Allow number of trending hashtags to be customizable (#1884)

.env.production.sample

@@ -279,6 +279,10 @@ MAX_POLL_OPTION_CHARS=100
 # Only relevant when elasticsearch is installed
 # MAX_SEARCH_RESULTS=20
 
+# Maximum hashtags to display
+# Customize the number of hashtags shown in 'Explore'
+# MAX_TRENDING_TAGS=10
+
 # Maximum custom emoji file sizes
 # If undefined or smaller than MAX_EMOJI_SIZE, the value
 # of MAX_EMOJI_SIZE will be used for MAX_REMOTE_EMOJI_SIZE

app/controllers/api/v1/trends/tags_controller.rb

@@ -5,7 +5,7 @@ class Api::V1::Trends::TagsController < Api::BaseController
 
   after_action :insert_pagination_headers
 
-  DEFAULT_TAGS_LIMIT = 10
+  DEFAULT_TAGS_LIMIT = (ENV['MAX_TRENDING_TAGS'] || 10).to_i
 
   def index
     render json: @tags, each_serializer: REST::TagSerializer, relationships: TagRelationshipsPresenter.new(@tags, current_user&.account_id)