view mod_pubsub_summary/mod_pubsub_summary.lua @ 4651:8231774f5bfd

mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8 The `body:sub()` call risks splitting the string in the middle of a multi-byte UTF-8 sequence. This should have been caught by util.stanza validation, but that would have caused some havoc, at the very least causing the notification to not be sent. There have been no reports of this happening. Likely because this module isn't widely deployed among users with languages that use many longer UTF-8 sequences. The util.encodings.utf8.valid() function is O(n) where only the last sequence really needs to be checked, but it's in C and expected to be fast.
author Kim Alvefur <zash@zash.se>
date Sun, 22 Aug 2021 13:22:59 +0200
parents fcfe691d6322
children cde38b7de04a
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-- No, not trying to parse HTML here. It's an illusion. Just trying to read RSS feeds.
--
-- Compose a textual representation of Atom payloads
module:hook("pubsub-summary/http://www.w3.org/2005/Atom", function (event)
	local payload = event.payload;
	local title = payload:get_child_text("title");
	-- Note: This prefers content over summary, it was made for a news feed where
	-- the interesting stuff was in the content and the summary was .. meh.
	local content_tag = payload:get_child("content") or payload:get_child("summary");
	local content = content_tag and content_tag:get_text();
	if content and content_tag.attr.type == "html" then
		content = content:gsub("\n*<p[^>]*>\n*(.-)\n*</p>\n*", "%1\n\n");
		content = content:gsub("<li>(.-)</li>\n", "* %1\n");
		content = content:gsub("<a[^>]*href=[\"'](.-)[\"'][^>]*>(.-)</a>", "\1%1\2%2\3");
		content = content:gsub("<b>(.-)</b>", "*%1*");
		content = content:gsub("<strong>(.-)</strong>", "*%1*");
		content = content:gsub("<em>(.-)</em>", "_%1_");
		content = content:gsub("<i>(.-)</i>", "_%1_");
		content = content:gsub("<img[^>]*src=[\"'](.-)[\"'][^>]*>", " %1 "); -- TODO alt= would have been nice to grab
		content = content:gsub("<br[^>]*>", "\n");
		content = content:gsub("<[^>]+>", "");
		content = content:gsub("\1(.-)\2(.-)\3", "%2 <%1>");
		content = content:gsub("^%s*", ""):gsub("%s*$", "");
		content = content:gsub("\n\n\n+", "\n\n");
		content = content:gsub("&(%w+);", {
				apos = "'";
				quot = '"';
				lt = "<";
				gt = ">";
				amp = "&";
				nbsp = "\194\160"; -- U+00A0
			});
	end
	local summary;
	if title and content and content:sub(1, #title) ~= title then
		summary = "*" .. title .. "*\n\n" .. content;
	elseif title or content then
		summary = content or title;
	end
	for link in payload:childtags("link") do
		if link and link.attr.href and link.attr.href ~= content then
			summary = (summary and summary .. "\n" or "") .. link.attr.href;
			if link.attr.rel then summary = summary .. " [" .. link.attr.rel .. "]" end
		end
	end
	return summary;
end, 1);