Add invisible reCAPTCHA support

demo/rails/.env

@@ -1,3 +1,3 @@
-# these will only work on localhost (registered on mg@z) ... make your own at https://www.google.com/recaptcha
-RECAPTCHA_PUBLIC_KEY=6Le7oRETAAAAAETt105rjswZ15EuVJiF7BxPROkY
-RECAPTCHA_PRIVATE_KEY=6Le7oRETAAAAAL5a8yOmEdmDi3b2pH7mq5iH1bYK
+# reCAPTCHA keys for testing purposes (https://developers.google.com/recaptcha/docs/faq)
+RECAPTCHA_SITE_KEY = 6LeIxAcTAAAAAJcZVRqyHh71UMIEGNQ_MXjiZKhI
+RECAPTCHA_SECRET_KEY = 6LeIxAcTAAAAAGG-vFI1TnRWxMZNFuojJ4WifJWe

demo/rails/app/views/captcha/index.html.erb

@@ -36,11 +36,21 @@
     <%= submit_tag %>
   <% end %>
   <script src="https://www.google.com/recaptcha/api.js?onload=onloadCallback&render=explicit" async defer></script>
-  <%= link_to 'Single ?', '?' %>
+<% elsif params[:invisible] %>
+  <script>
+    function onSubmitCallback() {
+      document.getElementById("invisible-recaptcha-form").submit();
+    }
+  </script>
+  <%= form_tag "/captchas", id: "invisible-recaptcha-form" do %>
+    <%= invisible_recaptcha_tags callback: 'onSubmitCallback' %>
+  <% end %>
 <% else %>
   <%= form_tag "/captchas" do %>
     <%= recaptcha_tags %>
     <%= submit_tag %>
   <% end %>
-  <%= link_to 'Multi ?', '?multi=1' %>
 <% end %>
+<%= link_to 'Single ?', '?' if params[:multi] or params[:invisible] %>
+<%= link_to 'Multi ?', '?multi=1' unless params[:multi] %>
+<%= link_to 'Invisible ?', '?invisible=1' unless params[:invisible] %>

lib/recaptcha/client_helper.rb

@@ -60,5 +60,25 @@ def recaptcha_tags(options = {})
 
       html.respond_to?(:html_safe) ? html.html_safe : html
     end
+
+    # Invisible reCAPTCHA implementation
+    def invisible_recaptcha_tags(options = {})
+      site_key = options[:site_key] || Recaptcha.configuration.site_key!
+      script_url = Recaptcha.configuration.api_server_url
+      data_attributes = [:badge, :theme, :type, :callback, :expired_callback, :size, :tabindex]
+      data_attributes = options.each_with_object({}) do |(k, v), a|
+        a[k] = v if data_attributes.include?(k)
+      end
+      data_attributes[:sitekey] = site_key
+      tag_attributes = data_attributes.map { |k, v| %(data-#{k.to_s.tr('_', '-')}="#{v}") }.join(" ")
+      if id = options[:id]
+        tag_attributes << %( id="#{id}")
+      end
+      class_ = options[:class]
+      html = ""
+      html << %(<script src="#{script_url}" async defer></script>\n) if options.fetch(:script, true)
+      html << %(<button type="submit" class="g-recaptcha #{class_}" #{tag_attributes}>Submit</button>\n)
+      html.respond_to?(:html_safe) ? html.html_safe : html
+    end
   end
 end

test/client_helper_test.rb

@@ -10,7 +10,7 @@
   end
 
   describe "noscript" do
-    it "does not adds noscript tags when noscript is given" do
+    it "does not add noscript tags when noscript is given" do
       recaptcha_tags(noscript: false).wont_include "noscript"
     end
 
@@ -26,7 +26,7 @@
     )
   end
 
-  it "raises withut site key" do
+  it "raises without site key" do
     Recaptcha.configuration.site_key = nil
     assert_raises Recaptcha::RecaptchaError do
       recaptcha_tags
@@ -46,4 +46,31 @@
       "<script"
     )
   end
+
+  describe "invisible recatpcha" do
+    it "uses ssl" do
+      invisible_recaptcha_tags.must_include "\"#{Recaptcha.configuration.api_server_url}\""
+    end
+
+    it "raises without site key" do
+      Recaptcha.configuration.site_key = nil
+      assert_raises Recaptcha::RecaptchaError do
+        invisible_recaptcha_tags
+      end
+    end
+
+    it "includes id as button attribute" do
+      html = invisible_recaptcha_tags(id: 'my_id')
+      html.must_include(
+        " id=\"my_id\""
+      )
+    end
+
+    it "does not include <script> tag when setting script: false" do
+      html = invisible_recaptcha_tags(script: false)
+      html.wont_include(
+        "<script"
+      )
+    end
+  end
 end