views: add table builder abstraction.

app/helpers/application_helper.rb

@@ -197,6 +197,11 @@ module ApplicationHelper
     simple_form_for(:search, method: method, url: url, defaults: defaults, html: html_options, &block)
   end
 
+  def table_for(*options, &block)
+    table = TableBuilder.new(*options, &block)
+    render "table_builder/table", table: table
+  end
+
   def body_attributes(user = CurrentUser.user)
     attributes = %i[id name level level_string theme] + User::BOOLEAN_ATTRIBUTES.map(&:to_sym)
     attributes += User::Roles.map { |role| :"is_#{role}?" }

app/logical/table_builder.rb

@@ -0,0 +1,38 @@
+class TableBuilder
+  class Column
+    attr_reader :attribute, :name, :block, :html_attributes
+
+    def initialize(attribute = nil, name: attribute.to_s.titleize, **html_attributes, &block)
+      @attribute = attribute
+      @html_attributes = html_attributes
+      @name = name
+      @block = block
+    end
+
+    def value(item)
+      if block.present?
+        block.call(item, self)
+        nil
+      else
+        item.send(attribute)
+      end
+    end
+  end
+
+  attr_reader :columns, :html_attributes, :items
+
+  def initialize(items, **html_attributes)
+    @items = items
+    @columns = []
+    @html_attributes = html_attributes
+    yield self if block_given?
+  end
+
+  def column(*options, &block)
+    @columns << Column.new(*options, &block)
+  end
+
+  def row_attributes(item)
+    { id: "#{item.model_name.singular}-#{item.id}", "data-id": item.id }
+  end
+end

app/views/table_builder/_table.html.erb

@@ -0,0 +1,21 @@
+<%= tag.table table.html_attributes do %>
+  <thead>
+    <tr>
+      <% table.columns.each do |column| %>
+        <th><%= column.name %></th>
+      <% end %>
+    </tr>
+  </thead>
+
+  <tbody>
+    <% table.items.each do |item| %>
+      <%= tag.tr table.row_attributes(item) do %>
+        <% table.columns.each do |column| %>
+          <%= tag.td column.html_attributes do %>
+            <%= column.value(item) %>
+          <% end %>
+        <% end %>
+      <% end %>
+    <% end %>
+  </tbody>
+<% end %>