Also make it actually work.

It slows down all read_attribute accesses to map 'id' to whatever the PK
actually is, inside read_attribute. So instead make sure the necessary
methods are defined and that they redirect wherever they need to go.

This is good because it reduces duplication.

This makes me happy!

Define singleton methods on the attributes module instead. This reduces
method pollution on the actual model classes. It also seems to make
something faster, I am unsure why! O_o

This reverts commit ee2be435.

If we don't have a primary key when we ask for it, it's better to fail
fast. Fixes GH #2307.

Return nil from read_attribute(:foo) if 'foo' is not present in the @attributes hash, but the _foo method has been defined. This brings the behaviour into line with the 3-0-stable branch and the master branch before 93641ed6 (there were previously no assertions about this which is why the change slipped through). Note that actually calling the 'foo' method will still raise an error if the attribute is not present.

Undo performances regressions I introduced in bbe0a507 and add test for an edge case. Add comments to explain the intent of the code.

Remove unnecessary code from define_read_method and add assertion to make sure the underscored version is actually generated

Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

Cheaper attribute reads and respond_to?. Add underscore-prefixed method aliased to the attribute name so it can be overridden but still called internally.

This reverts commit f936a1f1.

Conflicts:

	activerecord/lib/active_record.rb
	activerecord/lib/active_record/base.rb

Revert "Fixed: #without_typecast should only disable typecasting on the duplicated attributes" [#3387 state:open]

This reverts commit 28319964.

Reason :

  It's not generating attribute methods properly, making object.column 5x slower.

Signed-off-by: NJoshua Peek <josh@joshpeek.com>

Modified ActiveRecord::AttributeMethods to allow classes to specify attribute method prefixes and/or suffixes. Previously only suffixes were allowed.
Signed-off-by: NJoshua Peek <josh@joshpeek.com>