Fix for envcanada Provider to use new Environment Canada weather data access (#3878)

Earlier in 2025, Environment Canada changed the process to access
weather data for Canadian cities. This change was raised in Issue #3822
as a Bug, which is addressed in this Provider update. There are no Magic
Mirror UI changes from this update.

The 'old' method to access Environment Canada involved accessing a
static URL based on a City identifier which would result in an XML
document containing the appropriate weather data.

The 'new' method is a 2 step process. The first step is to access a
time-sensitive URL that contains a list of links to various cities that
have weather data available. The second step requires finding the
correct city in that list based on a City identifier, and then accessing
that unique URL to access an XML document containing the appropriate
weather data.

The changes made to the envcanada Provider code are solely aimed at
using the new 2-step method to access a specified City's weather data.
Since the resulting XML document structure has not changed, no other
code in envcanada required changes.

Note that a ChangeLog entry is included in this PR.

---------

Co-authored-by: Kristjan ESPERANTO <35647502+KristjanESPERANTO@users.noreply.github.com>
Co-authored-by: veeck <gitkraken@veeck.de>

CHANGELOG.md

@@ -59,6 +59,7 @@ Thanks to: @dathbe.
 - [core] Fixed socket.io timeout when server is slow to send notification, notification lost at client (#3380)
 - [tests] refactor AnimateCSS tests after jsdom 27 upgrade (#3891)
 - [weather] Use `apparent_temperature` data from openmeteo's hourly weather for current feelsLikeTemp (#3868).
+- [weather] Updated envcanada Provider to use new database/URL schema for accessing weather data (#3822).
 
 ## [2.32.0] - 2025-07-01
 

modules/default/weather/providers/envcanada.js

@@ -24,6 +24,8 @@
  * with locations you can search under column B (English Names), with the corresponding siteCode under
  * column A (Codes) and provCode under column C (Province).
  *
+ * Acknowledgement: Some logic and code for parsing Environment Canada web pages is based on material from MMM-EnvCanada
+ *
  * License to use Environment Canada (EC) data is detailed here:
  * 	https://eccc-msc.github.io/open-data/licence/readme_en/
  */
@@ -49,6 +51,9 @@ WeatherProvider.register("envcanada", {
 		this.todayTempCacheMax = 0;
 		this.todayCached = false;
 		this.cacheCurrentTemp = 999;
+		this.lastCityPageCurrent = " ";
+		this.lastCityPageForecast = " ";
+		this.lastCityPageHourly = " ";
 	},
 
 	/*
@@ -63,69 +68,158 @@ WeatherProvider.register("envcanada", {
 	 * Override the fetchCurrentWeather method to query EC and construct a Current weather object
 	 */
 	fetchCurrentWeather () {
-		this.fetchData(this.getUrl(), "xml")
+		this.fetchCommon("Current");
-			.then((data) => {
-				if (!data) {
-					// Did not receive usable new data.
-					return;
-				}
-				const currentWeather = this.generateWeatherObjectFromCurrentWeather(data);
-
-				this.setCurrentWeather(currentWeather);
-			})
-			.catch(function (request) {
-				Log.error("Could not load EnvCanada site data ... ", request);
-			})
-			.finally(() => this.updateAvailable());
 	},
 
 	/*
-	 * Override the fetchWeatherForecast method to query EC and construct Forecast weather objects
+	 * Override the fetchWeatherForecast method to query EC and construct Forecast/Daily weather objects
 	 */
 	fetchWeatherForecast () {
-		this.fetchData(this.getUrl(), "xml")
-			.then((data) => {
-				if (!data) {
-					// Did not receive usable new data.
-					return;
-				}
-				const forecastWeather = this.generateWeatherObjectsFromForecast(data);
 
-				this.setWeatherForecast(forecastWeather);
+		this.fetchCommon("Forecast");
-			})
+
-			.catch(function (request) {
-				Log.error("Could not load EnvCanada forecast data ... ", request);
-			})
-			.finally(() => this.updateAvailable());
 	},
 
 	/*
-	 * Override the fetchWeatherHourly method to query EC and construct Forecast weather objects
+	 * Override the fetchWeatherHourly method to query EC and construct Hourly weather objects
 	 */
 	fetchWeatherHourly () {
-		this.fetchData(this.getUrl(), "xml")
+		this.fetchCommon("Hourly");
-			.then((data) => {
-				if (!data) {
-					// Did not receive usable new data.
-					return;
-				}
-				const hourlyWeather = this.generateWeatherObjectsFromHourly(data);
-
-				this.setWeatherHourly(hourlyWeather);
-			})
-			.catch(function (request) {
-				Log.error("Could not load EnvCanada hourly data ... ", request);
-			})
-			.finally(() => this.updateAvailable());
 	},
 
 	/*
-	 * Build the EC URL based on the Site Code and Province Code specified in the config params. Note that the
+	 * Because the process to fetch weather data is virtually the same for Current, Forecast/Daily, and Hourly weather,
-	 * URL defaults to the English version simply because there is no language dependency in the data
+	 * a common module is used to access the EC weather data. The only customization (based on the caller of this routine)
-	 * being accessed. This is only pertinent when using the EC data elements that contain a textual forecast.
+	 * is how the data will be parsed to satisfy the Weather module config in Config.js
+	 *
+	 * Accessing EC weather data is accomplished in 2 steps:
+	 *
+	 * 1. Query the MSC Datamart Index page, which returns a list of all the filenames for all the cities that have
+	 *    weather data currently available.
+	 *
+	 * 2. With the city filename identified, build the appropriate URL and get the weather data (XML document) for the
+	 *    city specified in the Weather module Config information
+	 */
+	fetchCommon (target) {
+		const forecastURL = this.getUrl(); // Get the approriate URL for the MSC Datamart Index page
+
+		Log.debug(`[weather.envcanada] ${target} Index url: ${forecastURL}`);
+
+		this.fetchData(forecastURL, "xml") // Query the Index page URL
+			.then((indexData) => {
+				if (!indexData) {
+					// Did not receive usable new data.
+					Log.info(`weather.envcanada ${target} - did not receive usable index data`);
+					this.updateAvailable(); // If there were issues, update anyways to reset timer
+					return;
+				}
+
+				/**
+				 * With the Index page read, we must locate the filename/link for the specified city (aka Sitecode).
+				 * This is done by building the city filename and searching for it on the Index page. Once found,
+				 * extract the full filename (a unique name that includes dat/time, filename, etc.) and then add it
+				 * to the Index page URL to create the proper URL pointing to the city's weather data. Finally, read the
+				 * URL to pull in the city's XML document so that weather data can be parsed and displayed.
+				 */
+
+				let forecastFile = "";
+				let forecastFileURL = "";
+				const fileSuffix = `${this.config.siteCode}_en.xml`; // Build city filename
+				const nextFile = indexData.body.innerHTML.split(fileSuffix); // Find filename on Index page
+
+				if (nextFile.length > 1) { // Parse out the full unqiue file city filename
+					// Find the last occurrence
+					forecastFile = nextFile[nextFile.length - 2].slice(-41) + fileSuffix;
+					forecastFileURL = forecastURL + forecastFile; // Create full URL to the city's weather data
+				}
+
+				Log.debug(`[weather.envcanada] ${target} Citypage url: ${forecastFileURL}`);
+
+				/*
+				 * If the Citypage filename has not changed since the last Weather refresh, the forecast has not changed and
+				 * and therefore we can skip reading the Citypage URL.
+				 */
+
+				if (target === "Current" && this.lastCityPageCurrent === forecastFileURL) {
+					Log.debug(`[weather.envcanada] ${target} - Newest Citypage has already been seen - skipping!`);
+					this.updateAvailable(); // Update anyways to reset refresh timer
+					return;
+				}
+
+				if (target === "Forecast" && this.lastCityPageForecast === forecastFileURL) {
+					Log.debug(`[weather.envcanada] ${target} - Newest Citypage has already been seen - skipping!`);
+					this.updateAvailable(); // Update anyways to reset refresh timer
+					return;
+				}
+
+				if (target === "Hourly" && this.lastCityPageHourly === forecastFileURL) {
+					Log.debug(`[weather.envcanada] ${target} - Newest Citypage has already been seen - skipping!`);
+					this.updateAvailable(); // Update anyways to reset refresh timer
+					return;
+				}
+
+				this.fetchData(forecastFileURL, "xml") // Read city's URL to get weather data
+					.then((cityData) => {
+						if (!cityData) {
+							// Did not receive usable new data.
+							Log.info(`weather.envcanada ${target} - did not receive usable citypage data`);
+							return;
+						}
+
+						/*
+						 * With the city's weather data read, parse the resulting XML document for the appropriate weather data
+						 * elements to create a weather object. Next, set Weather modules details from that object.
+						 */
+						Log.debug(`[weather.envcanada] ${target} - Citypage has been read and will be processed for updates`);
+
+						if (target === "Current") {
+							const currentWeather = this.generateWeatherObjectFromCurrentWeather(cityData);
+							this.setCurrentWeather(currentWeather);
+							this.lastCityPageCurrent = forecastFileURL;
+						}
+
+						if (target === "Forecast") {
+							const forecastWeather = this.generateWeatherObjectsFromForecast(cityData);
+							this.setWeatherForecast(forecastWeather);
+							this.lastCityPageForecast = forecastFileURL;
+						}
+
+						if (target === "Hourly") {
+							const hourlyWeather = this.generateWeatherObjectsFromHourly(cityData);
+							this.setWeatherHourly(hourlyWeather);
+							this.lastCityPageHourly = forecastFileURL;
+						}
+					})
+					.catch(function (cityRequest) {
+						Log.info(`weather.envcanada ${target} - could not load citypage data from: ${forecastFileURL}`);
+					})
+					.finally(() => this.updateAvailable()); // Update no matter what to reset weather refresh timer
+			})
+			.catch(function (indexRequest) {
+				Log.error(`weather.envcanada ${target} - could not load index data ... `, indexRequest);
+				this.updateAvailable(); // If there were issues, update anyways to reset timer
+			});
+	},
+
+	/*
+	 * Build the EC Index page URL based on current GMT hour. The Index page will provide a list of links for each city
+	 * that will, in turn, provide actual weather data. The URL is comprised of 3 parts:
+	 *
+	 *   Fixed value + Prov code specified in Weather module Config.js + current hour as GMT
 	 */
 	getUrl () {
-		return `https://dd.weather.gc.ca/citypage_weather/xml/${this.config.provCode}/${this.config.siteCode}_e.xml`;
+		let forecastURL = `https://dd.weather.gc.ca/citypage_weather/${this.config.provCode}`;
+		const hour = this.getCurrentHourGMT();
+		forecastURL += `/${hour}/`;
+		return forecastURL;
+	},
+
+	/*
+	 * Get current hour-of-day in GMT context
+	 */
+	getCurrentHourGMT () {
+		const now = new Date();
+		return now.toISOString().substring(11, 13); // "HH" in GMT
 	},
 
 	/*
@@ -151,7 +245,6 @@ WeatherProvider.register("envcanada", {
 		}
 
 		currentWeather.windSpeed = WeatherUtils.convertWindToMs(ECdoc.querySelector("siteData currentConditions wind speed").textContent);
-
 		currentWeather.windFromDirection = ECdoc.querySelector("siteData currentConditions wind bearing").textContent;
 
 		currentWeather.humidity = ECdoc.querySelector("siteData currentConditions relativeHumidity").textContent;
@@ -214,7 +307,7 @@ WeatherProvider.register("envcanada", {
 		/*
 		 * The EC forecast is held in a 12-element array - Elements 0 to 11 - with each day encompassing
 		 * 2 elements. the first element for a day details the Today (daytime) forecast while the second
-		 * element details the Tonight (nightime) forecast. Element 0 is always for the current day.
+		 * element details the Tonight (nighttime) forecast. Element 0 is always for the current day.
 		 *
 		 * However... the forecast is somewhat 'rolling'.
 		 *
@@ -225,7 +318,7 @@ WeatherProvider.register("envcanada", {
 		 *
 		 * But, if the EC forecast is queried in late afternoon, the Current Today forecast will be rolled
 		 * off and Element 0 will contain Current Tonight. From there, the next 5 days will be contained in
-		 * Elements 1/2, 3/4, 5/6, 7/8, and 9/10. As well, Elelement 11 will contain a forecast for a 6th day,
+		 * Elements 1/2, 3/4, 5/6, 7/8, and 9/10. As well, Element 11 will contain a forecast for a 6th day,
 		 * but only for the Today portion (not Tonight). This module will create a 6-day forecast using
 		 * Elements 0 to 11, and will ignore the additional Todat forecast in Element 11.
 		 *
@@ -436,17 +529,17 @@ WeatherProvider.register("envcanada", {
 	 * then it will be displayed ONLY if no POP is present.
 	 *
 	 * POP Logic: By default, we want to show the POP for 'daytime' since we are presuming that is what
-	 * people are more interested in seeing. While EC provides a separate POP for daytime and nightime portions
+	 * people are more interested in seeing. While EC provides a separate POP for daytime and nighttime portions
 	 * of each day, the weather module does not really allow for that view of a daily forecast. There we will
-	 * ignore any nightime portion. There is an exception however! For the Current day, the EC data will only show
+	 * ignore any nighttime portion. There is an exception however! For the Current day, the EC data will only show
-	 * the nightime forecast after a certain point in the afternoon. As such, we will be showing the nightime POP
+	 * the nighttime forecast after a certain point in the afternoon. As such, we will be showing the nighttime POP
 	 * (if one exists) in that specific scenario.
 	 *
 	 * Accumulation Logic: Similar to POP, we want to show accumulation for 'daytime' since we presume that is what
-	 * people are interested in seeing. While EC provides a separate accumulation for daytime and nightime portions
+	 * people are interested in seeing. While EC provides a separate accumulation for daytime and nighttime portions
 	 * of each day, the weather module does not really allow for that view of a daily forecast. There we will
-	 * ignore any nightime portion. There is an exception however! For the Current day, the EC data will only show
+	 * ignore any nighttime portion. There is an exception however! For the Current day, the EC data will only show
-	 * the nightime forecast after a certain point in that specific scenario.
+	 * the nighttime forecast after a certain point in that specific scenario.
 	 */
 	setPrecipitation (weather, foreGroup, today) {
 		if (foreGroup[today].querySelector("precipitation accumulation")) {