When I run the following code via lua5.1 everything runs properly but when the same code via openresty I get the error below. Having said that, When I run getAttribute() (via openresty), I get the correct HTML element back which I think means that that gumbo and lua-gumbo are installed properly. Why is documentElement a nil value?
# cat /usr/local/openresty/nginx/logs/error.log
2014/11/01 18:05:51 [error] 15463#0: *17399 lua entry thread aborted: runtime error: /usr/local/openresty/nginx/conf/test.lua:34: attempt to index field 'documentElement' (a nil value)
stack traceback:
coroutine 0:
# cat test.lua
local gumbo = require "gumbo"
local input = [[
<html>
<head></head>
<body>
<form action="">
<input id="username" name="username1"/>
<input id="password" name="password1"/>
<input type="submit"/>
</form>
<a href="">Acme</a>
<img src="" alt="Smiley face" height="42" width="42">
</body>
</html>
]]
local function findSmiley(baseNode)
if not baseNode or baseNode:hasChildNodes() == false then return nil end
for node in baseNode:walk() do
if node.type == "element"
and node.localName == "img"
and node:getAttribute("src") == "smiley.gif"
then
return node
end
end
end
local document = assert(gumbo.parse(input))
local smiley = assert(findSmiley(document))
smiley:setAttribute("src", "NEW-SRC.gif")
--io.write(document.documentElement.outerHTML, "\n")
ngx.say(document.documentElement.outerHTML)
