Change the api format to a set

app/views/api/event_types/index.jbuilder

@@ -1,13 +1,14 @@
-json.array! @event_types do |event_type|
-  json.extract! event_type, :id
-  json.name do
-    event_type.translations.each do |translation|
-      json.set! translation.locale, translation.name
+@event_types.each do |event_type|
+  json.set! event_type.id do
+    json.name do
+      event_type.translations.each do |translation|
+        json.set! translation.locale, translation.name
+      end
     end
-  end
-  json.description do
-    event_type.translations.each do |translation|
-      json.set! translation.locale, translation.description
+    json.description do
+      event_type.translations.each do |translation|
+        json.set! translation.locale, translation.description
+      end
     end
   end
 end

app/views/api/events/index.jbuilder

@@ -1,12 +1,13 @@
- json.array! @events do |event|
-  json.id event.id
-  json.title event.title
-  json.subtitle event.subtitle
-  json.length event.length
-  json.language event.language
-  json.abstract event.abstract
-  json.description event.description
-  json.event_type_id event.event_type_id
-  json.track_id event.track_id
-  json.participant_user_ids event.participations.map(&:participant_id)
+@events.each do |event|
+  json.set! event.id do
+    json.title event.title
+    json.subtitle event.subtitle
+    json.length event.length
+    json.language event.language
+    json.abstract event.abstract
+    json.description event.description
+    json.event_type_id event.event_type_id
+    json.track_id event.track_id
+    json.participant_user_ids event.participations.map(&:participant_id)
+  end
 end

app/views/api/halls/index.jbuilder

@@ -1 +1,5 @@
-json.array! @halls, :id, :name
+@halls.each do |hall|
+  json.set! hall.id do
+    json.extract! hall, :name
+  end
+end

app/views/api/slots/index.jbuilder

@@ -1 +1,5 @@
-json.array! @slots, :hall_id, :event_id, :starts_at, :ends_at
+@slots.each do |slot|
+  json.set! slot.id do
+    json.extract! slot, :hall_id, :event_id, :starts_at, :ends_at
+  end
+end

app/views/api/speakers/index.jbuilder

@@ -1,4 +1,6 @@
-json.array! @speakers do |speaker|
-  json.extract! speaker, :user_id, :twitter, :github, :biography, :public_email, :organisation, :last_name, :first_name
-  json.picture speaker.picture.serializable_hash
+@speakers.each do |speaker|
+  json.set! speaker.id do
+    json.extract! speaker, :twitter, :github, :biography, :public_email, :organisation, :last_name, :first_name
+    json.picture speaker.picture.serializable_hash
+  end
 end

app/views/api/tracks/index.jbuilder

@@ -1,13 +1,14 @@
-json.array! @tracks do |track|
-  json.extract! track, :id
-  json.name do
-    track.translations.each do |translation|
-      json.set! translation.locale, translation.name
+@tracks.each do |track|
+  json.set! track.id do
+    json.name do
+      track.translations.each do |translation|
+        json.set! translation.locale, translation.name
+      end
     end
-  end
-  json.description do
-    track.translations.each do |translation|
-      json.set! translation.locale, translation.description
+    json.description do
+      track.translations.each do |translation|
+        json.set! translation.locale, translation.description
+      end
     end
   end
 end