Require ‘gocode’ via TextMate 2’s required command system

This leads to a better user experience and allow the user to set TM_GOCODE instead of updating PATH.

Commands/Complete.tmCommand

@@ -12,8 +12,6 @@ require ENV['TM_SUPPORT_PATH'] + "/lib/tm/require_cmd.rb"
 require ENV['TM_SUPPORT_PATH'] + "/lib/tm/htmloutput.rb"
 require ENV['TM_SUPPORT_PATH'] + "/lib/web_preview"
 
-TextMate.require_cmd("gocode")
-
 # current document
 document = []
 File.open(ENV['TM_FILEPATH'], "r+") do |file|
@@ -22,7 +20,7 @@ end
 
 # byte offset of cursor position from the beginning of file
 cursor = document[ 0, ENV['TM_LINE_NUMBER'].to_i - 1].join().length + ENV['TM_LINE_INDEX'].to_i
-output = `gocode -f=csv -in=#{e_sh ENV['TM_FILEPATH']} autocomplete #{cursor}`
+output = `$TM_GOCODE -f=csv -in=#{e_sh ENV['TM_FILEPATH']} autocomplete #{cursor}`
 
 # quit if no completions found
 TextMate.exit_show_tool_tip("No completions found.") if output.length == 0
@@ -129,6 +127,17 @@ end</string>
 	<string>text</string>
 	<key>outputLocation</key>
 	<string>atCaret</string>
+	<key>requiredCommands</key>
+	<array>
+		<dict>
+			<key>command</key>
+			<string>gocode</string>
+			<key>moreInfoURL</key>
+			<string>https://github.com/nsf/gocode</string>
+			<key>variable</key>
+			<string>TM_GOCODE</string>
+		</dict>
+	</array>
 	<key>scope</key>
 	<string>source.go</string>
 	<key>uuid</key>