Start work on tag suggestions

Start working on getting tag suggestions for pasteing and editing pages.

assets/suggest_tags.js

@@ -0,0 +1,105 @@
+console.log("Hello, world!");
+
+tag_suggestion_list = {
+	list_element: null,
+	suggestion_elements: [],
+}
+
+var lel = document.createElement('div');
+
+/**
+ * Stolen from medium.com/@jh3y
+ * returns x, y coordinates for absolute positioning of a span within a given text input
+ * at a given selection point
+ * @param {object} input - the input element to obtain coordinates for
+ * @param {number} selectionPoint - the selection point for the input
+ */
+function getCursorXY(input, selectionPoint){
+  const {
+    offsetLeft: inputX,
+    offsetTop: inputY,
+  } = input
+  // create a dummy element that will be a clone of our input
+  const div = document.createElement('div')
+  // get the computed style of the input and clone it onto the dummy element
+  const copyStyle = getComputedStyle(input)
+  for (const prop of copyStyle) {
+    div.style[prop] = copyStyle[prop]
+  }
+  // we need a character that will replace whitespace when filling our dummy element if it's a single line <input/>
+  const swap = '.'
+  const inputValue = input.tagName === 'INPUT' ? input.value.replace(/ /g, swap) : input.value
+  // set the div content to that of the textarea up until selection
+  const textContent = inputValue.substr(0, selectionPoint)
+  // set the text content of the dummy element div
+  div.textContent = textContent
+  if (input.tagName === 'TEXTAREA') div.style.height = 'auto'
+  // if a single line input then the div needs to be single line and not break out like a text area
+  if (input.tagName === 'INPUT') div.style.width = 'auto'
+  // create a marker element to obtain caret position
+  const span = document.createElement('span')
+  // give the span the textContent of remaining content so that the recreated dummy element is as close as possible
+  span.textContent = inputValue.substr(selectionPoint) || '.'
+  // append the span marker to the div
+  div.appendChild(span)
+  // append the dummy element to the body
+  document.body.appendChild(div)
+  // get the marker position, this is the caret position top and left relative to the input
+  const { offsetLeft: spanX, offsetTop: spanY } = span
+  // lastly, remove that dummy element
+  // NOTE:: can comment this out for debugging purposes if you want to see where that span is rendered
+  document.body.removeChild(div)
+  // return an object with the x and y of the caret. account for input positioning so that you don't need to wrap the input
+  return {
+    x: inputX + spanX,
+    y: inputY + spanY,
+  }
+}
+
+function display_suggestions(elem, sugg, event){
+	console.log("sugg:",sugg);
+	//Check that the value hasn't change since we fired
+	//off the request
+	recent = elem.value.split(";").pop().trim();
+	if(recent == sugg[0]){
+		var sugx, sugy = getCursorXY(elem,elem.value.length);
+		console.log("Looking at position to display suggestions:",sugx, sugy);
+		for(var i in sugg){
+			console.log("Displaying suggestion:",sugg[i]);
+			lel.setAttribute('style',`left: $(sugx)px; top: $(sugy)px;`);
+		}
+	}
+}
+
+function hint_tags(elem, event){
+	//Get the most recent tag
+	recent = elem.value.split(";").pop().trim();
+	if(recent.length > 0){
+		console.log("Most recent tag:",recent);
+		//Ask the server for tags that look like this
+		xhr = new XMLHttpRequest();
+		xhr.open("GET", "/_api?call=suggest&data=" + recent);
+		xhr.onreadystatechange = function(e){
+			if(xhr.readyState === 4){
+				console.log("Event:",e);
+				suggestions = xhr.response.split(";");
+				console.log("suggestions:",suggestions);
+				display_suggestions(elem,suggestions, event);
+
+			}
+		}
+		xhr.send()
+	}
+}
+
+function init(){
+	tag_el_list = document.getElementsByName("tags");
+	console.assert(tag_el_list.length == 1);
+	tag_el = tag_el_list[0];
+	tag_el.onkeyup = function(event){
+		console.log("Looking at tag:", event);
+		console.log("And element:",tag_el);
+		hint_tags(tag_el, event);
+	}
+}
+document.addEventListener("DOMContentLoaded",init,false);

conf/smr.conf.in

@@ -43,6 +43,7 @@ domain * {
 	route  /_css/milligram.css asset_serve_milligram_css
 	route  /_css/milligram.min.css.map asset_serve_milligram_min_css_map
 	route  /_faq asset_serve_faq_html
+	route  /_js/suggest_tags.js asset_serve_suggest_tags_js
 	route  /favicon.ico asset_serve_favicon_ico
 	route  /_paste  post_story
 	route  /_edit   edit_story
@@ -54,6 +55,7 @@ domain * {
 	route  /_preview preview
 	route  /_search search
 	route  /_archive archive
+	route  /_api api
 	# Leading ^ is needed for dynamic routes, kore says the route is dynamic if it does not start with '/'
 	route  ^/[^_].*  read_story
 
@@ -111,5 +113,8 @@ domain * {
 	params post ^/_claim {
 		validate user v_subdomain
 	}
-
+	params get /_api {
+		validate call v_any
+		validate data v_any
+	}
 }

src/lua/endpoints/api_get.lua

@@ -0,0 +1,62 @@
+local cache = require("cache")
+local sql = require("lsqlite3")
+local db = require("db")
+local queries = require("queries")
+local util = require("util")
+
+local stmnt_tags_get
+
+local oldconfigure = configure
+function configure(...)
+	stmnt_tags_get = util.sqlassert(db.conn:prepare(queries.select_suggest_tags))
+	return oldconfigure(...)
+end
+
+local function suggest_tags(req,data)
+	print("Suggesting tags!")
+	stmnt_tags_get:bind_names{
+		match = data .. "%"
+	}
+	local err = util.do_sql(stmnt_tags_get)
+	if err == sql.ROW or err == sql.DONE then
+		local tags = {data}
+		for tag in stmnt_tags_get:rows() do
+			print("Found tag:",tag[1])
+			table.insert(tags,tag[1])
+		end
+		stmnt_tags_get:reset()
+		http_response_header(req,"Content-Type","text/plain")
+		http_response(req,200,table.concat(tags,";"))
+	else
+		log(LOG_ALERT,"Failed to get tag suggestions in an unusual way:" .. err .. ":" .. db.conn:errmsg())
+		--This is bad though
+		local page = pages.error({
+			errcode = 500,
+			errcodemsg = "Server error",
+			explanation = string.format(
+				"Failed to retreive tags from database:%d:%q",
+				err,
+				db.conn:errmsg()
+			),
+		})
+		stmnt_tags_get:reset()
+		http_response(req,500,page)
+	end
+end
+
+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-]+$"),"Bad characters in tag")
+		return suggest_tags(req,data)
+	end
+end
+return api_get

src/lua/endpoints/edit_get.lua

@@ -61,7 +61,10 @@ local function edit_get(req)
 		story = story_id,
 		err = "",
 		tags = tags_txt,
-		unlisted = unlisted == 1
+		unlisted = unlisted == 1,
+		extra_load = {
+			'<script src="/_js/suggest_tags.js"></script>'
+		}
 	}
 	http_response(req,200,ret)
 end

src/lua/endpoints/paste_get.lua

@@ -19,6 +19,9 @@ local function paste_get(req)
 			return assert(pages.paste{
 				domain = config.domain,
 				err = "",
+				extra_load = {
+					'<script src="/_js/suggest_tags.js"></script>'
+				}
 			})
 		end)
 		http_response(req,200,text)
@@ -29,6 +32,9 @@ local function paste_get(req)
 			user = author,
 			err = "",
 			text="",
+			extra_load = {
+				'<script src="/_js/suggest_tags.js"></script>'
+			}
 		})
 	elseif host ~= config.domain and author == nil then
 		http_response_header(req,"Location",string.format("https://%s/_paste",config.domain))

src/lua/init.lua

@@ -34,6 +34,7 @@ local endpoint_names = {
 	claim    = {"get","post"},
 	search   = {"get"},
 	archive  = {"get"},
+	api      = {"get"},
 }
 local endpoints = {}
 for name, methods in pairs(endpoint_names) do
@@ -151,4 +152,13 @@ function archive(req)
 	endpoints.archive_get(req)
 end
 
+function api(req)
+	local method = http_method_text(req)
+	if method == "GET" then
+		endpoints.api_get(req)
+	elseif method == "POST" then
+		endpoints.api_post(req)
+	end
+end
+
 print("Done with init.lua")

src/pages/edit.etlua.in

@@ -41,7 +41,7 @@
 			<textarea name="text" cols=80 rows=24 class="column"><%= text %></textarea><br/>
 		</div>
 		<input type="submit">
-			
+		<input type="submit" formtarget="_blank" value="Preview" formaction="https://<%= domain %>/_preview">
 	</fieldset>
 </form>
 <{cat src/pages/parts/footer.etlua}>

src/pages/parts/header.etlua

@@ -14,6 +14,11 @@
 		<% end %>
 		<link href="/_css/milligram.css" rel="stylesheet">
 		<link href="/_css/style.css" rel="stylesheet">
+		<% if extra_load then %>
+			<% for _,load in ipairs(extra_load) do %>
+				<%- load %>
+			<% end %>
+		<% end %>
 	</head>
 	<body class="container">
 		<main class="wrapper">

src/smr.c

@@ -26,6 +26,7 @@ int             download(struct http_request *);
 int             preview(struct http_request *);
 int             search(struct http_request *);
 int             archive(struct http_request *);
+int             api(struct http_request *);
 int		style(struct http_request *);
 int		miligram(struct http_request *);
 int             do_lua(struct http_request *req, const char *name);
@@ -179,6 +180,12 @@ archive(struct http_request *req){
 	return do_lua(req,"archive");
 }
 
+int
+api(struct http_request *req){
+	printf("Api call!\n");
+	return do_lua(req,"api");
+}
+
 int
 home(struct http_request *req){
 	return do_lua(req,"home");