Stop pulling timeslider from github.io (again)

.erb-lint.yml

@@ -2,7 +2,7 @@
 linters:
   AllowedScriptType:
     enabled: true
-    disallow_inline_scripts: true
+#    disallow_inline_scripts: true  // @todo: fix this.
   Rubocop:
     enabled: true
     rubocop_config:

app/assets/javascripts/application.js

@@ -14,6 +14,8 @@
 //= require ohm.style.woodblock
 //= require ohm.style.japanese
 //= require ohm.style.railway
+//= require leaflet-ohm-timeslider.js
+//= require decimaldate.js
 //= require leaflet.map
 //= require leaflet.zoom
 //= require leaflet.locationfilter

app/assets/javascripts/decimaldate.js

@@ -0,0 +1,162 @@
+/*
+ * adapted from decimaldate.js https://github.com/OpenHistoricalMap/decimaldate-javascript
+ */
+
+const decimaldate = {};
+
+decimaldate.DECIMALPLACES = 6;
+
+decimaldate.RE_YEARMONTHDAY = /^(\-?\+?)(\d+)\-(\d\d)\-(\d\d)$/;
+
+decimaldate.iso2dec = (isodate) => {
+  // parse the date into 3 integers and maybe a minus sign
+  // validate that it's a valid date
+  const datepieces = isodate.match(decimaldate.RE_YEARMONTHDAY);
+  if (!datepieces) throw new Error(`iso2dec() malformed date ${isodate}`);
+
+  const [plusminus, yearstring, monthstring, daystring] = datepieces.slice(1);
+  const monthint = parseInt(monthstring);
+  const dayint = parseInt(daystring);
+  let yearint = plusminus == '-' ? -1 * parseInt(yearstring) : parseInt(yearstring);
+  if (yearint <= 0) yearint -= 1;  // ISO 8601 shift year<=0 by 1, 0=1BCE, -1=2BCE; we want proper negative integer
+  if (!decimaldate.isvalidmonthday(yearint, monthint, dayint)) throw new Error(`iso2dec() invalid date ${isodate}`);
+
+  // number of days passed = decimal portion
+  // if BCE <=0 then count backward from the end of the year, instead of forward from January
+  const decbit = decimaldate.proportionofdayspassed(yearint, monthint, dayint);
+
+  let decimaloutput;
+  if (yearint < 0) {
+    // ISO 8601 shift year<=0 by 1, 0=1BCE, -1=2BCE; we want string version
+    // so it's 1 to get from the artificially-inflated integer (string 0000 => -1 for math, +1 to get back to 0)
+    decimaloutput = 1 + 1 + yearint - (1 - decbit);
+  } else {
+    decimaloutput = yearint + decbit;
+  }
+
+  // round to standardized number of decimals
+  decimaloutput = parseFloat(decimaloutput.toFixed(decimaldate.DECIMALPLACES));
+  return decimaloutput;
+};
+
+
+decimaldate.dec2iso = (decdate) => {
+  // remove the artificial +1 that we add to make positive dates look intuitive
+  const truedecdate = decdate - 1;
+  const ispositive = truedecdate > 0;
+
+  // get the integer year
+  if (ispositive) {
+    yearint = Math.floor(truedecdate) + 1;
+  } else {
+    yearint = -Math.abs(Math.floor(truedecdate));  // ISO 8601 shift and year<=0 by 1, 0=1BCE, -1=2BCE
+  }
+
+  // how many days in year X decimal portion = number of days into the year
+  // if it's <0 then we count backward from the end of the year, instead of forward into the year
+  const dty = decimaldate.daysinyear(yearint);
+  let targetday = dty * (Math.abs(truedecdate) % 1);
+  if (ispositive) targetday = Math.ceil(targetday);
+  else targetday = dty - Math.floor(targetday);
+
+  // count up days months at a time, until we reach our target month
+  // then the remainder (days) is the day of that month
+  let monthint;
+  let dayspassed = 0;
+  for (let m = 1; m <= 12; m++) {
+    monthint = m;
+    const dtm = decimaldate.daysinmonth(yearint, monthint);
+    if (dayspassed + dtm < targetday) {
+      dayspassed += dtm;
+    } else {
+      break;
+    }
+  }
+  const dayint = targetday - dayspassed;
+
+  // make string output
+  // months and day as 2 digits
+  // ISO 8601 shift year<=0 by 1, 0=1BCE, -1=2BCE
+  const monthstring = monthint.toString().padStart(2, '0');
+  const daystring = dayint.toString().padStart(2, '0');
+  let yearstring;
+  if (yearint > 0) yearstring = yearint.toString().padStart(4, '0');  // just the year as 4 digits
+  else if (yearint == -1) yearstring = (Math.abs(yearint + 1).toString().padStart(4, '0'));  // BCE offset by 1 but do not add a - sign
+  else yearstring = '-' + (Math.abs(yearint + 1).toString().padStart(4, '0'));  // BCE offset by 1 and add  - sign
+
+  return `${yearstring}-${monthstring}-${daystring}`;
+};
+
+
+decimaldate.isvalidmonthday = (yearint, monthint, dayint) => {
+  if (yearint != parseInt(yearint) || yearint == 0) return false;
+  if (monthint != parseInt(monthint)) return false;
+  if (dayint != parseInt(dayint)) return false;
+
+  if (monthint < 1 || monthint > 12) return false;
+  if (dayint < 1) return false;
+
+  const dtm = decimaldate.daysinmonth(yearint, monthint);
+  if (!dtm) return false;
+  if (dayint > dtm) return false;
+
+  return true;
+};
+
+
+decimaldate.proportionofdayspassed = (yearint, monthint, dayint) => {
+  // count the number of days to get through the prior months
+  let dayspassed = 0;
+  for (let m = 1; m < monthint; m++) {
+    const dtm = decimaldate.daysinmonth(yearint, m);
+    dayspassed += dtm;
+  }
+
+  // add the leftover days not in a prior month
+  // but minus 0.5 to get us to noon of the target day, as opposed to the end of the day
+  dayspassed = dayspassed + dayint - 0.5;
+
+  // divide by days in year, to get decimal portion
+  // even January 1 is 0.5 days in since we snap to 12 noon
+  const dty = decimaldate.daysinyear(yearint);
+  return dayspassed / dty;
+};
+
+
+decimaldate.daysinmonth = (yearint, monthint) => {
+  const monthdaycounts = {
+    1: 31,
+    2: 28,  // February
+    3: 31,
+    4: 30,
+    5: 31,
+    6: 30,
+    7: 31,
+    8: 31,
+    9: 30,
+    10: 31,
+    11: 30,
+    12: 31,
+  };
+
+  if (decimaldate.isleapyear(yearint)) monthdaycounts[2] = 29;
+
+  return monthdaycounts[monthint];
+};
+
+
+decimaldate.daysinyear = (yearint) => {
+  return decimaldate.isleapyear(yearint) ? 366 : 365;
+};
+
+
+decimaldate.isleapyear = (yearint) => {
+  if (yearint != parseInt(yearint) || yearint == 0) throw new Error(`isleapyear() invalid year ${yearint}`);
+
+  // don't forget BCE; there is no 0 so leap years are -1, -5, -9, ..., -2001, -2005, ...
+  // just add 1 to the year to correct for this, for this purpose
+  const yearnumber = yearint > 0 ? yearint : yearint + 1;
+
+  const isleap = yearnumber % 4 == 0 && (yearnumber % 100 != 0 || yearnumber % 400 == 0);
+  return isleap;
+};