Added support for empty tags

Also support for <br/> tag

Author: britzl

README.md

@@ -45,7 +45,11 @@ The following tags are supported:
 |       |                                                | `<color=1.0,0.5,0,1.0>Foobar</color>` |
 |       |                                                | `<color=#ff00ffff>Foobar</color>`     |
 | font  | Change font                                    | `<font=MyCoolFont>Foobar</font>`      |
-| img   | Display image                                  | `<img=texture:image></img>`           |
+| img   | Display image                                  | `<img=texture:image/>`                |
+| br    | Insert a line break (see notes on linebreak)   | `<br/>`                               |
+
+### Line breaks
+Note that there is no need for the HTML `<br/>` tag since line breaks (i.e. `\n`) are parsed and presented by the system.
 
 ### Named colors
 The following named colors are supported:
@@ -75,9 +79,6 @@ The following named colors are supported:
 | white     | `#ffffffff` | ![](https://placehold.it/15/ffffff/000000?text=+) |
 | yellow    | `#ffff00ff` | ![](https://placehold.it/15/ffff00/000000?text=+) |
 
-## Line breaks
-There is no need for the HTML `<br>` tag since line breaks (i.e. `\n`) are parsed and presented by the system.
-
 # Usage
 The RichText library will create gui text nodes representing the markup in the text passed to the library. It will search for tags and split the entire text into words, where each word contains additional meta-data that is used to create and configure text nodes. This means that the library will create as many text nodes as there are words in the text. Example:
 
@@ -99,7 +100,7 @@ The RichText library will create gui text nodes representing the markup in the t
 		color = vmath.vector4(0.95, 0.95, 1.0, 1.0),
 	}
 
-	local text = "<size=3>RichText</size>Lorem <color=0,0.5,0,1>ipsum </color><img=smileys:zombie></img> dolor <color=red>sit </color><color=#ff00ffff>amet, </color><size=1.15><font=Nanum>consectetur </font></size>adipiscing elit. <b>Nunc </b>tincidunt <b><i>mattis</i> libero</b> <i>non viverra</i>.\n\nNullam ornare <img=smileys:hungry></img>accumsan rhoncus.\n\nNunc placerat nibh a purus auctor, id scelerisque massa <size=2>rutrum.</size>"
+	local text = "<size=3>RichText</size>Lorem <color=0,0.5,0,1>ipsum </color><img=smileys:zombie/> dolor <color=red>sit </color><color=#ff00ffff>amet, </color><size=1.15><font=Nanum>consectetur </font></size>adipiscing elit. <b>Nunc </b>tincidunt <b><i>mattis</i> libero</b> <i>non viverra</i>.\n\nNullam ornare <img=smileys:hungry/>accumsan rhoncus.\n\nNunc placerat nibh a purus auctor, id scelerisque massa <size=2>rutrum.</size>"
 
 	richtext.create(text, "Roboto", settings)
 

example/example.gui_script

@@ -1,6 +1,6 @@
 local richtext = require "richtext.richtext"
 
-local TEXT = "<size=3>RichText</size>Lorem <color=0,0.5,0,1>ipsum </color><img=smileys:zombie></img> dolor <color=red>sit </color><color=#ff00ffff>amet, </color><size=1.15><font=Nanum>consectetur </font></size>adipiscing elit. <b>Nunc </b>tincidunt <b><i>mattis</i> libero</b> <i>non viverra</i>.\n\nNullam ornare <img=smileys:hungry></img>accumsan rhoncus.\n\nNunc placerat nibh a purus auctor, id scelerisque massa <size=2>rutrum.</size>"
+local TEXT = "<size=3>RichText</size>Lorem <color=0,0.5,0,1>ipsum </color><img=smileys:zombie/> dolor <color=red>sit </color><color=#ff00ffff>amet, </color><size=1.15><font=Nanum>consectetur </font></size>adipiscing elit.<br/><b>Nunc </b>tincidunt <b><i>mattis</i> libero</b> <i>non viverra</i>.\n\nNullam ornare <img=smileys:hungry></img>accumsan rhoncus.\n\nNunc placerat nibh a purus auctor, id scelerisque massa <size=2>rutrum.</size>"
 
 function init(self)
 	local settings = {

richtext/parse.lua

@@ -14,6 +14,8 @@ local function parse_tag(tag, params)
 		settings.bold = true
 	elseif tag == "i" then
 		settings.italic = true
+	elseif tag == "br" then
+		settings.linebreak = true
 	elseif tag == "img" then
 		local texture, anim = params:match("(.-):(.*)")
 		settings.image = {
@@ -60,18 +62,29 @@ local function split_text(text, settings, words)
 	assert(text)
 	assert(settings)
 	assert(words)
+
+	-- special treatment of empty text with a linebreak <br/>
+	if text == "" and settings.linebreak then
+		add_word(text, settings, words)
+		return
+	end
+
+	-- the Lua pattern expects the text to have a linebreak at the end
 	local added_linebreak = false
 	if text:sub(-1)~="\n" then
 		added_linebreak = true
 		text = text .. "\n"
 	end
 
+	-- split into lines
 	for line in text:gmatch("(.-)\n") do
 		split_line(line, settings, words)
+		-- flag last word of a line as having a linebreak
 		local last = words[#words]
 		last.linebreak = true
 	end
 
+	-- remove the last linebreak if we manually added it above
 	if added_linebreak then
 		local last = words[#words]
 		last.linebreak = false
@@ -83,13 +96,19 @@ end
 local function find_tag(text)
 	assert(text)
 	-- find tag, end if no tag was found
-	local before_start_tag, tag, after_start_tag = text:match("(.-)(<[^/]%S->)(.*)")
+	local before_start_tag, tag, after_start_tag = text:match("(.-)(</?%S->)(.*)")
 	if not before_start_tag or not tag or not after_start_tag then
 		return nil
 	end
 
 	-- parse the tag, split into name and optional parameters
-	local name, params = tag:match("<(%a+)=?(%S*)>")
+	local name, params, empty = tag:match("<(%a+)=?(%S-)(/?)>")
+
+	-- empty tag, ie tag without content
+	-- example <br/> and <img=texture:image/>
+	if empty == "/" then
+		return before_start_tag, name, params, "", after_start_tag
+	end
 
 	-- find end tag
 	local inside_tag, after_end_tag = after_start_tag:match("(.-)</" .. name .. ">(.*)")