Update weather widget type to use Awesome async API

Timeout for fetching data could be removed
since this widget would run on another thread.

README.md

@@ -398,7 +398,8 @@ Provides number of pending updates on UNIX systems. Be aware that some package
 managers need to update their local databases (as root) before showing the
 correct number of updates.
 
-Supported platforms: platform independent.
+Supported platforms: platform independent, although it requires Awesome
+`awful.spawn` library for non-blocking spawning.
 
 * Argument: distribution name, e.g. `"Arch"`, `"Arch C"`, `"Arch S"`,
   `"Debian"`, `"Ubuntu"`, `"Fedora"`, `"FreeBSD"`, `"Mandriva"`.
@@ -481,7 +482,7 @@ Supported platforms: GNU/Linux (requiring `amixer`), FreeBSD.
 
 Provides weather information for a requested station.
 
-Supported platforms: any having `curl` installed.
+Supported platforms: any having Awesome and `curl` installed.
 
 * Argument: the ICAO station code, e.g. `"LDRI"`
 * Returns a table with string keys: `${city}`, `${wind}`, `${windmph}`,

widgets/weather_all.lua

@@ -9,6 +9,10 @@ local io = { popen = io.popen }
 local setmetatable = setmetatable
 local math = { ceil = math.ceil }
 local string = { match = string.match }
+
+-- Awesome library for spawning programs
+local spawn = require"awful.spawn"
+
 local helpers = require("vicious.helpers")
 -- }}}
 
@@ -18,6 +22,8 @@ local helpers = require("vicious.helpers")
 local weather_all = {}
 
 
+-- {{{ Weather widget type
+local function parse(ws)
     -- Initialize function tables
     local _weather = {
         ["{city}"]    = "N/A",
@@ -34,19 +40,8 @@ local _weather = {
         ["{press}"]   = "N/A"
     }
 
--- {{{ Weather widget type
-local function worker(format, warg)
-    if not warg then return end
-
-    -- Get weather forceast by the station ICAO code, from:
-    -- * US National Oceanic and Atmospheric Administration
-    local url = "https://tgftp.nws.noaa.gov/data/observations/metar/decoded/"..warg
-    local f = io.popen("curl --connect-timeout 1 -fsm 3 "..helpers.shellquote(url)..".TXT")
-    local ws = f:read("*all")
-    f:close()
-
     -- Check if there was a timeout or a problem with the station
-    if ws == nil then return _weather end
+    if ws == '' then return _weather end
 
     _weather["{city}"]    = -- City and/or area
        string.match(ws, "^(.+)%,.*%([%u]+%)") or _weather["{city}"]
@@ -89,6 +84,23 @@ local function worker(format, warg)
 
     return _weather
 end
+
+function weather_all.async(format, warg, callback)
+    if not warg then return end
+
+    -- Get weather forceast by the station ICAO code, from:
+    -- * US National Oceanic and Atmospheric Administration
+    local url = ("https://tgftp.nws.noaa.gov/data/observations/metar/decoded/%s.TXT"):format(warg)
+    local cmd = "curl -fs " .. helpers.shellquote(url)
+    spawn.easy_async(cmd, function (stdout) callback(parse(stdout)) end)
+end
+
+local function worker(format, warg)
+    local ret
+    weather_all.async(format, warg, function (weather) ret = weather end)
+    while ret == nil do end
+    return ret
+end
 -- }}}
 
 return setmetatable(weather_all, { __call = function(_, ...) return worker(...) end })