Is there a way to get a collection of all the Models in your Rails app

Question

Is there a way that you can get a collection of all of the Models in your Rails app   Basically  can I do the likes of  -  Models each do  model    puts model class name end

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With Rails 6  Zetiwerk became the default code loader   For eager loading  try   Zeitwerk  Loader eager load all   Then  ApplicationRecord descendants

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The whole answer for Rails 3  4 and 5 is   If cache classes is off  by default it s off in development  but on in production    Rails application eager load    Then   ActiveRecord  Base descendants   This makes sure all models in your application  regardless of where they are  are loaded  and any gems you are using which provide models are also loaded   This should also work on classes that inherit from ActiveRecord  Base  like ApplicationRecord in Rails 5  and return only that subtree of descendants   ApplicationRecord descendants   If you d like to know more about how this is done  check out ActiveSupport  DescendantsTracker

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Yes there are many ways you can find all model names but what I did in my gem model info is   it will give you all the models even included in the gems   array      model array    Rails application eager load  array ActiveRecord  Base descendants collect  x  x to s if x table exists   compact array each do  x    if  x split       last split      first     HABTM       model array push x    end    model array delete  ActiveRecord  SchemaMigration   end   then simply print this    model array

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ActiveRecord  Base connection tables

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I think  hnovick s solution is a cool one if you dont have table-less models  This solution would work in development mode as well  My approach is subtly different though -  ActiveRecord  Base connection tables map  x x classify safe constantize  compact   classify is well supposed to give you the name of the class from a string properly  safe constantize ensures that you can turn it into a class safely without throwing an exception  This is needed in case you have database tables which are not models  compact so that any nils in the enumeration are removed

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If you want just the Class names   ActiveRecord  Base descendants map   f  puts f    Just run it in Rails console  nothing more  Good luck   EDIT   sj26 is right  you need to run this first before you can call descendants   Rails application eager load

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I m just throwing this example here if anyone finds it useful  Solution is based on this answer https   stackoverflow com a 10712838 473040    Let say you have a column public uid that is used as a primary ID to outside world  you can findjreasons why you would want to do that here   Now let say you ve introduced this field on bunch of existing Models and now you want to regenerate all the records that are not yet set  You can do that like this     lib tasks data integirity rake namespace  di do   namespace  public uids do     desc  Data Integrity  genereate public uid for any model record that doesn t have value of public uid      task generate   environment do       Rails application eager load        ActiveRecord  Base          descendants          select   f  f attribute names include   public uid              each do  m             m where public uid  nil  each    mi  puts  Generating public uid for   m  id   mi id    mi generate public uid  mi save         end      end    end  end   you can now run rake di public uids generate

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ActiveRecord  Base connection tables map do  model    model capitalize singularize camelize end   will return    Article    MenuItem    Post    ZebraStripePerson     Additional information If you want to call a method on the object name without model string unknown method or variable errors use this   model classify constantize attribute names

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I can t comment yet  but I think sj26 answer should be the top answer  Just a hint   Rails application eager load  unless Rails configuration cache classes ActiveRecord  Base descendants

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Dir foreach    Rails root to s  app models   do  model path    next unless model path match   rb      model class   model path gsub   rb        classify constantize   puts model class end   This will give to you all the model classes you have on your project

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can check this    models   ActiveRecord  Base connection tables collect  t  t underscore singularize camelize

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This works for Rails 3 2 18  Rails application eager load   def all models   models   Dir    Rails root  app models      rb   map do  m      m chomp   rb   camelize split       last   end end

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Just in case anyone stumbles on this one  I ve got another solution  not relying on dir reading or extending the Class class     ActiveRecord  Base send  subclasses   This will return an array of classes  So you can then do  ActiveRecord  Base send  subclasses  map  amp  name

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def load models in development   if Rails env     development      load models for Rails root      Rails application railties engines each do  r        load models for r root      end   end end  def load models for root    Dir glob    root  app models      rb   do  model path      begin       require model path     rescue         ignore     end   end end

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Here s a solution that has been vetted with a complex Rails app  the one powering Square   def all models     must eager load all the classes      Dir glob    RAILS ROOT  app models      rb   do  model path      begin       require model path     rescue         ignore     end   end     simply return them   ActiveRecord  Base send  subclasses  end   It takes the best parts of the answers in this thread and combines them in the simplest and most thorough solution  This handle cases where your models are in subdirectories  use set table name etc

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I ve tried so many of these answers unsuccessfully in Rails 4  wow they changed a thing or two for god sakes  I decided to add my own  The ones that called ActiveRecord  Base connection and pulled the table names worked but didn t get the result I wanted because I ve hidden some models  in a folder inside of app models   that I didn t want to delete   def list models   Dir glob    Rails root  app models   rb   map  x  x split      last split      first camelize  end   I put that in an initializer and can call it from anywhere  Prevents unnecessary mouse-usage

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Assuming all models are in app models and you have grep  amp  awk on your server  majority of the cases      extract lines that match specific string  and print 2nd word of each line results    grep -r   lt  ActiveRecord  Base  app models    awk   print  2    model names   results split   n     It it faster than  Rails application eager load  or looping through each file with Dir   EDIT   The disadvantage of this method is that it misses models that indirectly inherit from ActiveRecord  e g  FictionalBook  lt  Book   The surest way is Rails application eager load   ActiveRecord  Base descendants map  amp  name   even though it s kinda slow

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This worked for me  Special thanks to all the posts above  This should return a collection of all your models   models       Dir glob    Rails root  app models      rb   do  model path    temp   model path split    models       models push temp last gsub    rb        camelize constantize rescue nil end

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The Rails implements the method descendants  but models not necessarily ever inherits from ActiveRecord  Base  for example  the class that includes the module ActiveModel  Model will have the same behavior as a model  just doesn t will be linked to a table   So complementing what says the colleagues above  the slightest effort would do this   Monkey Patch of class Class of the Ruby   class Class   def extends  constant     ancestors include  constant  if constant    self   end end   and the method models  including ancestors  as this   The method Module constants returns  superficially  a collection of symbols  instead of constants  so  the method Array select can be substituted like this monkey patch of the Module   class Module    def demodulize     splitted trail   self to s split           constant   splitted trail last      const get constant  if defines  constant    end   private  demodulize    def defines  constant  verbose false     splitted trail   constant split           trail name   splitted trail first      begin       trail   const get trail name  if Object send  const defined   trail name        splitted trail slice 1  splitted trail length - 1  each do  constant name          trail   trail send  const defined   constant name    trail const get constant name    nil       end       true if trail     rescue Exception   gt  e        stderr puts  Exception recovered when trying to check if the constant     constant    is defined    e   if verbose     end unless constant empty    end    def has constants      true if constants any    end    def nestings counted      amp block     trail   self to s     collected          recursivityQueue           constants each do  const name        const name   const name to s       const for try      trail     const name         constant   const for try constantize        begin         constant sym   constant to s to sym         if constant  amp  amp   counted include  constant sym            counted  lt  lt  constant sym           if  constant is a  Module     constant is a  Class               value   block given    block call constant    constant             collected  lt  lt  value if value              recursivityQueue push                 constant  constant                counted  counted                block  block                if constant has constants            end         end       rescue Exception       end      end      recursivityQueue each do  data        collected concat data  constant  nestings data  counted    amp data  block       end      collected   end  end   Monkey patch of String   class String   def constantize     if Module defines  self        Module const get self     else       demodulized   self split       last       Module const get demodulized  if Module defines  demodulized      end   end end   And  finally  the models method  def models     preload only models   application config eager load paths   model eager load paths   application eager load     models   Module nestings do  const      const if const is a  Class   amp  amp  const    ActiveRecord  SchemaMigration  amp  amp   const extends  ActiveRecord  Base     const include  ActiveModel  Model     end end  private    def application       Rails application   end    def model eager load paths     eager load paths   application config eager load paths collect do  eager load path        model paths   application config paths  app models   collect do  model path          eager load path if Regexp new     model path      match eager load path        end     end flatten compact   end

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Just came across this one  as I need to print all models with their attributes built on  Aditya Sanghi s comment    ActiveRecord  Base connection tables map  x x classify safe constantize  compact each   model  print   n n  model name  model new attributes each  a b  print   n  a

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In just one line    ActiveRecord  Base subclasses map  amp  name

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To avoid pre-load all Rails  you can do this   Dir glob    Rails root  app models      rb   each   f  require dependency f      require dependency f  is the same that Rails application eager load  uses  This should avoid already required file errors   Then you can use all kind of solutions to list AR models  like ActiveRecord  Base descendants

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Module constants select    c   eval c  is a  Class   amp  amp   eval c   lt  ActiveRecord  Base

User · Answer

On one line  Dir  app models    rb   map   f  File basename f        camelize constantize

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This seems to work for me     Dir glob RAILS ROOT     app models   rb   each    file  require file      models   Object subclasses of ActiveRecord  Base    Rails only loads models when they are used  so the Dir glob line  requires  all the files in the models directory   Once you have the models in an array  you can do what you were thinking  e g  in view code     lt    models each do  v    gt     lt li gt  lt    h v to s   gt  lt  li gt   lt   end   gt

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I looked for ways to do this and ended up choosing this way   in the controller       data tables   ActiveRecord  Base connection tables  in the view     lt    data tables each do  dt     gt     lt br gt     lt    dt   gt     lt   end   gt     lt br gt    source  http   portfo li rails 348561-how-can-one-list-all-database-tables-from-one-project

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For Rails5 models are now subclasses of ApplicationRecord so to get list of all models in your app you do   ApplicationRecord descendants collect    type  type name     Or shorter   ApplicationRecord descendants collect  amp  name    If you are in dev mode  you will need to eager load models before   Rails application eager load

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EDIT  Look at the comments and other answers  There are smarter answers than this one  Or try to improve this one as community wiki   Models do not register themselves to a master object  so no  Rails does not have the list of models   But you could still look in the content of the models directory of your application     Dir foreach    RAILS ROOT  app models   do  model path          end   EDIT  Another  wild  idea would be to use Ruby reflection to search for every classes that extends ActiveRecord  Base  Don t know how you can list all the classes though     EDIT  Just for fun  I found a way to list all classes  Module constants select    c   eval c  is a  Class     EDIT  Finally succeeded in listing all models without looking at directories  Module constants select do  constant name    constant   eval constant name   if not constant nil  and constant is a  Class and constant superclass    ActiveRecord  Base     constant   end end   If you want to handle derived class too  then you will need to test the whole superclass chain  I did it by adding a method to the Class class   class Class   def extend  klass      not superclass nil  and   superclass    klass or superclass extend  klass     end end  def models    Module constants select do  constant name      constant   eval constant name     if not constant nil  and constant is a  Class and constant extend  ActiveRecord  Base     constant     end   end end

[ruby-on-rails] Is there a way to get a collection of all the Models in your Rails app?

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