lua-htmlparser/src/htmlparser.lua at master · lineCode/lua-htmlparser · GitHub

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-- vim: ft=lua ts=2 sw=2

local esc = function(s) return string.gsub(s, "([%^%$%(%)%%%.%[%]%*%+%-%?])", "%%" .. "%1") end

local str = tostring

local char = string.char

local err = function(s) io.stderr:write(s) end

local out = function(s) io.stdout:write(s) end

local ElementNode = require("htmlparser.ElementNode")

local voidelements = require("htmlparser.voidelements")

local HtmlParser = {}

local tpr = {

-- Here we're replacing confusing sequences

-- (things looking like tags, but appearing where tags can't)

-- with definitelly invalid utf sequence, and later we'll replace them back

["<"] = char(208,209,208,209),

[">"] = char(209,208,209,208),

}

local function parse(text,limit)

local text=str(text)

local limit = limit or htmlparser_looplimit or 1000

local tpl = false

local function g(id,...)

local arg={...}

arg[id]=tpr[arg[id]]

tpl=true

return table.concat(arg)

end

text = text

:gsub(

"(<)"..

"([^>]-)"..

"(<)",

function(...)return g(3,...)end

):gsub(

"("..tpr["<"]..")"..

"([^%w%s])"..

"([^%2]-)"..

"(%2)"..

"(>)"..

"([^>]-)"..

"(>)",

function(...)return g(5,...)end

):gsub(

[=[(['"])]=]..

[=[([^'">%s]-)]=]..

"(>)"..

[=[([^'">%s]-)]=]..

[=[(['"])]=],

function(...)return g(3,...)end

)

local index = 0

local root = ElementNode:new(index, str(text))

local node, descend, tpos, opentags = root, true, 1, {}

while true do

if index == limit then

err("[HTMLParser] [ERR] Main loop reached loop limit ("..limit.."). Please, consider increasing it or check the code for errors")

break

end

local openstart, name

openstart, tpos, name = root._text:find(

"<" .. -- an uncaptured starting "<"

"([%w-]+)" .. -- name = the first word, directly following the "<"

"[^>]*>", -- include, but not capture everything up to the next ">"

tpos)

if not name then break end

index = index + 1

local tag = ElementNode:new(index, str(name), node, descend, openstart, tpos)

node = tag

local tagloop

local tagst, apos = tag:gettext(), 1

while true do

if tagloop == limit then

err("[HTMLParser] [ERR] tag parsing loop reached loop limit ("..limit.."). Please, consider increasing it or check the code for errors")

break

end

local start, k, eq, quote, v

start, apos, k, eq, quote = tagst:find(

"%s+" .. -- some uncaptured space

"([^%s=/>]+)" .. -- k = an unspaced string up to an optional "=" or the "/" or ">"

"(=?)" .. -- eq = the optional; "=", else ""

"(['\"]?)", -- quote = an optional "'" or '"' following the "=", or ""

apos)

if not k or k == "/>" or k == ">" then break end

if eq == "=" then

pattern = "=([^%s>]*)"

if quote ~= "" then

pattern = quote .. "([^" .. quote .. "]*)" .. quote

end

start, apos, v = tagst:find(pattern, apos)

end

v=v or ""

if tpl then

for rk,rv in pairs(tpr) do

v = v:gsub(rv,rk)

end

tag:addattribute(k, v)

tagloop = (tagloop or 0) + 1

end

if voidelements[tag.name:lower()] then

descend = false

tag:close()

else

opentags[tag.name] = opentags[tag.name] or {}

table.insert(opentags[tag.name], tag)

end

local closeend = tpos

local closingloop

while true do

if closingloop == limit then

err("[HTMLParser] [ERR] tag closing loop reached loop limit ("..limit.."). Please, consider increasing it or check the code for errors")

break

end

local closestart, closing, closename

closestart, closeend, closing, closename = root._text:find("[^<]*<(/?)([%w-]+)", closeend)

if not closing or closing == "" then break end

tag = table.remove(opentags[closename] or {}) or tag -- kludges for the cases of closing void or non-opened tags

closestart = root._text:find("<", closestart)

tag:close(closestart, closeend + 1)

node = tag.parent

descend = true

closingloop = (closingloop or 0) + 1

end

if tpl then

for k,v in pairs(tpr) do

root._text = root._text:gsub(v,k)

end

return root

end

HtmlParser.parse = parse

return HtmlParser

lua-htmlparser/src/htmlparser.lua at master · lineCode/lua-htmlparser · GitHub

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