From 8ee34368d8cd817e4fd10c701999d247f053988c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20B=C3=B6sch-Plepelits?= <skunk@xover.mud.at>
Date: Fri, 3 Aug 2018 21:36:05 +0200
Subject: [PATCH] twig: new filter 'md5'

---
 doc/TwigJS.md        |  1 +
 package.json         |  1 +
 src/twigFunctions.js | 10 ++++++++++
 3 files changed, 12 insertions(+)

diff --git a/doc/TwigJS.md b/doc/TwigJS.md
index 6dd4b19c..68eb03c5 100644
--- a/doc/TwigJS.md
+++ b/doc/TwigJS.md
@@ -67,6 +67,7 @@ Extra filters:
 * filter `osmDateParse`: returns an array with the lower and upper boundary of the year of a `start_date` tag. See [https://github.com/plepe/openstreetmap-date-parser](openstreetmap-date-parser) for details.
 * filter `natsort`: Sort an array naturally, see [https://www.npmjs.com/package/natsort](natsort) for details.
 * filter `unique`: Remove duplicate elements from an array.
+* filter `md5`: calculate md5 hash of a string.
 
 Notes:
 * Variables will automatically be HTML escaped, if not the filter raw is used, e.g.: {{ tags.name|raw }}
diff --git a/package.json b/package.json
index 1df6530e..cbfa4e9f 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
     "leaflet-textpath": "https://github.com/makinacorpus/Leaflet.TextPath#leaflet0.8-dev",
     "leaflet.locatecontrol": "^0.61.0",
     "leaflet.polylinemeasure": "https://github.com/ppete2/Leaflet.PolylineMeasure.git",
+    "md5": "^2.2.1",
     "modulekit-tabs": "^0.1.0",
     "moment": "^2.18.1",
     "natsort": "^1.0.6",
diff --git a/src/twigFunctions.js b/src/twigFunctions.js
index 134091cd..a19b02f0 100644
--- a/src/twigFunctions.js
+++ b/src/twigFunctions.js
@@ -3,6 +3,9 @@ var OpeningHours = require('opening_hours')
 var colorInterpolate = require('color-interpolate')
 var osmParseDate = require('openstreetmap-date-parser')
 const natsort = require('natsort')
+const md5 = require('md5')
+
+var md5cache = {}
 
 OverpassLayer.twig.extendFunction('tagsPrefix', function (tags, prefix) {
   var ret = {}
@@ -59,6 +62,13 @@ OverpassLayer.twig.extendFunction('colorInterpolate', function (map, value) {
 OverpassLayer.twig.extendFilter('osmParseDate', function (value) {
   return osmParseDate(value)
 })
+OverpassLayer.twig.extendFilter('md5', function (value) {
+  if (value in md5cache) {
+    return md5cache[value]
+  }
+
+  return md5cache[value] = md5(value)
+})
 OverpassLayer.twig.extendFunction('evaluate', function (tags) {
   var ob = {
     id: 'x0',