add option submits_with to button

README.md

@@ -1068,6 +1068,21 @@ will be rendered as
 
 (some unimportant HTML attributes have been removed for simplicity)
 
+### Turbo submits with
+There is a turbo attribute [(data-turbo-submits-with)](https://turbo.hotwired.dev/reference/attributes) that replaces the content of a submit button while the request is processing. This only works on `f.button` or `f.primary` not on `f.submit` and forces `render_as_button: true` on `f.primary` since `<submit>` tags only allow text content.
+
+You can have `bootstrap_form` put up a default bootstrap spinner while the request is processing with the following:
+```erb
+<%= f.button "Save", data: { turbo_submits_with: f.spinner } %>
+
+<%= f.button "Save", data: { turbo_submits_with: "<span>Loading...</span>" } %>
+```
+
+```html
+<button class="btn btn-secondary" data-turbo-submits-with="<span>Loading...</span>" name="button" type="submit">Save</button>
+```
+
+
 ## Rich Text Areas AKA Trix Editor
 
 ![Example 38](demo/doc/screenshots/bootstrap/readme/38_example.png "Example 38")

lib/bootstrap_form/helpers/bootstrap.rb

@@ -96,6 +96,14 @@ def static_class
         "form-control-plaintext"
       end
 
+      def spinner
+        tag.div(class: "text-center") do
+          tag.div(class: "spinner-border spinner-border-sm", role: "status") do
+            tag.span("Loading...", class: "visually-hidden")
+          end
+        end
+      end
+
       private
 
       def attach_input(options, key)

lib/bootstrap_form/inputs/submit.rb

@@ -16,7 +16,7 @@ def submit(value=nil, options={})
       def primary(value=nil, options={}, &block)
         value = setup_css_class "btn btn-primary", value, options
 
-        if options[:render_as_button] || block
+        if options[:render_as_button] || options.dig(:data, :turbo_submits_with) || block
           options.except! :render_as_button
           button(value, options, &block)
         else

test/bootstrap_other_components_test.rb

@@ -152,6 +152,22 @@ class BootstrapOtherComponentsTest < ActionView::TestCase
                            @builder.button("<span>I'm HTML!</span> in a button!".html_safe, extra_class: "test-button")
   end
 
+  test "regular button has turbo-submits-with default spinner" do
+    expected = <<~HTML
+      <button class="btn btn-secondary" data-turbo-submits-with='&lt;div class="text-center"&gt;&lt;div class="spinner-border spinner-border-sm" role="status"&gt;&lt;span class="visually-hidden"&gt;Loading...&lt;/span&gt;&lt;/div&gt;&lt;/div&gt;' name="button" type="submit">Submit with Spinner</button>
+    HTML
+    assert_equivalent_html expected,
+                           @builder.button("Submit with Spinner", data: { turbo_submits_with: @builder.spinner })
+  end
+
+  test "regular button has turbo-submits-with custom HTML" do
+    expected = <<~HTML
+      <button class="btn btn-secondary" data-turbo-submits-with="<span>Loading...</span>" name="button" type="submit">Submit with Spinner</button>
+    HTML
+    assert_equivalent_html expected,
+                           @builder.button("Submit with Spinner", data: { turbo_submits_with: "<span>Loading...</span>" })
+  end
+
   test "submit button defaults to rails action name" do
     expected = '<input class="btn btn-secondary" name="commit" type="submit" value="Create User" />'
     assert_equivalent_html expected, @builder.submit