Message on AR::UnknownAttributeError should include the class name of a record

[yuki24]

This would be helpful if 2 models have an attribute that has a similar name to the other. e.g.
before:

User.new(name: "Yuki Nishijima", projects_attributes: [name: "kaminari"])
# => ActiveRecord::UnknownAttributeError: unknown attribute: name

after:

User.new(name: "Yuki Nishijima", projects_attributes: [name: "kaminari"])
# => ActiveRecord::UnknownAttributeError: unknown attribute on User: name

[yuki24]

rebased twice so far. Any chance this pull request could be merged into master?

[sgrif]

Should this handle ActiveModel::MissingAttributeError, which is raised by many methods called by Active Record internally? https://github.com/rails/rails/blob/master/activemodel/lib/active_model/attribute_methods.rb#L476-L478

[yuki24]

It's a good point, I'll change ActiveModel::MissingAttributeError to include the class name as well!

[sgrif]

❤️

[sgrif]

[]= is the easiest way to raise for testing

[yuki24]

After spending some time on this, It turns out that ActiveRecord::Attribute::Null, which eventually raises ActiveModel::MissingAttributeError when []= is called, can't put a class name into the message, as it doesn't know about the class it belongs to.

To make ActiveRecord::Attribute::Null aware of the class name, we have to change these changes:

1. ActiveRecord::AttributeSet has to pass a class name to ActiveRecord::Attribute::Null
2. ActiveRecord::AttributeSet has to know about the class name to do 1
3. ActiveRecord::AttributeSet::Builder has to give a class name to an attribute set, to do 2
4. ActiveRecord::ModelSchema has to pass a class name to the AttributeSet::Builder to do 3

Is that a good idea? Probably not. I think we should change only ActiveRecord::UnknownAttributeError for now. Does it make sense or should we just close this request?

[sgrif]

Yes I do not think we should pass the class to any of those subclasses. I
think just handling the active record error is fine for now.
On Oct 18, 2014 9:39 PM, "Yuki Nishijima" notifications@github.com wrote:

After spending some time on this, It turns out that
ActiveRecord::Attribute::Null will raise
ActiveModel::MissingAttributeError when []= is called, but it can't put a
class name into the message, as ActiveRecord::Attribute::Null doesn't
know about the class it belongs to.

To make ActiveRecord::Attribute::Null be aware of the class name, we have
to change these changes:

1. ActiveRecord::AttributeSet has to pass a class name to
   ActiveRecord::Attribute::Null
2. ActiveRecord::AttributeSet has to know about the class name to do 1
3. ActiveRecord::AttributeSet::Builder has to give a class name to an
   attribute set, to do 2
4. ActiveRecord::ModelSchema have to pass a class name to the
   AttributeSet::Builder to do 3

Is that a good idea? Probably not. I think we should change only
ActiveRecord::UnknownAttributeError for now. Does it make sense or should
we just close this request?

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Reply to this email directly or view it on GitHub
#17019 (comment).

[senny]

@yuki24 thank you 💛 reworded the message slightly and shortened the CHANGELOG.

[yuki24]

Thank you! ❤️ ❤️ ❤️

[rebyn]

Awesome change 👍.