tipping: only show tipping sites with paypal/btc input

app/browse.rb

@@ -85,6 +85,7 @@ def browse_sites_dataset
       site_dataset.order!(:site_updated_at.desc, :views.desc)
     when 'tipping_enabled'
       site_dataset.where! tipping_enabled: true
+      site_dataset.where!("(tipping_paypal is not null and tipping_paypal != '') or (tipping_bitcoin is not null and tipping_bitcoin != '')")
       site_dataset = site_dataset.association_left_join :follows
       site_dataset.select_all! :sites
       site_dataset.select_append! Sequel.lit("count(follows.site_id) AS follow_count")

models/site.rb

@@ -1356,6 +1356,10 @@ class Site < Sequel::Model
     !site_files_dataset.where(path: /^\/?index.html$/).where(sha1_hash: EMPTY_FILE_HASH).first.nil?
   end
 
+  def tipping_enabled?
+    tipping_enabled && (!tipping_paypal.blank? || !tipping_bitcoin.blank?)
+  end
+
   def classify(path)
     return nil unless classification_allowed? path
     #$classifier.classify process_for_classification(path)

views/site.erb

@@ -56,7 +56,7 @@
 
         <a href="#" id="shareButton" class="btn-Action" data-container="body" data-toggle="popover" data-placement="bottom" data-content='<%== erb :'_share', layout: false, locals: {site: site} %>'><i class="fa fa-share-alt"></i> <span>Share</span></a>
 
-        <% if site.tipping_enabled && (!site.tipping_paypal.blank? || !site.tipping_bitcoin.blank?) %>
+        <% if site.tipping_enabled? %>
           <a href="#" id="tipButton" class="btn-Action" data-container="body" data-toggle="popover" data-placement="bottom" data-content='<%== erb :'site/_tip', layout: false, locals: {site: site} %>'><i class="fa fa-usd"></i> <span>Send a Tip</span></a>
         <% end %>
       </div>