Add has_paper_trail_defaults (#1166)

CHANGELOG.md

@@ -18,6 +18,8 @@ recommendations of [keepachangelog.com](http://keepachangelog.com/).
 
 ### Added
 
+- [#1166](https://github.com/paper-trail-gem/paper_trail/pull/1166) -
+  New global option `has_paper_trail_defaults`, defaults for `has_paper_trail`
 - [#1158](https://github.com/paper-trail-gem/paper_trail/pull/1158) — Add the
   ability to pass options, such as `scope` or `extend:` to the `has_many
   :versions` association macro.

README.md

@@ -268,6 +268,33 @@ A common place to put these settings is in a Rails initializer file
 such as `config/initializers/paper_trail.rb` or in an environment-specific
 configuration file such as `config/environments/test.rb`.
 
+#### 1.e.1 Global
+
+Global configuration options affect all threads.
+
+- association_reify_error_behaviour
+- enabled
+- has_paper_trail_defaults
+- object_changes_adapter
+- serializer
+- version_limit
+
+Syntax example: (options described in detail later)
+
+```ruby
+# config/initializers/paper_trail.rb
+PaperTrail.config.enabled = true
+PaperTrail.config.has_paper_trail_defaults = {
+  on: %i[create update destroy]
+}
+PaperTrail.config.version_limit = 3
+````
+
+These options are intended to be set only once, during app initialization (eg.
+in `config/initializers`). It is unsafe to change them while the app is running.
+In contrast, `PaperTrail.request` has various options that only apply to a
+single HTTP request and thus are safe to use while the app is running.
+
 ## 2. Limiting What is Versioned, and When
 
 ### 2.a. Choosing Lifecycle Events To Monitor
@@ -492,7 +519,7 @@ PaperTrail.request(enabled: false) do
 end
 ```
 
-or, 
+or,
 
 ```ruby
 PaperTrail.request.enabled = false
@@ -543,7 +570,7 @@ It would be better to install your own callback and use
 
 The `widget.paper_trail.without_versioning` method was removed in v10, without
 an exact replacement. To disable versioning, use the [Per Class](#per-class) or
-[Per HTTP Request](#per-http-request) methods. 
+[Per HTTP Request](#per-http-request) methods.
 
 ### 2.e. Limiting the Number of Versions Created
 
@@ -617,8 +644,8 @@ previous and next versions.
 ```ruby
 widget = Widget.find 42
 version = widget.versions[-2]    # assuming widget has several versions
-previous = version.previous
-next = version.next
+previous_version = version.previous
+next_version = version.next
 ```
 
 You can find out which of an item's versions yours is:
@@ -1000,7 +1027,6 @@ end
 Overriding (instead of configuring) the `versions` method is not supported.
 Overriding associations is not recommended in general.
 
-
 ### 5.c. Generators
 
 PaperTrail has one generator, `paper_trail:install`. It writes, but does not

lib/paper_trail/config.rb

@@ -21,7 +21,8 @@ module PaperTrail
       :association_reify_error_behaviour,
       :object_changes_adapter,
       :serializer,
-      :version_limit
+      :version_limit,
+      :has_paper_trail_defaults
     )
 
     def initialize
@@ -31,6 +32,7 @@ module PaperTrail
 
       # Variables which affect all threads, whose access is *not* synchronized.
       @serializer = PaperTrail::Serializers::YAML
+      @has_paper_trail_defaults = {}
     end
 
     # Indicates whether PaperTrail is on or off. Default: true.

lib/paper_trail/has_paper_trail.rb

@@ -23,18 +23,18 @@ module PaperTrail
       # Options:
       #
       # - :on - The events to track (optional; defaults to all of them). Set
-      #   to an array of `:create`, `:update`, `:destroy` as desired.
+      #   to an array of `:create`, `:update`, `:destroy` and `:touch` as desired.
       # - :class_name (deprecated) - The name of a custom Version class that
       #   includes `PaperTrail::VersionConcern`.
       # - :ignore - An array of attributes for which a new `Version` will not be
-      #   created if only they change. It can also aceept a Hash as an
+      #   created if only they change. It can also accept a Hash as an
       #   argument where the key is the attribute to ignore (a `String` or
       #   `Symbol`), which will only be ignored if the value is a `Proc` which
       #   returns truthily.
       # - :if, :unless - Procs that allow to specify conditions when to save
       #   versions for an object.
       # - :only - Inverse of `ignore`. A new `Version` will be created only
-      #   for these attributes if supplied it can also aceept a Hash as an
+      #   for these attributes if supplied it can also accept a Hash as an
       #   argument where the key is the attribute to track (a `String` or
       #   `Symbol`), which will only be counted if the value is a `Proc` which
       #   returns truthily.
@@ -57,9 +57,15 @@ module PaperTrail
       # Plugins like the experimental `paper_trail-association_tracking` gem
       # may accept additional options.
       #
+      # You can define a default set of options via the configurable
+      # `PaperTrail.config.has_paper_trail_defaults` hash in your applications
+      # initializer. The hash can contain any of the following options and will
+      # provide an overridable default for all models.
+      #
       # @api public
       def has_paper_trail(options = {})
-        paper_trail.setup(options)
+        defaults = PaperTrail.config.has_paper_trail_defaults
+        paper_trail.setup(defaults.merge(options))
       end
 
       # @api public