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An ActiveRecord emulating Tableless model which works with Rails 3.1
class Tableless < ActiveRecord::Base
def self.column(name, sql_type = nil, default = nil, null = true)
columns << ActiveRecord::ConnectionAdapters::Column.new( name.to_s, default, sql_type.to_s, null )
end
def self.columns()
@columns ||= [];
end
def self.columns_hash
h = {}
for c in self.columns
h[c.name] = c
end
return h
end
def self.column_defaults
Hash[self.columns.map{ |col|
[col.name, col.default]
}]
end
def self.descends_from_active_record?
return true
end
def persisted?
return false
end
# override the save method to prevent exceptions
def save( validate = true )
validate ? valid? : true
end
end
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matpowel Jul 23, 2011

Put this in your app/models dir and then extend it to get a tableless model that still supports all the associations like has_many, belongs_to etc, validations and basically smells like a real model.

We use it a fair bit for things like filter models, giving us very clean view and controller code.

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matpowel commented Jul 23, 2011

Put this in your app/models dir and then extend it to get a tableless model that still supports all the associations like has_many, belongs_to etc, validations and basically smells like a real model.

We use it a fair bit for things like filter models, giving us very clean view and controller code.

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RobertDeRose Sep 6, 2011

Could you give a quick little example of a model using this? does it look like this?
clase SomeModel
extend Tableless

belongs_to :AnyOldActiveRecordModel
has_many :SomeOtherACModel

attr_accessor :some_column_1, :some_column_2

end

or do you have to use the column syntax like the old rails 2.3 way?

Could you give a quick little example of a model using this? does it look like this?
clase SomeModel
extend Tableless

belongs_to :AnyOldActiveRecordModel
has_many :SomeOtherACModel

attr_accessor :some_column_1, :some_column_2

end

or do you have to use the column syntax like the old rails 2.3 way?

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ragrawal Nov 3, 2011

Hi I am having trouble using this. It seems rails is trying to hit DB and is not able to find "tableless" table

Ritesh

ragrawal commented Nov 3, 2011

Hi I am having trouble using this. It seems rails is trying to hit DB and is not able to find "tableless" table

Ritesh

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matpowel Nov 8, 2011

Here's an example use:

class CreditCard < Tableless
belongs_to :payment

column :payment_id, :integer
column :first_name, :string
column :last_name, :string
column :number, :string
column :month, :date
column :year, :date
column :verification_value, :string
end

p = Payment.new( :users => 2, :price => 100.00, :credit_card => { :first_name => "Test", :last_name => "User", :month => 5, :year => 2013 } )
p.credit_card.valid? # add validations to make this useful
p.credit_card.verification_value = 123

etc.

What are you trying to do with your models?

Owner

matpowel commented Nov 8, 2011

Here's an example use:

class CreditCard < Tableless
belongs_to :payment

column :payment_id, :integer
column :first_name, :string
column :last_name, :string
column :number, :string
column :month, :date
column :year, :date
column :verification_value, :string
end

p = Payment.new( :users => 2, :price => 100.00, :credit_card => { :first_name => "Test", :last_name => "User", :month => 5, :year => 2013 } )
p.credit_card.valid? # add validations to make this useful
p.credit_card.verification_value = 123

etc.

What are you trying to do with your models?

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betamatt Nov 22, 2011

I believe #save takes a hash in 3.1 instead of a boolean.

  # override the save method to prevent exceptions
  def save( opts = {} )
    options = { :validate => true }.merge(opts)
    options[:validate] ? valid? : true
  end

I believe #save takes a hash in 3.1 instead of a boolean.

  # override the save method to prevent exceptions
  def save( opts = {} )
    options = { :validate => true }.merge(opts)
    options[:validate] ? valid? : true
  end
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ragrawal Jan 19, 2012

I tried this and was able to get it working. However, something funny is happening. Let A is a tableless model and has many B. Also assume a is an instance of A. if I do a.b then I get an empty array. However if I do a.b.limit(100) then I get all the valid objects. Any idea what happening over here.

I tried this and was able to get it working. However, something funny is happening. Let A is a tableless model and has many B. Also assume a is an instance of A. if I do a.b then I get an empty array. However if I do a.b.limit(100) then I get all the valid objects. Any idea what happening over here.

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matpowel Jan 19, 2012

@ragrawal if you post your model code here I'll take a look at it

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matpowel commented Jan 19, 2012

@ragrawal if you post your model code here I'll take a look at it

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clickworkorange May 24, 2012

@ragrawal, @matpowel: I've been trying to use this in a Rails 3.2 app and also get "No such table: 'tableless'" - what am I missing?

@ragrawal, @matpowel: I've been trying to use this in a Rails 3.2 app and also get "No such table: 'tableless'" - what am I missing?

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matpowel May 24, 2012

@mikrogroove as I said to @ragrawal, post a simplified version of your model code and I'll have a look. We're using that code as-is in 3.2 and it works perfectly.

Owner

matpowel commented May 24, 2012

@mikrogroove as I said to @ragrawal, post a simplified version of your model code and I'll have a look. We're using that code as-is in 3.2 and it works perfectly.

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clickworkorange May 24, 2012

The base model:

class Tableless < ActiveRecord::Base

  def self.table_name
      self.name.tableize
  end

  def self.columns
    @columns ||= [];
  end

  def self.column(name, sql_type = nil, default = nil, null = true)
    columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, default, sql_type.to_s, null)
  end

  def self.columns_hash
    @columns_hash ||= Hash[columns.map { |column| [column.name, column] }]
  end

  def self.column_names
    @column_names ||= columns.map { |column| column.name }
  end

  def self.column_defaults
    @column_defaults ||= columns.map { |column| [column.name, nil] }.inject({}) { |m, e| m[e[0]] = e[1]; m }
  end

  def self.descends_from_active_record?
    return true
  end

  def persisted?
    return false
  end

  # override the save method to prevent exceptions
  def save( opts = {} )
    options = { :validate => true }.merge(opts)
    options[:validate] ? valid? : true
  end
end

And an example use:

class Stuff < Tableless
  has_many :stuff_things
  has_many :things, :through => :stuff_things

  column :id, :integer
  column :name, :string
  column :value, :string

  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end
end

The base model:

class Tableless < ActiveRecord::Base

  def self.table_name
      self.name.tableize
  end

  def self.columns
    @columns ||= [];
  end

  def self.column(name, sql_type = nil, default = nil, null = true)
    columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, default, sql_type.to_s, null)
  end

  def self.columns_hash
    @columns_hash ||= Hash[columns.map { |column| [column.name, column] }]
  end

  def self.column_names
    @column_names ||= columns.map { |column| column.name }
  end

  def self.column_defaults
    @column_defaults ||= columns.map { |column| [column.name, nil] }.inject({}) { |m, e| m[e[0]] = e[1]; m }
  end

  def self.descends_from_active_record?
    return true
  end

  def persisted?
    return false
  end

  # override the save method to prevent exceptions
  def save( opts = {} )
    options = { :validate => true }.merge(opts)
    options[:validate] ? valid? : true
  end
end

And an example use:

class Stuff < Tableless
  has_many :stuff_things
  has_many :things, :through => :stuff_things

  column :id, :integer
  column :name, :string
  column :value, :string

  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end
end
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clickworkorange May 24, 2012

@matpowel: Many thanks for taking the time to help! I'm suspecting that my problem has to do with not instantiating the model? My plan is to add to this "fake" table at boot, using values from a configuration file...

@matpowel: Many thanks for taking the time to help! I'm suspecting that my problem has to do with not instantiating the model? My plan is to add to this "fake" table at boot, using values from a configuration file...

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clickworkorange May 24, 2012

I should add that with the example above I get "No such table: 'stuffs'" and not "tablelesses".

I should add that with the example above I get "No such table: 'stuffs'" and not "tablelesses".

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matpowel May 24, 2012

This all works for me.. note I removed your initialize method as it's superfluous, that's what the default one will do but without the unsafe eval.

class Thing < Tableless
  belongs_to :stuff_thing

  column :stuff_thing_id, :integer
  column :name, :string
end

class StuffThing < Tableless
  belongs_to :stuff
  has_many :things

  column :stuff_id, :integer
end

class Stuff < Tableless
  has_many :stuff_things
  has_many :things, :through => :stuff_things

  column :id, :integer
  column :name, :string
  column :value, :string
end

And then you can use them as normal, except that ARel won't chain the has many through very well, I don't know whether your stuff_things etc are actually real AR models, if they are it will work normally.

1.8.7 :064 >   s = Stuff.new( :id => 10, :name => "foo", :value => "bar" )
WARNING: Can't mass-assign protected attributes: id
 => #<Stuff id: nil, name: "foo", value: "bar"> 
1.8.7 :065 > s.stuff_things << StuffThing.new( :stuff => s )
 => [#<StuffThing stuff_id: nil>] 
1.8.7 :067 > s.stuff_things.length
 => 1
s.things << Thing.new( :name => "wild thing" )
 => [#<Thing stuff_thing_id: nil, name: "wild thing">]
Owner

matpowel commented May 24, 2012

This all works for me.. note I removed your initialize method as it's superfluous, that's what the default one will do but without the unsafe eval.

class Thing < Tableless
  belongs_to :stuff_thing

  column :stuff_thing_id, :integer
  column :name, :string
end

class StuffThing < Tableless
  belongs_to :stuff
  has_many :things

  column :stuff_id, :integer
end

class Stuff < Tableless
  has_many :stuff_things
  has_many :things, :through => :stuff_things

  column :id, :integer
  column :name, :string
  column :value, :string
end

And then you can use them as normal, except that ARel won't chain the has many through very well, I don't know whether your stuff_things etc are actually real AR models, if they are it will work normally.

1.8.7 :064 >   s = Stuff.new( :id => 10, :name => "foo", :value => "bar" )
WARNING: Can't mass-assign protected attributes: id
 => #<Stuff id: nil, name: "foo", value: "bar"> 
1.8.7 :065 > s.stuff_things << StuffThing.new( :stuff => s )
 => [#<StuffThing stuff_id: nil>] 
1.8.7 :067 > s.stuff_things.length
 => 1
s.things << Thing.new( :name => "wild thing" )
 => [#<Thing stuff_thing_id: nil, name: "wild thing">]
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stevemartin Nov 14, 2012

Thanks for this gist, I made this demo with it: https://github.com/stevemartin/tableless_form

Thanks for this gist, I made this demo with it: https://github.com/stevemartin/tableless_form

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