OTHER_EXPLORERS env var

.dialyzer-ignore

@@ -15,7 +15,7 @@ lib/block_scout_web/schema/types.ex:31
 lib/phoenix/router.ex:324
 lib/phoenix/router.ex:402
 lib/block_scout_web/views/layout_view.ex:145: The call 'Elixir.Poison.Parser':'parse!'
-lib/block_scout_web/views/layout_view.ex:231: The call 'Elixir.Poison.Parser':'parse!'
+lib/block_scout_web/views/layout_view.ex:237: The call 'Elixir.Poison.Parser':'parse!'
 lib/block_scout_web/controllers/api/rpc/transaction_controller.ex:21
 lib/block_scout_web/controllers/api/rpc/transaction_controller.ex:22
 lib/explorer/smart_contract/reader.ex:330

CHANGELOG.md

@@ -40,6 +40,7 @@
 - [#3335](https://github.com/poanetwork/blockscout/pull/3335) - MarketCap calculation: check that ETS tables exist before inserting new data or lookup from the table
 
 ### Chore
+- [#3414](https://github.com/poanetwork/blockscout/pull/3414) - Manage lis of other explorers in the footer via env var
 - [#3407](https://github.com/poanetwork/blockscout/pull/3407) - Add EthereumJSONRPC.HTTP.HTTPoison.json_rpc function clause when URL is null
 - [#3405](https://github.com/poanetwork/blockscout/pull/3405) - N/A instead of 0 for market cap if it is not fetched
 - [#3404](https://github.com/poanetwork/blockscout/pull/3404) - DISABLE_KNOWN_TOKENS env var

apps/block_scout_web/config/config.exs

@@ -29,11 +29,7 @@ config :block_scout_web, BlockScoutWeb.Chain,
 
 config :block_scout_web,
   link_to_other_explorers: System.get_env("LINK_TO_OTHER_EXPLORERS") == "true",
-  other_explorers: %{
+  other_explorers: System.get_env("OTHER_EXPLORERS"),
-    "Etherscan" => "https://etherscan.io/",
-    "EtherChain" => "https://www.etherchain.org/",
-    "Bloxy" => "https://bloxy.info/"
-  },
   other_networks: System.get_env("SUPPORTED_CHAINS"),
   webapp_url: System.get_env("WEBAPP_URL"),
   api_url: System.get_env("API_URL"),

apps/block_scout_web/lib/block_scout_web/views/layout_view.ex

@@ -197,12 +197,18 @@ defmodule BlockScoutWeb.LayoutView do
 
   def other_explorers do
     if Application.get_env(:block_scout_web, :link_to_other_explorers) do
-      Application.get_env(:block_scout_web, :other_explorers, [])
+      decode_other_explorers_json(Application.get_env(:block_scout_web, :other_explorers, []))
     else
       []
     end
   end
 
+  defp decode_other_explorers_json(data) do
+    Jason.decode!(~s(#{data}))
+  rescue
+    _ -> []
+  end
+
   def webapp_url(conn) do
     :block_scout_web
     |> Application.get_env(:webapp_url)