Server Greeting Refactor (#1034)

Refactors the Server Greeting datum to do majority of the processing clientside. No longer will we be holding massive spans of text in memory, and looking over them for shits and giggles.

code/datums/server_greeting.dm

@@ -14,6 +14,8 @@
 #define OUTDATED_MEMO 2
 #define OUTDATED_NOTE 4
 
+#define JS_SANITIZE(msg) list2params(list(json_encode(msg)))
+
 /datum/server_greeting
 	// Hashes to figure out if we need to display the greeting message.
 	// These correspond to motd_hash and memo_hash on /datum/preferences for each client.
@@ -21,24 +23,19 @@
 	var/memo_hash = ""
 
 	// The stored strings of general subcomponents.
-	var/motd = ""
-	var/memo_list[] = list()
-	var/memo = ""
+	var/motd = "<center>No new announcements to showcase.</center>"
 
-	var/raw_data_user = ""
-	var/raw_data_staff = ""
-	// The near-final string to be displayed.
-	// Only one placeholder remains: <!--notifications-->.
-	var/user_data = ""
-	var/staff_data = ""
+	var/memo_list[] = list()
+	var/memo = "<center>No memos have been posted.</center>"
+
+	// Cached outdated information.
+	var/list/client_cache = list()
 
 /datum/server_greeting/New()
 	..()
 
 	load_from_file()
 
-	prepare_data()
-
 /*
  * Populates variables from save file, and loads the raw HTML data.
  * Needs to be called at least once for successful initialization.
@@ -52,51 +49,33 @@
 		if (F["memo"])
 			F["memo"] >> memo_list
 
-	raw_data_staff = file2text('html/templates/welcome_screen.html')
-
-	// This is a lazy way, but it disables the user from being able to see the memo button.
-	var/staff_button = "<li role=\"presentation\" id=\"memo-tab\"><a href=\"#memo\" aria-controls=\"memo\" role=\"tab\" data-toggle=\"tab\">Staff Memos</a></li>"
-	raw_data_user = replacetextEx(raw_data_staff, staff_button, "")
+	update_data()
 
 /*
- * Generates hashes, placeholders, and reparses var/memo.
- * Then updates staff_data and user_data with the new contents.
- * To be called after load_from_file or update_value.
+ * A helper to regenerate the hashes for all data fields.
+ * As well as to reparse the staff memo list.
+ * Separated for the sake of avoiding the duplication of code.
  */
-/datum/server_greeting/proc/prepare_data()
-	if (!motd)
-		motd = "<center>No new announcements to showcase.</center>"
-		motd_hash = ""
-	else
+/datum/server_greeting/proc/update_data()
+	if (motd)
 		motd_hash = md5(motd)
-
-	memo = ""
+	else
+		motd = initial(motd)
+		motd_hash = ""
 
 	if (memo_list.len)
+		memo = ""
 		for (var/ckey in memo_list)
-			var/data = {"
-			<p><b>[ckey]</b> wrote on [memo_list[ckey]["date"]]:<br>
-			[memo_list[ckey]["content"]]</p>
-			"}
+			var/data = {"<p><b>[ckey]</b> wrote on [memo_list[ckey]["date"]]:<br>
+			[memo_list[ckey]["content"]]</p>"}
 
 			memo += data
 
 		memo_hash = md5(memo)
 	else
-		memo = "<center>No memos have been posted.</center>"
+		memo = initial(memo)
 		memo_hash = ""
 
-	var/html_one = raw_data_staff
-	html_one = replacetextEx(html_one, "<!--motd-->", motd)
-	html_one = replacetextEx(html_one, "<!--memo-->", memo)
-	staff_data = html_one
-
-	var/html_two = raw_data_user
-	html_two = replacetextEx(html_two, "<!--motd-->", motd)
-	user_data = html_two
-
-	return
-
 /*
  * Helper to update the MoTD or memo contents.
  * Args:
@@ -113,7 +92,6 @@
 	switch (change)
 		if ("motd")
 			motd = new_value
-			motd_hash = md5(new_value)
 
 		if ("memo_write")
 			memo_list[new_value[1]] = list("date" = time2text(world.realtime, "DD-MMM-YYYY"), "content" = new_value[2])
@@ -131,7 +109,7 @@
 	F["motd"] << motd
 	F["memo"] << memo_list
 
-	prepare_data()
+	update_data()
 
 	return 1
 
@@ -142,10 +120,13 @@
  * Returns:
  * - int
  */
-/datum/server_greeting/proc/find_outdated_info(var/client/user)
+/datum/server_greeting/proc/find_outdated_info(var/client/user, var/force_eval = 0)
 	if (!user || !user.prefs)
 		return 0
 
+	if (!force_eval && !isnull(client_cache[user]))
+		return client_cache[user]
+
 	var/outdated_info = 0
 
 	if (motd_hash && user.prefs.motd_hash != motd_hash)
@@ -157,53 +138,88 @@
 	if (user.prefs.notifications.len)
 		outdated_info |= OUTDATED_NOTE
 
+	client_cache[user] = outdated_info
+
 	return outdated_info
 
 /*
- * Composes the final message and displays it to the user.
- * Also clears the user's notifications, should he have any.
+ * A proc used to open the server greeting window for a user.
+ * Args:
+ * - var/user client
+ * - var/outdated_info int
  */
-/datum/server_greeting/proc/display_to_client(var/client/user, var/outdated_info = 0)
+/datum/server_greeting/proc/display_to_client(var/client/user)
 	if (!user)
 		return
 
-	var/notifications = "<div class=\"row\"><div class=\"alert alert-info\">You do not have any notifications to show.</div></div>"
-	var/list/outdated_tabs = list()
+	user << browse('html/templates/welcome_screen.html', "window=greeting;size=640x500")
+
+/*
+ * Sends data to the JS controllers used in the server greeting.
+ * Also updates the user's preferences, if any of the hashes were out of date.
+ * Args:
+ * - var/user client
+ * - var/outdated_info int
+ */
+/datum/server_greeting/proc/send_to_javascript(var/client/user)
+	if (!user)
+		return
+
+	// This is fine now, because it uses cached information.
+	var/outdated_info = server_greeting.find_outdated_info(user)
+
 	var/save_prefs = 0
+	var/list/data = list("div" = "", "content" = "", "update" = 1)
 
 	if (outdated_info & OUTDATED_NOTE)
-		outdated_tabs += "#note-tab"
+		user << output("#note-placeholder", "greeting.browser:RemoveElement")
+
+		data["div"] = "#note"
+		data["update"] = 1
 
-		notifications = ""
 		for (var/datum/client_notification/a in user.prefs.notifications)
-			notifications += a.get_html()
+			data["content"] = a.get_html()
+			user << output(JS_SANITIZE(data), "greeting.browser:AddContent")
 
-	if (outdated_info & OUTDATED_MEMO)
-		outdated_tabs += "#memo-tab"
-		user.prefs.memo_hash = memo_hash
-		save_prefs = 1
+	if (!user.holder)
+		user << output("#memo-tab", "greeting.browser:RemoveElement")
+	else
+		if (outdated_info & OUTDATED_MEMO)
+			data["update"] = 1
+			user.prefs.memo_hash = memo_hash
+			save_prefs = 1
+		else
+			data["update"] = 0
+
+		data["div"] = "#memo"
+		data["content"] = memo
+		user << output(JS_SANITIZE(data), "greeting.browser:AddContent")
 
 	if (outdated_info & OUTDATED_MOTD)
-		outdated_tabs += "#motd-tab"
+		data["update"] = 1
 		user.prefs.motd_hash = motd_hash
 		save_prefs = 1
+	else
+		data["update"] = 0
 
-	var/data = user_data
-
-	if (user.holder)
-		data = staff_data
-
-	data = replacetextEx(data, "<!--note-->", notifications)
-
-	if (outdated_tabs.len)
-		var/tab_string = json_encode(outdated_tabs)
-		data = replacetextEx(data, "var updated_tabs = \[\]", "var updated_tabs = [tab_string]")
-
-	user << browse(data, "window=welcome_screen;size=640x500")
+	data["div"] = "#motd"
+	data["content"] = motd
+	user << output(JS_SANITIZE(data), "greeting.browser:AddContent")
 
 	if (save_prefs)
 		user.prefs.handle_preferences_save(user)
 
+/*
+ * Basically the Topic proc for the greeting datum.
+ */
+/datum/server_greeting/proc/handle_call(var/href_list, var/client/C)
+	if (!href_list || !href_list["command"] || !C)
+		return
+
+	switch (href_list["command"])
+		if ("request_data")
+			send_to_javascript(C)
+
 #undef OUTDATED_NOTE
 #undef OUTDATED_MEMO
 #undef OUTDATED_MOTD