Move the time slider to a Nominatim search result's date

app/assets/javascripts/index.js

@@ -9,6 +9,7 @@
 //= require leaflet.share
 //= require leaflet.query
 //= require index/contextmenu
+//= require index/date_utils
 //= require index/search
 //= require index/layers/data
 //= require index/export

app/assets/javascripts/index/date_utils.js

@@ -0,0 +1,60 @@
+// Shared date helpers for the map UI, kept in one place so query.js and
+// search.js do not each carry their own copy.
+OSM.Date = {
+  // Compare ISO 8601 dates correctly (handles BCE dates where string comparison fails)
+  compareDates: function (date1, date2) {
+    if (!date1 && !date2) return 0;
+    if (!date1) return -1;
+    if (!date2) return 1;
+
+    const match1 = date1.match(/^(-?\d+)(?:-(\d{1,2}))?(?:-(\d{1,2}))?/);
+    const match2 = date2.match(/^(-?\d+)(?:-(\d{1,2}))?(?:-(\d{1,2}))?/);
+    if (!match1 || !match2) return date1.localeCompare(date2);
+
+    const [, year1Str, month1Str, day1Str] = match1;
+    const [, year2Str, month2Str, day2Str] = match2;
+    const year1Int = parseInt(year1Str, 10);
+    const year2Int = parseInt(year2Str, 10);
+
+    if (year1Int !== year2Int) return year1Int - year2Int;
+
+    const month1 = month1Str ? parseInt(month1Str, 10) : 1;
+    const month2 = month2Str ? parseInt(month2Str, 10) : 1;
+    if (month1 !== month2) return month1 - month2;
+
+    const day1 = day1Str ? parseInt(day1Str, 10) : 1;
+    const day2 = day2Str ? parseInt(day2Str, 10) : 1;
+    return day1 - day2;
+  },
+
+  // Days in a month, accounting for leap years (BCE has no year 0).
+  daysInMonth: function (year, month) {
+    if (month !== 2) return [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month - 1];
+    const y = year > 0 ? year : year + 1;
+    const leap = y % 4 === 0 && (y % 100 !== 0 || y % 400 === 0);
+    return leap ? 29 : 28;
+  },
+
+  // Fill a partial date to a full YYYY-MM-DD, at the start or end of its period.
+  padDate: function (value, startend) {
+    if (value === null || value === undefined || value === "") return null;
+    const date = String(value).trim().replace(/^\+/, "");
+    if (/^-?\d+-\d\d-\d\d$/.test(date)) return date;
+    const yearMonth = date.match(/^(-?\d+)-(\d\d)$/);
+    if (yearMonth) {
+      if (startend === "start") return `${date}-01`;
+      const lastDay = OSM.Date.daysInMonth(parseInt(yearMonth[1], 10), parseInt(yearMonth[2], 10));
+      return `${date}-${String(lastDay).padStart(2, "0")}`;
+    }
+    if (/^-?\d+$/.test(date)) return startend === "start" ? `${date}-01-01` : `${date}-12-31`;
+    return null;
+  },
+
+  // True when a feature with these dates exists at the given time. The end date
+  // pads to the last day of its period, so a feature ending in 1700 lasts all year.
+  existsAt: function (startDate, endDate, atDate) {
+    const afterStart = !startDate || OSM.Date.compareDates(OSM.Date.padDate(startDate, "start"), atDate) <= 0;
+    const beforeEnd = !endDate || OSM.Date.compareDates(OSM.Date.padDate(endDate, "end"), atDate) > 0;
+    return afterStart && beforeEnd;
+  }
+};

app/assets/javascripts/index/query.js

@@ -320,41 +320,11 @@ OSM.Query = function (map) {
     return match ? parseInt(match[1], 10) < 1000 : false;
   }
 
-  // Compare ISO 8601 dates correctly (handles BCE dates where string comparison fails)
-  function compareDates(date1, date2) {
-    if (!date1 && !date2) return 0;
-    if (!date1) return -1;
-    if (!date2) return 1;
-
-    const match1 = date1.match(/^(-?\d+)(?:-(\d{1,2}))?(?:-(\d{1,2}))?/);
-    const match2 = date2.match(/^(-?\d+)(?:-(\d{1,2}))?(?:-(\d{1,2}))?/);
-    if (!match1 || !match2) return date1.localeCompare(date2);
-
-    const [, year1Str, month1Str, day1Str] = match1;
-    const [, year2Str, month2Str, day2Str] = match2;
-    const year1Int = parseInt(year1Str, 10);
-    const year2Int = parseInt(year2Str, 10);
-
-    if (year1Int !== year2Int) return year1Int - year2Int;
-
-    const month1 = month1Str ? parseInt(month1Str, 10) : 1;
-    const month2 = month2Str ? parseInt(month2Str, 10) : 1;
-    if (month1 !== month2) return month1 - month2;
-
-    const day1 = day1Str ? parseInt(day1Str, 10) : 1;
-    const day2 = day2Str ? parseInt(day2Str, 10) : 1;
-    return day1 - day2;
-  }
-
   function filterByDate(elements, currentDate) {
     if (!currentDate) return elements;
     return elements.filter(element => {
       const tags = element.tags || {};
-      const startDate = tags.start_date;
-      const endDate = tags.end_date;
-      if (startDate && compareDates(startDate, currentDate) > 0) return false;
-      if (endDate && compareDates(endDate, currentDate) <= 0) return false;
-      return true;
+      return OSM.Date.existsAt(tags.start_date, tags.end_date, currentDate);
     });
   }
 

app/assets/javascripts/index/search.js

@@ -91,10 +91,25 @@ OSM.Search = function (map) {
     }
   }
 
+  // Move the slider so the picked feature is visible. If it already exists at the
+  // current time we leave the slider alone.
+  function adjustTimeSliderToResult(data) {
+    if (!map.timeslider) return;
+    if (!data.startDate && !data.endDate) return;
+
+    // leave the slider alone if the feature already exists at the current time
+    if (OSM.Date.existsAt(data.startDate, data.endDate, map.timeslider.getDate())) return;
+
+    // out of view: jump to start_date, or to end_date when there is no start
+    const target = OSM.Date.padDate(data.startDate || data.endDate, "start");
+    if (target) map.timeslider.setDate(target);
+  }
+
   function clickSearchResult(e) {
     const data = $(this).data();
 
     panToSearchResult(data);
+    adjustTimeSliderToResult(data);
 
     // Let clicks to object browser links propagate.
     if (data.type && data.id) return;

app/controllers/searches/nominatim_queries_controller.rb

@@ -74,6 +74,7 @@ def create
                       :min_lat => min_lat, :max_lat => max_lat,
                       :min_lon => min_lon, :max_lon => max_lon,
                       :prefix => prefix, :name => name, :suffix => suffix,
+                      :start_date => start_date, :end_date => end_date,
                       :type => object_type, :id => object_id)
       end
     rescue StandardError => e