Currently `ActiveModel::Model` is defined as the minimum API to talk
with Action Pack and Action View.
Its name suggests it can be included to create Active Record type
models, but for creating models it's probably too minimal. For example
it's very common to include ActiveModel::Attributes as well.
By moving `ActiveModel::Model`'s implementation to a new
`ActiveModel::API` we keep a definition of the minimum API to talk with
Action Pack and Action View.
For `ActiveModel::Model` we only need to include `ActiveModel::API`.
This will allow adding more funcationality to `ActiveModel::Model` while
keeping backwards compatibility.
Co-authored-by: Nathaniel Watts <1141717+thewatts@users.noreply.github.com>
According to pr #22443 in the guides there's always a dollar sign before every command, so why is in the main README a `$` and in every submodule a `%`?
Just eye candy..
I think we are better off leaving `sudo` outside of the documented
way of installing gems (`activerecord`, `actionpack`, …).
We don’t want newbies to think that `sudo` is required or, even worse, than
they actually have to type `[sudo] gem install`.
In most scenarios, `sudo` is not needed to install gems, and people who do
need it, probably already know about it.
What do you think? 😁
The four code samples that fail to run are:
- Add attribute magic to objects. Fixed by introducing a Person
instance variable.
- Tracking value changes. Fixed by replacing `attr_accessor` with
`define_attribute_methods`, providing getter and setter methods
for `name` and providing the missing `Person#save` method. A
call to `Person#save` has to precede the `person.name = 'robert'`
assignment, if we want `previous_changes` to include 'bob'.
- Adding `errors` interface to objects. Fixed by introducing a
Person instance variable, assigning `nil` to its name and calling
`Person#validate!`.
- Custom validators. Fixed by defining `HasNameValidator` before
it is used by `ValidatorPerson`.
All the code samples can now be run smoothly.
Call Dirty#changes_applied in Person#save, instead of modifying instance vars.
