Add text_field component to solidus_admin

This component is used to render a text field in a form. It leverages
the `type` attribute to also render different input fields, although we
might want to specialize in the future.

It comes in three sizes: small, medium and large. It also supports
rendering a label and a hint, as well as field error messages.

It needs to be rendered in the context of a block yielded by one of
Rails' form helpers, such as `form_for` or `form_with`. This is to
leverage the automatic inferrence of the `name`, `id` and `for`
attributes, therefore avoiding boilerplate. When the given form builder
is bound to a model instance, the error messages will be automatically
extracted. Otherwise, an explicit errors hash needs to be passed.

Ref. #5329

admin/app/components/solidus_admin/ui/forms/text_field/component.rb

@@ -0,0 +1,155 @@
+# frozen_string_literal: true
+
+class SolidusAdmin::UI::Forms::TextField::Component < SolidusAdmin::BaseComponent
+  SIZES = {
+    s: 'leading-4 body-small',
+    m: 'leading-6 body-small',
+    l: 'leading-9 body-text'
+  }.freeze
+
+  TYPES = {
+    color: :color_field,
+    date: :date_field,
+    datetime: :datetime_field,
+    email: :email_field,
+    month: :month_field,
+    number: :number_field,
+    password: :password_field,
+    phone: :phone_field,
+    range: :range_field,
+    search: :search_field,
+    text: :text_field,
+    time: :time_field,
+    url: :url_field,
+    week: :week_field
+  }.freeze
+
+  # @param field [Symbol] the name of the field. Usually a model attribute.
+  # @param form [ActionView::Helpers::FormBuilder] the form builder instance.
+  # @param type [Symbol] the type of the field. Defaults to `:text`.
+  # @param size [Symbol] the size of the field: `:s`, `:m` or `:l`.
+  # @param hint [String, null] helper text to display below the field.
+  # @param errors [Hash, nil] a Hash of errors for the field. If `nil` and the
+  #   form is bound to a model instance, the component will automatically fetch
+  #   the errors from the model.
+  # @param attributes [Hash] additional HTML attributes to add to the field.
+  # @raise [ArgumentError] when the form builder is not bound to a model
+  #  instance and no `errors` Hash is passed to the component.
+  def initialize(field:, form:, type: :text, size: :m, hint: nil, errors: nil, **attributes)
+    @field = field
+    @form = form
+    @type = type
+    @size = size
+    @hint = hint
+    @type = type
+    @attributes = attributes
+    @errors = errors || @form.object&.errors || raise(ArgumentError, <<~MSG
+      When the form builder is not bound to a model instance, you must pass an
+      errors Hash (`field_name: [errors]`) to the component.
+    MSG
+    )
+  end
+
+  def call
+    tag.div do
+      label_tag + field_tag + hint_tag + error_tag
+    end
+  end
+
+  def label_tag
+    @form.label(@field, class: "block mb-0.5 body-tiny-bold")
+  end
+
+  def field_tag
+    @form.send(
+      field_helper,
+      @field,
+      class: "
+        peer
+        block px-3 py-1.5 w-full
+        text-black text-black
+        bg-white border border-gray-300 rounded-sm
+        hover:border-gray-500
+        placeholder:text-gray-400
+        focus:border-gray-500 focus:shadow-[0_0_0_2px_#bbb] focus-visible:outline-none
+        disabled:bg-gray-50 disabled:text-gray-300
+        #{field_size_classes}
+        #{field_error_classes}
+        #{@attributes[:class]}
+      ",
+      **field_aria_describedby_attribute,
+      **field_error_attributes,
+      **@attributes.except(:class)
+    )
+  end
+
+  def field_helper
+    TYPES.fetch(@type)
+  end
+
+  def field_size_classes
+    SIZES.fetch(@size)
+  end
+
+  def field_error_classes
+    return "" unless errors?
+
+    "border-red-400 text-red-400"
+  end
+
+  def field_aria_describedby_attribute
+    return {} unless @hint || errors?
+
+    {
+      "aria-describedby": "#{hint_id if @hint} #{error_id if errors?}"
+    }
+  end
+
+  def field_error_attributes
+    return {} unless errors?
+
+    {
+      "aria-invalid": true
+    }
+  end
+
+  def hint_tag
+    return unless @hint
+
+    tag.p(id: hint_id, class: "mt-2 body-tiny text-gray-500 peer-disabled:text-gray-300 #{hint_error_classes}") do
+      @hint
+    end
+  end
+
+  def hint_error_classes
+    return {} unless errors?
+
+    "text-red-400"
+  end
+
+  def hint_id
+    "#{id_prefix}_hint"
+  end
+
+  def error_tag
+    return unless errors?
+
+    tag.p(id: error_id, class: "mt-2 body-tiny text-red-400") do
+      @errors[@field].map do |error|
+        tag.span(class: "block") { error }
+      end.reduce(&:+)
+    end
+  end
+
+  def errors?
+    @errors[@field].present?
+  end
+
+  def error_id
+    "#{id_prefix}_error"
+  end
+
+  def id_prefix
+    "#{@form.object_name}_#{@field}"
+  end
+end

admin/spec/components/previews/solidus_admin/ui/forms/text_field/component_preview.rb

@@ -0,0 +1,101 @@
+# frozen_string_literal: true
+
+# @component "ui/forms/text_field"
+class SolidusAdmin::UI::Forms::TextField::ComponentPreview < ViewComponent::Preview
+  include SolidusAdmin::Preview
+
+  # The text field component is used to render a text field in a form.
+  #
+  # It must be used within the block context yielded in the [`form_with`
+  # ](https://api.rubyonrails.org/v5.1/classes/ActionView/Helpers/FormHelper.html#method-i-form_with)
+  # or
+  # [`form_for`](https://api.rubyonrails.org/v5.1/classes/ActionView/Helpers/FormHelper.html#method-i-form_for)
+  # helpers.
+  #
+  # When the form builder is not bound to a model instance, you must pass an
+  # errors Hash to the component. For example:
+  #
+  # ```erb
+  # <%= form_with(url: search_path, method: :get) do |form| %>
+  #  <%= render components('ui/forms/text_field').new(
+  #    form: form,
+  #    field: :q,
+  #    errors: params[:q].present? ? {} : {
+  #      q: ["can't be blank"]
+  #    }
+  #  ) %>
+  #  <%= form.submit "Search" %>
+  # <% end %>
+  # ```
+  #
+  # When the form builder is bound to a model instance, the component will
+  # automatically fetch the errors from the model.
+  #
+  # ```erb
+  # <%= form_with(model: @user) do |form| %>
+  #   <%= render components('ui/forms/text_field').new(
+  #     form: form,
+  #     field: :name
+  #   ) %>
+  #   <%= form.submit "Save" %>
+  # <% end %>
+  def overview
+    render_with_template(
+      locals: {
+        sizes: current_component::SIZES.keys,
+        variants: {
+          "empty" => {
+            value: nil, disabled: false, hint: nil, errors: {}
+          },
+          "filled" => {
+            value: "Alice", disabled: false, hint: nil, errors: {}
+          },
+          "with_hint" => {
+            value: "Alice", disabled: false, hint: "Your name", errors: {}
+          },
+          "empty_with_error" => {
+            value: nil, disabled: false, hint: nil, errors: { "empty_with_error" => ["can't be blank"] }
+          },
+          "filled_with_error" => {
+            value: "Alice", disabled: false, hint: nil, errors: { "filled_with_error" => ["is invalid"] }
+          },
+          "with_hint_and_error" => {
+            value: "Alice", disabled: false, hint: "Your name", errors: { "with_hint_and_error" => ["is invalid"] }
+          },
+          "empty_disabled" => {
+            value: nil, disabled: true, hint: nil, errors: {}
+          },
+          "filled_disabled" => {
+            value: "Alice", disabled: true, hint: nil, errors: {}
+          },
+          "with_hint_disabled" => {
+            value: "Alice", disabled: true, hint: "Your name", errors: {}
+          }
+        }
+      }
+    )
+  end
+
+  # @param size select { choices: [s, m, l] }
+  # @param type select { choices: [color, date, datetime, email, month, number, password, phone, range, search, text, time, url, week] }
+  # @param label text
+  # @param value text
+  # @param hint text
+  # @param errors text (comma separated)
+  # @param placeholder text
+  # @param disabled toggle
+  def playground(size: :m, type: :text, label: "Name", value: nil, hint: nil, errors: "", placeholder: "Placeholder", disabled: false)
+    render_with_template(
+      locals: {
+        size: size.to_sym,
+        type: type.to_sym,
+        field: label,
+        value: value,
+        hint: hint,
+        errors: { label.dasherize => (errors.blank? ? [] : errors.split(",").map(&:strip)) },
+        placeholder: placeholder,
+        disabled: disabled
+      }
+    )
+  end
+end

admin/spec/components/previews/solidus_admin/ui/forms/text_field/component_preview/overview.html.erb

@@ -0,0 +1,34 @@
+<%= form_with(url: "#", method: :get) do |form| %>
+  <table>
+    <thead>
+      <tr>
+        <% sizes.each do |size| %>
+          <td class="px-3 py-1 text-gray-500 text-center body-text"><%= size.to_s.humanize %></td>
+        <% end %>
+      </tr>
+    </thead>
+    <tbody>
+      <%
+        variants.each_pair do |name, definition| %>
+          <tr>
+            <% sizes.each do |size| %>
+              <td class="px-3 py-1">
+                <%=
+                  render current_component.new(
+                    form: form,
+                    field: name,
+                    size: size,
+                    errors: definition[:errors],
+                    hint: definition[:hint],
+                    disabled: definition[:disabled],
+                    placeholder: "Placeholder",
+                    value: definition[:value]
+                  )
+                %>
+              </td>
+            <% end %>
+          </tr>
+      <% end %>
+    </tbody>
+  </table>
+<% end %>

admin/spec/components/previews/solidus_admin/ui/forms/text_field/component_preview/playground.html.erb

@@ -0,0 +1,16 @@
+<%= form_with(url: "#", method: :get) do |form| %>
+  <%=
+    render current_component.new(
+      form: form,
+      size: size,
+      type: type,
+      field: field,
+      value: value,
+      hint: hint,
+      errors: errors,
+      placeholder: placeholder,
+      disabled: disabled,
+      class: "w-56"
+    )
+  %>
+<% end %>

admin/spec/components/solidus_admin/ui/forms/text_field/component_spec.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe SolidusAdmin::UI::Forms::TextField::Component, type: :component do
+  it "renders the overview preview" do
+    render_preview(:overview)
+    render_preview(:playground)
+  end
+
+  describe "#initialize" do
+    it "uses given errors when form is bound to a model" do
+      form = double("form", object: double("model", errors: {}))
+
+      component = described_class.new(form: form, field: :name, errors: { name: ["can't be blank"] })
+
+      expect(component.errors?).to be(true)
+    end
+
+    it "uses model errors when form is bound to a model and they are not given" do
+      form = double("form", object: double("model", errors: { name: ["can't be blank"] }))
+
+      component = described_class.new(form: form, field: :name)
+
+      expect(component.errors?).to be(true)
+    end
+
+    it "uses given errors when form is not bound to a model" do
+      form = double("form", object: nil)
+
+      component = described_class.new(form: form, field: :name, errors: { name: ["can't be blank"] })
+
+      expect(component.errors?).to be(true)
+    end
+
+    it "raises an error when form is not bound to a model and errors are not given" do
+      form = double("form", object: nil)
+
+      expect { described_class.new(form: form, field: :name) }.to raise_error(ArgumentError)
+    end
+  end
+end