Barebones interface to the openweathermap.org web API.

Cache and rate limiting is useless right now unless calling script is long-lived.

exec/load/openweathermap.js

+// Uses OpenWeatherMap, openweathermap.org
+// CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0/
+// Sign up for your account & API key here: https://openweathermap.org/api
+// Add an [openweathermap] section to modopts.ini
+// Add an api_key value to that section with your key
+// rate_window, rate_limit, and data_refresh values can be added as well,
+// but the defaults are suited to the free tier.
+
+load('http.js');
+load('modopts.js');
+
+function OpenWeatherMap() {
+    this.settings = get_mod_options('openweathermap');
+    if (!this.settings.rate_window) this.settings.rate_window = 60; // Seconds
+    if (!this.settings.rate_limit) this.settings.rate_limit = 60; // Requests per window
+    if (!this.settings.data_refresh) this.settings.data_refresh = 7200; // Seconds
+    this.cache = {};
+    this.requests = [];
+}
+
+OpenWeatherMap.prototype.write_cache = function (endpoint, params, response) {
+    const hash = base64_encode(endpoint + JSON.stringify(params));
+    this.cache[hash] = { time: time(), data: response };
+}
+
+OpenWeatherMap.prototype.read_cache = function (endpoint, params) {
+    const hash = base64_encode(endpoint + JSON.stringify(params));
+    if (!this.cache[hash]) return;
+    // This is probably not the right way, but it'll do
+    if (time() - this.cache[hash].time > this.settings.data_refresh) return;
+    return this.cache[hash].data;
+}
+
+OpenWeatherMap.prototype.rate_limit = function () {
+    const now = time();
+    this.requests = this.requests.filter(function (e) {
+        return now - e < this.settings.rate_window;
+    }, this);
+    if (this.requests.length < this.settings.rate_limit) {
+        this.requests.push(now);
+        return true;
+    } else {
+        return false;
+    }
+}
+
+OpenWeatherMap.prototype.call_api = function (endpoint, params) {
+
+    const cache = this.read_cache(endpoint, params);
+    if (cache) return cache;
+
+    if (!this.rate_limit()) return { error: 'Rate limit exceeded' };
+
+    var url = 'http://api.openweathermap.org/data/2.5/' + endpoint;
+    url += Object.keys(params).reduce(function (a, c, i) {
+        return a + (i == 0 ? '?' : '&') + c + '=' + params[c];
+    }, '');
+    url += '&APPID=' + this.settings.api_key;
+
+    const response = JSON.parse((new HTTPRequest()).Get(url));
+    this.write_cache(endpoint, params, response);
+
+    return response;
+}