Allow scrolling on index page

assets/index_scroll.js

@@ -0,0 +1,107 @@
+/*
+Allows for lazy loading of stories on the main page as the user scrolls down
+*/
+
+
+function add_stories(stories){
+	var tbody_el = document.querySelector("table#story_list tbody")
+	for(var i = 0; i < stories.length; i++){
+		var story = stories[i];
+		/* This chunk should match /src/pages/parts/story_brief */
+		console.log("Adding story:",story)
+		var row = document.createElement("tr");
+		row.appendChild(
+			document.createElement("td")
+		); // unlisted cell
+		var link_cell = document.createElement("td");
+		var link = document.createElement("a");
+		link.textContent = story.title;
+		link.href = story.url;
+		link_cell.appendChild(link);
+		row.appendChild(link_cell);
+
+		var author_cell = document.createElement("td");
+		author_cell.appendChild(
+			document.createTextNode("By ")
+		);
+		if(story.isanon){
+			author_cell.appendChild(
+				document.createTextNode("Anonymous")
+			);
+		}else{
+			var author_page = document.createElement("a");
+			author_page.textContent = story.author;
+			author_page.href = story.author; // TODO: fix
+			author_cell.appendChild(author_page);
+		}
+		row.appendChild(author_cell);
+		var hits_cell = document.createElement("td")
+		hits_cell.appendChild(
+			document.createTextNode(story.hits + " hits")
+		);
+		row.appendChild(hits_cell);
+		var comments_cell = document.createElement("td");
+		comments_cell.appendChild(
+			document.createTextNode(story.ncomments + " comments")
+		);
+		row.appendChild(comments_cell);
+		var tag_cell = document.createElement("td");
+		var tag_list = document.createElement("ul");
+		tag_list.className = "row tag-list";
+		tag_cell.appendChild(tag_list);
+		for(var j = 0; j < Math.min(story.tags.length,5); j++){
+			var tag = story.tags[j];
+			var tag_item = document.createElement("li");
+			var tag_button = document.createElement("a");
+			tag_button.className = "tag button button-outline";
+			tag_button.textContent = tag;
+			tag_button.href = "/_search?q=%2B" + tag;
+			tag_item.appendChild(tag_button);
+			tag_list.appendChild(tag_item);
+		}
+		row.appendChild(tag_cell);
+		var date_cell = document.createElement("td");
+		date_cell.appendChild(
+			document.createTextNode(story.posted)
+		);
+		row.appendChild(date_cell);
+		tbody_el.appendChild(row);
+	}
+}
+
+/*
+A tiny state machine:
+0 - idle
+1 - loading more stories (do not send another request)
+2 - stories loaded, waiting for next scroll event to transition to idle
+*/
+var state = 0
+var loaded = 50 // by default we load 50 stories on the site index
+document.addEventListener("scroll",function(e){
+	var tobot = window.scrollMaxY - window.scrollY
+	if (tobot < 100){
+		if (state == 0){
+			//Ask the server for stories
+			// TODO: Finish this
+			var xhr = new XMLHttpRequest();
+			xhr.open("GET", "/_api?call=stories&data=" + loaded);
+			xhr.onreadystatechange = function(e){
+				if(xhr.readyState === 4){
+					console.log("response:",xhr.response)
+					resp = JSON.parse(xhr.response);
+					console.log("resp:",resp)
+					add_stories(resp.stories);
+					loaded += resp.stories.length;
+				}
+				state = 2
+			}
+			xhr.send()
+			state = 1
+		}else if (state == 1){
+			// Do nothing
+		}else if (state == 2){
+			state = 0
+		}
+		console.log("we should load more stories")
+	}
+})

conf/smr.conf.in

@@ -89,6 +89,11 @@ domain * {
 		handler asset_serve_intervine_deletion_js
 		methods get
 	}
+	
+	route /_js/index_scroll.js {
+		handler asset_serve_index_scroll_js
+		methods get
+	}
 
 	route /favicon.ico {
 		handler asset_serve_favicon_ico

src/lua/addon.lua

@@ -0,0 +1,23 @@
+--[[
+Addon loader - Addons are either:
+* A folder with at least two files:
+  - meta.lua - contains load order information
+  - init.lua - entrypoint that gets run to load the addon
+* A zip file with the same
+* A sqlite3 database with a table "files" that has at least the columns
+  * name :: TEXT - The filename
+  * data :: BINARY - The file data
+  And there are at least 2 rows with filenames `meta.lua` and `init.lua`
+  as described above. Addons should be placed in $SMR_ADDONS, defined in config.lua
+
+The `meta.lua` file is run at worker init time (i.e. it will be run once for
+each worker), and should return a table with at least the following information
+{
+	name :: string - A name for the addon (all addons must have unique names)
+	desc :: string - A description for the addon.
+	entry :: table[number -> string] - Describes the load order for this
+		addon. Each addon's meta.lua is run, and sorted to get a load
+		order for entrypoints (the strings are the names files)
+]]
+
+

src/lua/endpoints/api_get.lua

@@ -3,16 +3,25 @@ local sql = require("lsqlite3")
 local db = require("db")
 local queries = require("queries")
 local util = require("util")
+local tags = require("tags")
+require("global")
 
-local stmnt_tags_get
+local stmnt_tags_get, stmnt_stories_get
 
 local oldconfigure = configure
 function configure(...)
 	stmnt_tags_get = db.sqlassert(db.conn:prepare(queries.select_suggest_tags))
+	stmnt_stories_get = db.sqlassert(db.conn:prepare(queries.select_site_index))
 	return oldconfigure(...)
 end
 
 local function suggest_tags(req,data)
+	--[[
+	Prevent a malicious user from injecting '%' into the string
+	we're searching for, potentially causing a DoS with a
+	sufficiently backtrack-ey search/tag combination.
+	]]
+	assert(data:match("^[a-zA-Z0-9,%s-]+$"),string.format("Bad characters in tag: %q",data))
 	stmnt_tags_get:bind_names{
 		match = data .. "%"
 	}
@@ -25,19 +34,93 @@ local function suggest_tags(req,data)
 	http_response(req,200,table.concat(tags,";"))
 end
 
+--[[
+A poor mans json builder, since I don't need one big enough to pull in a
+dependency for it (yet)
+]]
+local function poor_json(builder, ltbl)
+	local function write_bool(builder,bool)
+		table.insert(builder,bool and "true" or "false")
+	end
+	local function write_number(builder,num)
+		local number
+		if num % 1 == 0 then
+			num = string.format("%d",num)
+		else
+			num = string.format("%f",num)
+		end
+		table.insert(builder,num)
+	end
+	local function write_string(builder,s)
+		table.insert(builder, string.format("%q",s))
+	end
+	local function write_array(builder,tbl)
+		table.insert(builder,"[")
+		for _,item in ipairs(tbl) do
+			write_string(builder,item)
+			table.insert(builder,",")
+		end
+		if #tbl > 0 then
+			table.remove(builder,#builder) -- Remove the last comma
+		end
+		table.insert(builder,"]")
+	end
+	local lua_to_json = {
+		boolean = write_bool,
+		number = write_number,
+		string = write_string,
+		table = write_array
+	}
+	table.insert(builder,"{")
+	for k,v in pairs(ltbl) do
+		assert(type(k) == "string", "Field was not a string, was: " .. type(k))
+		table.insert(builder,string.format("%q",k))
+		table.insert(builder,":")
+		assert(lua_to_json[type(v)], "Unknown type for json:" .. type(v) .. " at " .. k)
+		lua_to_json[type(v)](builder,v)
+		table.insert(builder,",")
+	end
+	table.remove(builder,#builder) -- Remove the last comma before closing object
+	table.insert(builder,"}")
+	table.insert(builder,",") -- Can't do this on the same line as above
+	                          -- we need to remove the last comma, but not }
+end
+
+local function get_stories(req,data)
+	local nstories = tonumber(data)
+	stmnt_stories_get:bind_names{offset=nstories}
+	local builder = setmetatable({'{"stories":['},table)
+	for id, title, anon, time, author, hits, ncomments in db.sql_rows(stmnt_stories_get) do
+		local story = {
+			url = util.encode_id(id),
+			title = title,
+			isanon = tonumber(anon) == 1,
+			posted = os.date("%B %d %Y",tonumber(time)),
+			author = author,
+			tags = tags.get(id),
+			hits = hits,
+			ncomments = ncomments
+		}
+		poor_json(builder,story)
+	end
+	table.remove(builder,#builder) -- Remove last comma before closing list
+	table.insert(builder,"]}")
+	stmnt_stories_get:reset()
+	http_response_header(req,"Content-Type","text/plain")
+	http_response(req,200,table.concat(builder))
+end
+
+local api_points = {}
+local function register_api(call,func)
+	api_points[call] = func
+end
+register_api("suggest",suggest_tags)
+register_api("stories",get_stories)
 local function api_get(req)
 	http_request_populate_qs(req)
 	local call = assert(http_argument_get_string(req,"call"))
 	local data = assert(http_argument_get_string(req,"data"))
-	local body
-	if call == "suggest" then
-		--[[
-		Prevent a malicious user from injecting '%' into the string
-		we're searching for, potentially causing a DoS with a
-		sufficiently backtrack-ey search/tag combination.
-		]]
-		assert(data:match("^[a-zA-Z0-9,%s-]+$"),string.format("Bad characters in tag: %q",data))
-		return suggest_tags(req,data)
-	end
+	assertf(api_points[call], "Unknown api endpoint: %s", call)
+	api_points[call](req,data)
 end
 return api_get

src/lua/global.lua

@@ -7,3 +7,49 @@ function assertf(bool, fmt, ...)
 		error(string.format(fmt,...),2)
 	end
 end
+
+
+function errorf(str, ...)
+	--try calling string.format, if it errors, try calling it with exactly
+	--1 less argument (the error level)
+	local args = {...}
+	local succ, ret = pcall(string.format,str,...)
+	if not succ and type(args[#args]) ~= "number" then
+		errorf("Failed displaying error that looks like %q",str)
+	elseif type(args[#args]) == "number" then
+		local errlevel = table.remove(args,#args)
+		local succ2, ret = pcall(string.format,str,unpack(args))
+		if not succ2 then
+			errorf("Failed displaying error that looks like %q",str)
+		end
+		error(ret, errlevel+1)
+	end
+	error(ret,2)
+end
+
+local oldtostring = tostring
+function tostring(any)
+	--Pretty print tables by default
+	local printed_tables = {}
+	local function tostring_helper(a,tabs)
+		if type(a) ~= "table" then
+			return oldtostring(a)
+		end
+		if printed_tables[a] then
+			return oldtostring(a)
+		end
+		printed_tables[a] = true
+		local sbuilder = {"{\n"}
+		for k,v in pairs(a) do
+			table.insert(sbuilder,string.rep("\t",tabs))
+			table.insert(sbuilder,tostring_helper(k,tabs+1))
+			table.insert(sbuilder,":")
+			table.insert(sbuilder,tostring_helper(v,tabs+1))
+			table.insert(sbuilder,"\n")
+		end
+		table.insert(sbuilder,string.rep("\t",tabs-1))
+		table.insert(sbuilder,"}")
+		return table.concat(sbuilder)
+	end
+	return tostring_helper(any,1)
+end

src/lua/hooks.lua

@@ -1,21 +1,24 @@
 --[[
-Global functions that smr exposes that can be overriden by addons
+Global functions that smr exposes that can be detoured by addons
 ]]
 
 local api = {}
 
 -- Called before any request processing. Returning true "traps" the request, and
--- does not continue calling smr logic, or logic of any other addons.
+-- does not continue calling smr logic. Well-behaved addons should check for
+-- "true" from the detoured function, and return true immediately if the check 
+-- succeeds.
 api.pre_request = function(req) end
 
--- Called after smr request processing. Returning true "traps" the request, and
--- does not continue calling any other addon logic. This will not stop smr from
+-- Called after smr request processing. Returning true "traps" the request. 
+-- Well-behaved addons should check for true from the detoured function, and
+-- immediately return true if the check succeeds. This will not stop smr from
 -- responding to the request, since by this time http_request_response() has
 -- already been called.
 api.post_request = function(req) end
 
 -- Called during startup of the worker process
--- Failures in this function will prevent kore from starting.
+-- calling error() in this function will prevent kore from starting.
 -- Return value is ignored.
 api.worker_init = function() end
 
@@ -42,4 +45,7 @@ api.get = {
 	page_reader = function(env) return {} end,
 }
 
+-- Called when the /_api endpoint is accessed
+api.call = function() end
+
 return api

src/lua/pages.lua

@@ -3,6 +3,7 @@ Compiles all the pages under src/pages/ with etlua. See the etlua documentation
 for more info (https://github.com/leafo/etlua)
 ]]
 local et = require("etlua")
+require("global")
 local pagenames = {
 	"index",
 	"author_index",

src/pages/index.etlua.in

@@ -28,7 +28,7 @@
 	<% if #stories == 0 then %>
 	No stories available.
 	<% else %>
-		<table>
+		<table id="story_list">
 		<% for k,story in pairs(stories) do %>
 			<{system cat src/pages/parts/story_breif.etlua}>
 		<% end %>