-4.0.53/lib/phusion_passenger/loader_shared_helpers.rb:261:in
`run_load_path_setup_code'
 
/usr/share/ruby-rvm/gems/ruby-1.9.3-p392/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:100:in
`preload_app'
 
/usr/share/ruby-rvm/gems/ruby-1.9.3-p392/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:158:in
`<module:App>'
 
/usr/share/ruby-rvm/gems/ruby-1.9.3-p392/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:29:in
`<module:PhusionPassenger>'
 
/usr/share/ruby-rvm/gems/ruby-1.9.3-p392/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:28:in
`<main>'

Perhaps I need to get some more gems installed? I did a 'gem install
bundle' and still get the error. My gem list is this so far on the dev
server I am trying to setup, not sure if this error is affecting things
as well...

root@media:/etc/apache2# gem list
/usr/share/ruby-rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/yaml.rb:56:in
`<top (required)>':
It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your ruby.

*** LOCAL GEMS ***

bundle (0.0.1)
bundler (1.7.4)
daemon_controller (1.2.0)
passenger (4.0.53)
rack (1.5.2)
rake (10.3.2)

On the production server, I have...

*** LOCAL GEMS ***

activemodel (4.0.0)
activerecord (4.0.0)
activerecord-deprecated_finders (1.0.3)
activerecord-mysql-adapter (0.0.1)
activesupport (4.0.0)
arel (4.0.0)
atomic (1.1.13)
bigdecimal (1.1.0)
builder (3.1.4)
bundler (1.3.5)
i18n (0.6.5)
io-console (0.3)
json (1.5.5)
minitest (4.7.5, 2.5.1)
multi_json (1.7.9)
mysql (2.9.1)
rake (0.9.2.2)
rdoc (3.9.5)
thread_safe (0.1.2)
tzinfo (0.3.37)

But again the list in the Gemfile.lock file lists many more. Just trying
to get a grasp of where to go from here, what is need to get this copy
to run, appreciate any help!

Ruby on Rails developer for Expanding Start up (Ruby on Rails, Python, Clojure), London

Location: London, Farringdon

Salary: £35-70k plus Stock Options and Friday Lunch Club

Join Growing Dev Team at Highly Successful Start Up (Ruby on Rails, Python, Clojure) 

The Company

The client is a start-up that aims to make space rental as easy as booking a hotel room. Their platform seamlessly connects landlords' vacant spaces to people with great ideas and their vision is to create a global network of spaces so people can make their idea travel. Founded only a couple of years ago this company now has a generous amount of funding and is expanding rapidly.

With the aim to go global this is a great time to join a growing company and be one of the first in the engineering team.

The Role

The stack uses Ruby for most of the backend and Rails, SCSS, Foundation & vanilla HS are the main frontend tools but they aren't dogmatic about language choice. They will consider people from a Ruby, Python or Clojure background and are open to using whatever language works best for the task in hand!

You will be helping to build software for the tenants, ensuring that they are matched to their ideal space and it is as easy as possible to create this process whilst avoiding pen and paper, and also the landlords who will want to use their space data to get an insight in the market.

Skills Required

·         3+ years' experience in RoR, Python or Clojure but you must be happy to work in RoR

·         A can do attitude and willingness to work hard and help others

·         Enthusiasm to join a growing team and help drive the company forward

Benefits

·         Strong basic salary

·         Your pick of apple hardware

·         Stock options

·         Small Company Culture

·         Great office – diet coke on tap and group lunches on a friday

If this role interests you and you think that you could be a good match then please get in touch for more information:

Ysemay Hackett-Evans

[e] ysemay@oxfordknight.co.uk

[t] 02034755018

class User < ActiveRecord::Base
    has_many :project_participations
    has_many :projects, through: :project_participations, inverse_of: :users
end

class ProjectParticipation < ActiveRecord::Base
    belongs_to :user
    belongs_to :project

    enum role: { member: 0, manager: 1 }
end

class Project < ActiveRecord::Base
    has_many :project_participations
    has_many :users, through: :project_participations, inverse_of: :projects
end

# first example

u = User.new
p = Project.new

u.projects << p

u.projects
=> #<ActiveRecord::Associations::CollectionProxy [#<Project id: nil>]>

u.project_participations
=> #<ActiveRecord::Associations::CollectionProxy [#<ProjectParticipation id: nil, user_id: nil, project_id: nil, role: nil>]>

# second example

u = User.new
pp = ProjectParticipation.new
p = Project.new

pp.project = p # assign project to project_participation

u.project_participations << pp # assign project_participation to user

u.project_participations
=> #<ActiveRecord::Associations::CollectionProxy [#<ProjectParticipation id: nil, user_id: nil, project_id: nil, role: nil>]>

u.projects
=> #<ActiveRecord::Associations::CollectionProxy []>

u.project_participations.map(&:project)
=> [#<Project id: nil>]
Shouldn't it work like the first example directly:
u.projects returning me all projects not depending on whether I create the join object by myself or not? Or how can I make AR aware of this?

My boss is finally willing to listen to moving to a quality open sourced platform for our e-commerce web site, but she needs 'concrete examples' to believe that moving to ruby on rails is a good solution.  And she needs 'e-commerce' pages (i.e. telling her twitter is built in rails doesn't impress her), preferably in the natural food industry.

We currently have a company that 'built' our website in PHP and we don't own our code, nor do we have access to the data (which drives me batty).  They were recently purchased and the new owner is attempting to green mail us and it's an opportunity to get my boss to move to a better base where we own all the data and the code of the web site.  I'm a 'pre-beginner' in rails.  I know enough to get started, but not enough to build a truly dynamic website, let alone a fully functional e-commerce with a front and back end.

I was hoping people could give me some examples or a site that lists sites built in rails?

My boss is finally willing to listen to moving to a quality open sourced platform for our e-commerce web site, but she needs 'concrete examples' to believe that moving to ruby on rails is a good solution.  And she needs 'e-commerce' pages (i.e. telling her twitter is built in rails doesn't impress her), preferably in the natural food industry.

We currently have a company that 'built' our website in PHP and we don't own our code, nor do we have access to the data (which drives me batty).  They were recently purchased and the new owner is attempting to green mail us and it's an opportunity to get my boss to move to a better base where we own all the data and the code of the web site.  I'm a 'pre-beginner' in rails.  I know enough to get started, but not enough to build a truly dynamic website, let alone a fully functional e-commerce with a front and back end.

I was hoping people could give me some examples or a site that lists sites built in rails?

My boss is finally willing to listen to moving to a quality open sourced platform for our e-commerce web site, but she needs 'concrete examples' to believe that moving to ruby on rails is a good solution.  And she needs 'e-commerce' pages (i.e. telling her twitter is built in rails doesn't impress her), preferably in the natural food industry.

We currently have a company that 'built' our website in PHP and we don't own our code, nor do we have access to the data (which drives me batty).  They were recently purchased and the new owner is attempting to green mail us and it's an opportunity to get my boss to move to a better base where we own all the data and the code of the web site.  I'm a 'pre-beginner' in rails.  I know enough to get started, but not enough to build a truly dynamic website, let alone a fully functional e-commerce with a front and back end.

I was hoping people could give me some examples or a site that lists sites built in rails?

My boss is finally willing to listen to moving to a quality open sourced platform for our e-commerce web site, but she needs 'concrete examples' to believe that moving to ruby on rails is a good solution.  And she needs 'e-commerce' pages (i.e. telling her twitter is built in rails doesn't impress her), preferably in the natural food industry.

We currently have a company that 'built' our website in PHP and we don't own our code, nor do we have access to the data (which drives me batty).  They were recently purchased and the new owner is attempting to green mail us and it's an opportunity to get my boss to move to a better base where we own all the data and the code of the web site.  I'm a 'pre-beginner' in rails.  I know enough to get started, but not enough to build a truly dynamic website, let alone a fully functional e-commerce with a front and back end.

I was hoping people could give me some examples or a site that lists sites built in rails?

Hi there.

I'm interested in extracting parts of my application to a local gem in vendor/gems. The reason I haven't done that yet is that I'm not sure about what would be the best way to handle auto-reloading for such gems...

I'm pretty aware of the argument that if you're doing TDD you don't need auto-reloading, but still I'm interested in auto-reloading.

I've taken a look at a few solutions like require_reloader and gem_reloader but I'd prefer to use some more robust approach if possible, as I wasn't much comfortable with their implementation...

Is there any official way for developing Rails applications with local gems so that their code could be automatically reloaded in some robust/easy way?

Thanks in advance,

Rodrigo.

I have a single table in which I store favourite dishes of users. A user can have more than one entries in the table. I have generated a view to show all the entries in the table but how do I create a view to show just the list of users. I don't have a table saving the users so I have to use DISTINCT to get the names of the users from my one and only table

I appraoched this by creating a new route
/foodsIlike/user_list

get '/foodsIlike/user_list' => 'foodsIlike#user_list', :as => 'user_list'

instead of going to the user_list it tries to find a record with :id=user_list as that is what it would do to show one record

We are seeking an assistant software developer to support our development

Experience of Ruby and Rails, PostgreSQL, coffeescript, jquery would be be preferential and Java for Android would be beneficial. We will consider candidates without Ruby on Rails experience, but must have a willingness to learn. Must be well-organised and have strong professional skills as you be interacting with client requests. Interest in environmental innovation desired.

We are a fast growing company that has spin-out of research from Oxford University that is bringing innovative solutions for improving car and building energy performance.

We have several commercially ready software applications and a pipeline of new products currently in research and development. We are looking for a London or Oxford-based developer able to give 30-50 hours a month and there is opportunity for growth.

Start date: September. Please send cv to: kevin.etienne(at)pilio-ltd.com.

class CreateContacts < ActiveRecord::Migration

  def change

    create_table :contacts do |t|

      t.string :name

      t.string :phone_number

      t.string :email

      t.timestamps

    end

  end

end