Ruby class extension in Rails works when declared locally, returns `nil` when imported from `/lib/`

TLDR: A hash extension works flawlessly, returning the desired output, when included locally in my Mailer, but always returns nil when imported from a module in lib/, even though the class method is successfully loaded.

When I declare the extension in my mailer.rb file, before my class definition, as in:

class Hash
 def try_deep(*fields)
 ...
 end
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

it works flawlessly, but this is bad practice. I thought it better to declare the extension in /lib/core_ext/hash/try_deep.rb and then require it in the Mailer, as in:

/lib/core_ext/hash/try_deep.rb:

module CoreExtensions
 module Hash
 module TryDeep
 def try_deep(*fields)
 ...
 end
 end
 end
end

/my_mailer.rb:

require 'core_ext/hash/try_deep'

class MyMailer < ApplicationMailer
 Hash.include CoreExtensions::Hash::TryDeep
 some_hash.try_deep(:some_key)
end

edited Nov 15 '18 at 2:10

asked Nov 15 '18 at 1:27

James

1418

1

Side question: Are you implementing Hash#dig?

– Marcin Kołodziej
Nov 15 '18 at 3:01

@MarcinKołodziej Good question. The reason I'm implementing this is to be able to safely dig for attributes in a mixed-object-version environment. Older objects are missing certain newer attributes. Hash#dig, while it seems great at first, doesn't solve my problem because it throws an error rather than 'nil' when it digs for a key that doesn't exist. For my idiosyncratic use-case (sending an email), 'nil' is what I want when a key isn't found.

– James
Nov 16 '18 at 4:30

It seems to return nil to me when a key does not exist: a: 1.dig(:b) => nil

– Marcin Kołodziej
Nov 16 '18 at 4:39

add a comment |

When I declare the extension in my mailer.rb file, before my class definition, as in:

class Hash
 def try_deep(*fields)
 ...
 end
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

it works flawlessly, but this is bad practice. I thought it better to declare the extension in /lib/core_ext/hash/try_deep.rb and then require it in the Mailer, as in:

/lib/core_ext/hash/try_deep.rb:

module CoreExtensions
 module Hash
 module TryDeep
 def try_deep(*fields)
 ...
 end
 end
 end
end

/my_mailer.rb:

require 'core_ext/hash/try_deep'

class MyMailer < ApplicationMailer
 Hash.include CoreExtensions::Hash::TryDeep
 some_hash.try_deep(:some_key)
end

edited Nov 15 '18 at 2:10

asked Nov 15 '18 at 1:27

James

1418

1

Side question: Are you implementing Hash#dig?

– Marcin Kołodziej
Nov 15 '18 at 3:01

@MarcinKołodziej Good question. The reason I'm implementing this is to be able to safely dig for attributes in a mixed-object-version environment. Older objects are missing certain newer attributes. Hash#dig, while it seems great at first, doesn't solve my problem because it throws an error rather than 'nil' when it digs for a key that doesn't exist. For my idiosyncratic use-case (sending an email), 'nil' is what I want when a key isn't found.

– James
Nov 16 '18 at 4:30

It seems to return nil to me when a key does not exist: a: 1.dig(:b) => nil

– Marcin Kołodziej
Nov 16 '18 at 4:39

add a comment |

When I declare the extension in my mailer.rb file, before my class definition, as in:

class Hash
 def try_deep(*fields)
 ...
 end
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

it works flawlessly, but this is bad practice. I thought it better to declare the extension in /lib/core_ext/hash/try_deep.rb and then require it in the Mailer, as in:

/lib/core_ext/hash/try_deep.rb:

module CoreExtensions
 module Hash
 module TryDeep
 def try_deep(*fields)
 ...
 end
 end
 end
end

/my_mailer.rb:

require 'core_ext/hash/try_deep'

class MyMailer < ApplicationMailer
 Hash.include CoreExtensions::Hash::TryDeep
 some_hash.try_deep(:some_key)
end

edited Nov 15 '18 at 2:10

asked Nov 15 '18 at 1:27

James

1418

When I declare the extension in my mailer.rb file, before my class definition, as in:

class Hash
 def try_deep(*fields)
 ...
 end
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

it works flawlessly, but this is bad practice. I thought it better to declare the extension in /lib/core_ext/hash/try_deep.rb and then require it in the Mailer, as in:

/lib/core_ext/hash/try_deep.rb:

module CoreExtensions
 module Hash
 module TryDeep
 def try_deep(*fields)
 ...
 end
 end
 end
end

/my_mailer.rb:

require 'core_ext/hash/try_deep'

class MyMailer < ApplicationMailer
 Hash.include CoreExtensions::Hash::TryDeep
 some_hash.try_deep(:some_key)
end

ruby-on-rails ruby class class-extensions

edited Nov 15 '18 at 2:10

asked Nov 15 '18 at 1:27

James

1418

edited Nov 15 '18 at 2:10

asked Nov 15 '18 at 1:27

James

1418

edited Nov 15 '18 at 2:10

asked Nov 15 '18 at 1:27

James

1418

asked Nov 15 '18 at 1:27

James

1418

asked Nov 15 '18 at 1:27

James

1418

1

Side question: Are you implementing Hash#dig?

– Marcin Kołodziej
Nov 15 '18 at 3:01

@MarcinKołodziej Good question. The reason I'm implementing this is to be able to safely dig for attributes in a mixed-object-version environment. Older objects are missing certain newer attributes. Hash#dig, while it seems great at first, doesn't solve my problem because it throws an error rather than 'nil' when it digs for a key that doesn't exist. For my idiosyncratic use-case (sending an email), 'nil' is what I want when a key isn't found.

– James
Nov 16 '18 at 4:30

It seems to return nil to me when a key does not exist: a: 1.dig(:b) => nil

– Marcin Kołodziej
Nov 16 '18 at 4:39

add a comment |

1

Side question: Are you implementing Hash#dig?

– Marcin Kołodziej
Nov 15 '18 at 3:01

@MarcinKołodziej Good question. The reason I'm implementing this is to be able to safely dig for attributes in a mixed-object-version environment. Older objects are missing certain newer attributes. Hash#dig, while it seems great at first, doesn't solve my problem because it throws an error rather than 'nil' when it digs for a key that doesn't exist. For my idiosyncratic use-case (sending an email), 'nil' is what I want when a key isn't found.

– James
Nov 16 '18 at 4:30

It seems to return nil to me when a key does not exist: a: 1.dig(:b) => nil

– Marcin Kołodziej
Nov 16 '18 at 4:39

Side question: Are you implementing Hash#dig?

– Marcin Kołodziej
Nov 15 '18 at 3:01

@MarcinKołodziej Good question. The reason I'm implementing this is to be able to safely dig for attributes in a mixed-object-version environment. Older objects are missing certain newer attributes. Hash#dig, while it seems great at first, doesn't solve my problem because it throws an error rather than 'nil' when it digs for a key that doesn't exist. For my idiosyncratic use-case (sending an email), 'nil' is what I want when a key isn't found.

– James
Nov 16 '18 at 4:30

It seems to return nil to me when a key does not exist: a: 1.dig(:b) => nil

– Marcin Kołodziej
Nov 16 '18 at 4:39

add a comment |

1 Answer
1

active

oldest

votes

You need to inject your custom method into Hash outside of your class:

my_mailer.rb:

require 'core_ext/hash/try_deep'

class Hash
 include CoreExtensions::Hash::TryDeep
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

add a comment |

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1 Answer
1

active

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1 Answer
1

active

oldest

votes

You need to inject your custom method into Hash outside of your class:

my_mailer.rb:

require 'core_ext/hash/try_deep'

class Hash
 include CoreExtensions::Hash::TryDeep
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

add a comment |

You need to inject your custom method into Hash outside of your class:

my_mailer.rb:

require 'core_ext/hash/try_deep'

class Hash
 include CoreExtensions::Hash::TryDeep
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

add a comment |

You need to inject your custom method into Hash outside of your class:

my_mailer.rb:

require 'core_ext/hash/try_deep'

class Hash
 include CoreExtensions::Hash::TryDeep
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

You need to inject your custom method into Hash outside of your class:

my_mailer.rb:

require 'core_ext/hash/try_deep'

class Hash
 include CoreExtensions::Hash::TryDeep
end

class MyMailer < ApplicationMailer
 some_hash.try_deep(:some_key)
end

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

answered Nov 15 '18 at 3:41

Ilya Konyukhov

2,3081718

add a comment |

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