Add gem configuration, with base component customization (#160)

* Add gem configuration, with base component customization

* Add documentation for parent_component configuration

* Remove unnecessary relative require, Zeitwerk autoloads Configuration constant

* Remove unescessary implementation examples in configuration README example

* Update parent_component configuration to be easier to grok

Co-authored-by: Hans Lemuet <Spone@users.noreply.github.com>

* Add changelog entry for #160

---------

Co-authored-by: Hans Lemuet <Spone@users.noreply.github.com>

CHANGELOG.md

@@ -6,6 +6,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Added parent_component configuration for field components (#160)
+
 ## [0.2.6] - 2023-10-11
 ### Added
 - Support for Rails 7.1 (#151)

README.md

@@ -194,6 +194,12 @@ You can use the same approach to inject options, wrap the input in a `<div>`, et
 
 We'll add more use cases to the documentation soon.
 
+### Configuration
+
+| Attribute          | Purpose                                         | Default               |
+| ------------------ | ----------------------------------------------- | --------------------- |
+| `parent_component` (string) | Parent class for all `ViewComponent::Form` components | `"ViewComponent::Base"` |
+
 ### Building your own components
 
 When building your own ViewComponents for using in forms, it's recommended to inherit from `ViewComponent::Form::FieldComponent`, so you get access to the following helpers:
@@ -339,6 +345,22 @@ def length_validator
 end
 ```
 
+### Setting up your own base component class
+
+1. Setup some base component from which the form components will inherit from
+```rb
+class ApplicationFormComponent < ViewComponent::Base
+end
+```
+2. Configure the parent component class
+```rb
+# config/initializers/vcf.rb
+
+ViewComponent::Form.configure do |config|
+  config.parent_component = 'ApplicationFormComponent'
+end
+```
+
 ### Using your form components without a backing model
 
 If you want to ensure that your fields display consistently across your app, you'll need to lean on Rails' own helpers. You may be used to using form tag helpers such as `text_field_tag` to generate tags, or even writing out plain HTML tags. These can't be integrated with a form builder, so they won't offer you the benefits of this gem.

app/components/view_component/form/base_component.rb

@@ -2,7 +2,7 @@
 
 module ViewComponent
   module Form
-    class BaseComponent < ViewComponent::Base
+    class BaseComponent < ViewComponent::Form.configuration.parent_component.constantize
       class << self
         attr_accessor :default_options
       end

lib/view_component/form.rb

@@ -5,6 +5,15 @@
 
 module ViewComponent
   module Form
+    class << self
+      def configuration
+        @configuration ||= Configuration.new
+      end
+
+      def configure
+        yield configuration
+      end
+    end
   end
 end
 

lib/view_component/form/configuration.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module ViewComponent
+  module Form
+    class Configuration
+      attr_accessor :parent_component
+
+      def initialize
+        @parent_component = "ViewComponent::Base"
+      end
+    end
+  end
+end

spec/internal/app/components/application_form_component.rb

@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+class ApplicationFormComponent < ViewComponent::Base
+end

spec/internal/config/initializers/view_component_form.rb

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+ViewComponent::Form.configure do |config|
+  config.parent_component = "ApplicationFormComponent"
+end

spec/view_component/form/base_component_spec.rb

@@ -46,4 +46,12 @@ def name
       it { expect(component.object_errors?).to be(false) }
     end
   end
+
+  describe "parent_component" do
+    subject { described_class }
+
+    context "without configured parent_component" do
+      it { is_expected.to be < ViewComponent::Base }
+    end
+  end
 end

spec/view_component/form/builder_spec.rb

@@ -192,4 +192,12 @@
       it { expect(builder.send(:validation_context)).to eq(:create) }
     end
   end
+
+  describe "base component parent" do
+    subject(:field) { described_class.new(object_name, object, template, options).send(:component_klass, :text_field) }
+
+    it "is configured via initializer" do
+      expect(field.ancestors).to include(ApplicationFormComponent)
+    end
+  end
 end

spec/view_component/form/configuration_spec.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+RSpec.describe ViewComponent::Form::Configuration do
+  subject(:configuration) { described_class.new }
+
+  describe "defaults" do
+    it do
+      expect(configuration).to have_attributes(parent_component: "ViewComponent::Base")
+    end
+  end
+end

spec/view_component/form_spec.rb

@@ -5,6 +5,10 @@
     expect(ViewComponent::Form::VERSION).not_to be_nil
   end
 
+  it "is configurable" do
+    expect { |block| described_class.configure(&block) }.to yield_with_args(ViewComponent::Form::Configuration)
+  end
+
   if ENV.fetch("VIEW_COMPONENT_FORM_USE_ACTIONTEXT", "false") == "true"
     it "loads ActionText" do
       expect(defined?(ActionView::Helpers::Tags::ActionText)).to eq("constant")