The solution presented in this patch is not efficient. We should replace it
in the near future. The following needs to be worked out:
* Is `@attributes` storing the Ruby or SQL representation?
* `cacheable_column?` is broken but `hstore` and `json` rely on that behavior
Refs #15369.
/cc @sgrif @rafaelfranca
After ad7b5efb55bcc2e0ccd3e7f22a81e984df8676d1, which changed how
has_an_belongs_to_many used to work, we start raising an error when
redefining the same has_an_belongs_to_many association. This commits fix
that regression.
[Fixes#14983]
As a result of all of the refactoring that's been done, it's now
possible for us to define a public API to allow users to specify
behavior. This is an initial implementation so that I can work off of it
in smaller pieces for additional features/refactorings.
The current behavior will continue to stay the same, though I'd like to
refactor towards the automatic schema detection being built off of this
API, and add the ability to opt out of automatic schema detection.
Use cases:
- We can deprecate a lot of the edge cases around types, now that there
is an alternate path for users who wish to maintain the same behavior.
- I intend to refactor serialized columns to be built on top of this
API.
- Gem and library maintainers are able to interact with `ActiveRecord`
at a slightly lower level in a more stable way.
- Interesting ability to reverse the work flow of adding to the schema.
Model can become the single source of truth for the structure. We can
compare that to what the database says the schema is, diff them, and
generate a migration.
* * *
This bug can be triggered when serializing record R (the instance) of type C
(the class), provided that the following conditions are met:
1. The name of one or more columns/attributes on C/R matches an existing private
method on C (e.g. those defined by `Kernel`, such as `format`).
2. The attribute methods have not yet been generated on C.
In this case, the matching private methods will be called by the serialization
code (with no arguments) and their return values will be serialized instead. If
the method requires one or more arguments, it will result in an `ArgumentError`.
This regression is introduced in d1316bb.
* * *
Attribute methods (e.g. `#name` and `#format`, assuming the class has columns
named `name` and `format` in its database table) are lazily defined. Instead of
defining them when a the class is defined (e.g. in the `inherited` hook on
`ActiveRecord::Base`), this operation is deferred until they are first accessed.
The reason behind this is that is defining those methods requires knowing what
columns are defined on the database table, which usually requires a round-trip
to the database. Deferring their definition until the last-possible moment helps
reducing unnessary work, especially in development mode where classes are
redefined and throw away between requests.
Typically, when an attribute is first accessed (e.g. `a_book.format`), it will
fire the `method_missing` hook on the class, which triggers the definition of
the attribute methods. This even works for methods like `format`, because
calling a private method with an explicit receiver will also trigger that hook.
Unfortunately, `read_attribute_for_serialization` is simply an alias to `send`,
which does not respect method visibility. As a result, when serializing a record
with those conflicting attributes, the `method_missing` is not fired, and as a
result the attribute methods are not defined one would expected.
Before d1316bb, this is negated by the fact that calling the `run_callbacks`
method will also trigger a call to `respond_to?`, which is another trigger point
for the class to define its attribute methods. Therefore, when Active Record
tries to run the `after_find` callbacks, it will also define all the attribute
methods thus masking the problem.
* * *
The proper fix for this problem is probably to restrict `read_attribute_for_serialization`
to call public methods only (i.e. alias `read_attribute_for_serialization` to
`public_send` instead of `send`). This however would be quite risky to change
in a patch release and would probably require a full deprecation cycle.
Another approach would be to override `read_attribute_for_serialization` inside
Active Record to force the definition of attribute methods:
def read_attribute_for_serialization(attribute)
self.class.define_attribute_methods
send(attribute)
end
Unfortunately, this is quite likely going to cause a performance degradation.
This patch therefore restores the behaviour from the 4-0-stable branch by
explicitly forcing the class to define its attribute methods in a similar spot
(when records are initialized). This should not cause any extra roundtrips to
the database because the `@columns` should already be cached on the class.
Fixes#15188.
This reverts commit 9a1abedcdeecd9464668695d4f9c1d55a2fd9332, reversing
changes made to c72d6c91a7c0c2dc81cc857a1d6db496e84e0065.
Conflicts:
activerecord/CHANGELOG.md
activerecord/test/models/comment.rb
This change break integration with activerecord-deprecated_finders so
I'm reverting until we find a way to make it work with this gem.
The foreign_key could be `String` and just doing `owners_map[owner_key]`
could return `nil`.
To prevent this bug, we should `to_s` both keys if their types are
different.
Fixes#14734.
This reverts commit e94e6c27af495a2460c811bb506459f1428dec6b.
Conflicts:
activerecord/CHANGELOG.md
The original commit was reverted only to be safe since #14407 were reported.
We don't have any proof we added a regression with the original commit
so reverting it now will give us more problem.
Closes#14407
The `:timestamp` type for columns is unused. All database adapters treat
them as the same database type. All code in `ActiveRecord` which changes
its behavior based on the column's type acts the same in both cases.
However, when the type is passed to code that checks for the `:datetime`
type, but not `:timestamp` (such as XML serialization), the result is
unexpected behavior.
Existing schema definitions will continue to work, and the `timestamp`
type is transparently aliased to `datetime`.
Fix migrations that use enable_extension with table_name_prefix/suffix
Conflicts:
activerecord/CHANGELOG.md
activerecord/lib/active_record/migration.rb
Add support for counter name to be passed as parameter
on `CounterCache::ClassMethods#reset_counters`. This is
to be consistent with the other methods in the module
that all accept counter name.
ActiveRecord::Relation::Merger's filter_binds method does not filter out bind
variables when one of the attribute nodes has a string name, but the other has
a symbol name, even when those names are actually equal.
This can result in there being more bind variables than placeholders in the
generated SQL. This is particularly an issue for PostgreSQL, where this is
treated as an error.
This patch changes the filter_binds method to make it convert both attribute
names to strings before comparing.
In #10410 it was noted that you can no longer create PK's with the
type of bigserial in PostgreSQL in 4.0.0.rc1. This is mostly
because the newer adapter is checking for column type with the
id column instead of just letting it pass through like it did
before.
Side effects:
You may just create a PK column of a type that you really don't
want to be your PK. As far as I can tell this was allowed in 3.2.X
and perhaps an exception should be raised if you try and do
something extremely dumb.
We are reverting these commits, because there are other caveats related
to dirty attributes not being restored when a transaction is rollback.
For instance, nested transactions cannot proper restore the dirty
attributes state after a rollback.
At the moment, the dirty attributes are scoped by the transaction.
When we call `.save` on a record, the dirty attributes will be reset even
if the transaction gets rollback.
[related #13166]
[related #15018]
[related #15016]
[closes#15019]
This reverts commits
* bab48f0a3d53a08bc23ea0887219e8deb963c3d9
* b0fa7cf3ff8432cc2eef3682b34763b7f8c93cc8.
* 73fb39b6faa9de593ae75ad4e3b8e065ea0e53af
* 37c238927fbed059de3f26a90d8923fb377568a5.
* 8d8d4f1560264cd1c74364d67fa0501f6dd2c4fa
Revert "Merge pull request #13166 from bogdan/transaction-magic"
HABTM should fall back to using the normal CollectionAssociation's size calculation if the collection is not cached or loaded.
This addresses both #14913 and #14914 for master.
