Change the api format to a set

app/views/api/event_types/index.jbuilder

@@ -1,5 +1,5 @@
-json.array! @event_types do |event_type|
-  json.extract! event_type, :id
+@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
@@ -11,3 +11,4 @@ json.array! @event_types do |event_type|
       end
     end
   end
+end

app/views/api/events/index.jbuilder

@@ -1,5 +1,5 @@
- json.array! @events do |event|
-  json.id event.id
+@events.each do |event|
+  json.set! event.id do
     json.title event.title
     json.subtitle event.subtitle
     json.length event.length
@@ -10,3 +10,4 @@
     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
+@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

@@ -1,5 +1,5 @@
-json.array! @tracks do |track|
-  json.extract! track, :id
+@tracks.each do |track|
+  json.set! track.id do
     json.name do
       track.translations.each do |translation|
         json.set! translation.locale, translation.name
@@ -11,3 +11,4 @@ json.array! @tracks do |track|
       end
     end
   end
+end