Add and edit function documentation

public/js/appChart.js

@@ -81,6 +81,12 @@ export const getDatastreamIdFromBuildingNumber = function (
   return datastreamIdMatched;
 };
 
+/**
+ * Create URL to fetch the details of single Datastream
+ * @param {String} baseUrl Base URL of the STA server
+ * @param {Number} datastreamID Integer representing the Datastream ID
+ * @returns {String} URL string for fetching a single Datastream
+ */
 export const getDatastreamUrl = function (baseUrl, datastreamID) {
   if (!datastreamID) return;
   const fullDatastreamURL = `${baseUrl}/Datastreams(${datastreamID})`;
@@ -88,10 +94,10 @@ export const getDatastreamUrl = function (baseUrl, datastreamID) {
 };
 
 /**
- * Create URL to fetch the Observations corresponding to a provided Datastream
+ * Create URL to fetch Observations
  * @param {String} baseUrl Base URL of the STA server
- * @param {Number} datastreamID - Integer representing the Datastream ID
- * @returns {String} URL string for fetching the Observations corresponding to a Datastream
+ * @param {Number} datastreamID Integer representing the Datastream ID
+ * @returns {String} URL string for fetching Observations
  */
 export const getObservationsUrl = function (baseUrl, datastreamID) {
   if (!datastreamID) return;
@@ -128,9 +134,9 @@ export const QUERY_PARAMS_COMBINED = {
 
 /**
  * Perform a GET request using the Axios library
- * @param {String} urlObservations A URL that fetches Observations from STA instance
+ * @param {String} urlObservations A URL that fetches Observations from an STA instance
  * @param {Object} urlParamObj The URL parameters to be sent together with the GET request
- * @returns {Promise} A promise that returns the first page of results
+ * @returns {Promise} A promise that contains the first page of results when fulfilled
  */
 export const axiosGetRequest = function (urlObservations, urlParamObj) {
   return axios.get(urlObservations, {
@@ -138,6 +144,12 @@ export const axiosGetRequest = function (urlObservations, urlParamObj) {
   });
 };
 
+/**
+ * Retrieve the metadata for a single datastream
+ * @async
+ * @param {String} urlDatastream A URL that fetches a Datastream from an STA instance
+ * @returns {Promise} A promise that contains a metadata object for a Datastream when fulfilled
+ */
 export const getDatastreamMetadata = async function (urlDatastream) {
   try {
     // Extract properties of interest
@@ -182,6 +194,7 @@ export const formatSTAResponseForHeatMap = function (obsArray) {
 /**
  * Draw a heatmap using Highcharts library
  * @param {Array} formattedObsArrayForHeatmap Response from SensorThings API formatted for use in a heatmap
+ * @param {Object} datastreamMetadata Object containing Datastream metadata
  * @returns {undefined} undefined
  */
 export const drawHeatMapHC = function (
@@ -299,13 +312,13 @@ export const formatSTAResponseForLineChart = function (obsArray) {
 /**
  * Draw a line chart using Highcharts library
  * @param {Array} formattedObsArrayForLineChart Response from SensorThings API formatted for use in a line chart
+ * @param {Object} datastreamMetadata Object containing Datastream metadata
  * @returns {undefined} undefined
  */
 export const drawLineChartHC = function (
   formattedObsArrayForLineChart,
   datastreamMetadata
 ) {
-  // Create the chart
   Highcharts.stockChart("chart-line", {
     chart: {
       zoomType: "x",
@@ -316,13 +329,13 @@ export const drawLineChartHC = function (
     },
 
     title: {
-      text: "Inlet flow (Vorlauf)",
+      // text: "Inlet flow (Vorlauf)",
       text: `${datastreamMetadata.description}`,
       "align": "left",
     },
 
     subtitle: {
-      text: "Temperature variation by hour in 2020",
+      // text: "Temperature variation by hour in 2020",
       text: `${datastreamMetadata.name}`,
       align: "left",
     },
@@ -398,15 +411,23 @@ export const getCombinedObservationsFromAllNextLinks = function (
     });
 };
 
+/**
+ * Retrieve the metadata for a Datastream as well as the Observations corresponding to it
+ * @async
+ * @param {Promise} metadataPlusObsPromiseArray An array that contains two promises, one for datastream metadata, the other for observations
+ * @returns {Promise} A promise that contains two arrays when fulfilled, one for datastream metadata and the other for observations
+ */
 export const getMetadataPlusObservationsForChart = async function (
-  promiseArray
+  metadataPlusObsPromiseArray
 ) {
+  // Array to store our final result
   const combinedResolvedPromises = [];
 
-  for (const promise of promiseArray) {
+  // Use for/of loop - we need to maintain the order of execution of the async operations
+  for (const promise of metadataPlusObsPromiseArray) {
     try {
+      // Resolved value of a single promise
       const resolvedPromise = await promise;
-
       combinedResolvedPromises.push(resolvedPromise);
     } catch (err) {
       console.log(err);
@@ -418,7 +439,7 @@ export const getMetadataPlusObservationsForChart = async function (
 /**
  * Retrieve all the Observations from an array of Observations promises
  * @async
- * @param {Promise} observationPromiseArray A promise that contains an array of observations when fulfilled
+ * @param {Promise} observationPromiseArray An array that contains N observation promises
  * @returns {Promise} A promise that contains an array of Observations from multiple Datastreams when fulfilled
  */
 const getObservationsFromMultipleDatastreams = async function (