Add estimated map location based on other posts

Remove the default map location, and instead base it on the location
of existing posts.

Ref: #121

README.md

@@ -11,3 +11,4 @@ The user manual is at [twyne.readthedocs.io](https://twyne.readthedocs.io/).
 ## Attribution
 
 * [assets/img/feed-icon.png](https://commons.wikimedia.org/wiki/File:Feed-icon.svg) Originally distributed by the Mozilla Foundation under a MPL/GPL/LGPL tri-license.
+* [Feather Icons](https://feathericons.com), MIT license.

assets/js/map.js

@@ -49,7 +49,7 @@ function moveMap () {
 
 // Marker.
 let marker = null;
-let defaultView = [-32.054178, 115.7475];
+let defaultView = [0, 0];
 const mapData = document.getElementById('map').dataset;
 if (mapData && mapData.latitude && mapData.longitude) {
     defaultView = new L.LatLng(mapData.latitude, mapData.longitude);
@@ -92,15 +92,47 @@ map.on('click', clickEvent => {
     moveMarker(clickEvent.latlng);
 });
 
+const dateInput = document.querySelector('input[name="date"]');
+let estimatedMarker = null;
+dateInput.addEventListener('change', (event) => {
+    setEstimatedLocation(event.target.value);
+});
+setEstimatedLocation(dateInput.value);
+
+function setEstimatedLocation (date) {
+    // eslint-disable-next-line no-undef
+    const geojsonUrl = appBaseUrl + 'map/estimates.json?date=' + date;
+    const dataRequest = new XMLHttpRequest();
+    dataRequest.addEventListener('load', function () {
+        const data = JSON.parse(this.responseText);
+        const estimatedLatLng = [data.lat, data.lng];
+        if (estimatedMarker === null) {
+            estimatedMarker = new L.Marker(estimatedLatLng, {
+                icon: getIcon('send', [23, 23], [23, 0])
+            });
+            map.addLayer(estimatedMarker);
+        } else {
+            estimatedMarker.setLatLng(estimatedLatLng);
+        }
+        map.setView(estimatedLatLng, 12);
+    });
+    dataRequest.open('GET', geojsonUrl);
+    dataRequest.send();
+}
+
+function getIcon (name, size, anchor) {
+    return L.icon({
+        iconUrl: '/build/images/' + name + '.png',
+        iconRetinaUrl: '/build/images/' + name + '-2x.png',
+        iconSize: size,
+        iconAnchor: anchor
+    });
+}
+
 function makeMarker (latLng) {
     marker = new L.Marker(latLng, {
         draggable: mapData.edit,
-        icon: L.icon({
-            iconUrl: '/build/images/map-pin.png',
-            iconRetinaUrl: '/build/images/map-pin-2x.png',
-            iconSize: [20, 24],
-            iconAnchor: [10, 24]
-        })
+        icon: getIcon('map-pin', [20, 24], [10, 24])
     });
     map.addLayer(marker);
     marker.on('dragend', dragEvent => {

package.json

@@ -2,24 +2,24 @@
     "license": "GPL-3.0-or-later",
     "private": true,
     "devDependencies": {
-        "@symfony/webpack-encore": "^1.7.0",
-        "codemirror": "^5.65.0",
-        "core-js": "^3.20.2",
+        "@symfony/webpack-encore": "^1.8.2",
+        "codemirror": "^5.65.9",
+        "core-js": "^3.26.0",
         "eslint": "^7.32.0",
         "eslint-config-standard": "^16.0.3",
-        "eslint-plugin-import": "^2.25.3",
+        "eslint-plugin-import": "^2.26.0",
         "eslint-plugin-node": "^11.1.0",
         "eslint-plugin-promise": "^5.2.0",
         "eslint-plugin-standard": "^5.0.0",
         "file-loader": "^6.2.0",
-        "jquery": "^3.6.0",
-        "leaflet": "^1.7.1",
-        "less": "^4.1.2",
+        "jquery": "^3.6.1",
+        "leaflet": "^1.9.2",
+        "less": "^4.1.3",
         "less-loader": "^8.1.1",
         "normalize.css": "^8.0.1",
-        "postcss": "^8.4.5",
+        "postcss": "^8.4.19",
         "postcss-loader": "^5.3.0",
-        "regenerator-runtime": "^0.13.9",
+        "regenerator-runtime": "^0.13.10",
         "select2": "^4.0.13",
         "stylelint": "^13.13.1",
         "stylelint-config-standard": "^22.0.0",

public/build/805.3e825de1.js.LICENSE.txt

@@ -0,0 +1,4 @@
+/* @preserve
+ * Leaflet 1.9.2, a JS library for interactive maps. https://leafletjs.com
+ * (c) 2010-2022 Vladimir Agafonkin, (c) 2010-2011 CloudMade
+ */