From 2e269b8ec43c4f155f3d532513de9ef918bd8579 Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel@icaotix.de>
Date: Sun, 22 Nov 2020 00:05:53 +0100
Subject: [PATCH] Improve initial load performance project 2 aufgabe 3

---
 projects/project-2/aufgabe3.js | 38 ++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/projects/project-2/aufgabe3.js b/projects/project-2/aufgabe3.js
index 897da88..c03f7d0 100644
--- a/projects/project-2/aufgabe3.js
+++ b/projects/project-2/aufgabe3.js
@@ -1,23 +1,35 @@
 const aufgabe3 = async () => {
 
+    const years = [2015, 2016, 2017]
+
     const loadData = async () => {
-        const loadSeries = async (seriesCode, pageSize = 20) => {
-            const values = (await axios.get("https://unstats.un.org/SDGAPI/v1/sdg/Series/Data", {
-                params: {
-                    seriesCode: seriesCode,
-                    pageSize: pageSize
+        const loadSeries = async seriesCode => {
+            let maxNumberOfElements = (await axios.get("https://unstats.un.org/SDGAPI/v1/sdg/Series/Data", {
+                    params: {seriesCode}
                 }
-            })).data // getting axios data object
-            return values.data // getting api data object (remove paging information)
-                .filter(elem => elem.timePeriodStart >= 2015 && elem.timePeriodStart <= 2017)
-                .filter(elem => elem.dimensions.Location === "ALLAREA")
+            )).data.totalElements
+
+            let requests = []
+            for (let year of years) {
+                requests.push(axios.get("https://unstats.un.org/SDGAPI/v1/sdg/Series/Data", {
+                    params: {
+                        seriesCode: seriesCode,
+                        pageSize: maxNumberOfElements,
+                        timePeriod: year
+                    }
+                }))
+            }
+
+            let dataArrays = (await Promise.all(requests)).map(arr => arr.data.data)
+            const values = [].concat(...dataArrays)
+            return values.filter(elem => elem.dimensions.Location === "ALLAREA")
         }
 
         const apiData = await Promise.all([
-            loadSeries("SH_H2O_SAFE", 5000),
-            loadSeries("SH_SAN_SAFE", 5000)
+            loadSeries("SH_H2O_SAFE"),
+            loadSeries("SH_SAN_SAFE")
         ])
-        return [...apiData[0], ...apiData[1]]
+        return [].concat(...apiData)
     }
 
     const levels = [0, 50, 80, 85, 90, 95, 99, 100]
@@ -51,7 +63,7 @@ const aufgabe3 = async () => {
         minZoom: 1,
         maxZoom: 18
     }))
-    let [geojsonData, apiData] = await Promise.all([
+    const [geojsonData, apiData] = await Promise.all([
         $.getJSON('europe.geo.json'),
         loadData()
     ])