From 3bbc5cf524a771b0a2130e47b0fc969dcb35fb61 Mon Sep 17 00:00:00 2001
From: Kumar Saurav <mailkr.srv@gmail.com>
Date: Fri, 24 Jul 2020 19:25:01 +0530
Subject: [PATCH 1/2] Persist language change across browser refresh

---
 index.html          |   2 +
 media/js/persist.js | 192 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 194 insertions(+)
 create mode 100644 media/js/persist.js

diff --git a/index.html b/index.html
index 46ec04c..325ad53 100644
--- a/index.html
+++ b/index.html
@@ -11,11 +11,13 @@
   <script src="media/js/jquery-1.11.2.min.js"></script>
   <script src="media/js/foopy.js"></script>
   <script src="media/js/l10n.js"></script>
+  <script src="media/js/persist.js"></script>
   <!-- #responses div elements has display:none by default in case if js is disabled -->
   <script>
     $(document).ready(function() {
         $('#responses div').show();
     });
+    $('#lang').persist('attributes', 'selected')
   </script>
   <!-- end of manipulation if js is disabled -->
   <script>
diff --git a/media/js/persist.js b/media/js/persist.js
new file mode 100644
index 0000000..1433bdd
--- /dev/null
+++ b/media/js/persist.js
@@ -0,0 +1,192 @@
+// Licensed under Apache License, Version 2.0
+// which is compatible with MPL V2.0
+
++function (factory) {
+  if (typeof define === 'function' && define.amd) {
+    define('adcom/persist', ['jquery'], factory)
+  } else {
+    factory(window.jQuery)
+  }
+}(function ($) {
+  'use strict';
+
+  // PERSIST CLASS DEFINITION
+  // ========================
+  var Persist = function (element, options) {
+    this.options = options
+    this.$element = $(element)
+
+    this.$key = this.options.key || this.$element.attr('id')
+
+    this.observations = {}
+    this.filters = {}
+  }
+
+  Persist.VERSION = '0.1.1'
+
+  // These are meant to mirror MutationObserver options, plus some extras
+  Persist.DEFAULTS = {
+    key: null
+  }
+
+  Persist.prototype.attributes = function (attributes, filter) {
+    var $this = this
+    attributes = (typeof attributes == 'string') ? attributes.split(/[,\s]+/) : attributes
+    filter = (typeof filter == 'string') ? filter.split(/[,\s]+/) : filter
+
+    attributes.forEach(function(attr) {
+      var key = { element: $this.$key, type: 'attributes', path: attr }
+      $this.filters[key] = filter
+
+      var ev = $.Event('add.ac.persist', { key: key })
+      $this.$element.trigger(ev)
+      if (ev.isDefaultPrevented()) return
+
+      var observer = new MutationObserver(function (mutations) {
+        mutations.forEach(function (mutation) {
+          // Extend the mutation object with additional properties
+          // Allows user event to change the persisted value if desired
+
+          var value = $this.$element[0].getAttribute(attr)
+
+          // if filters are turned on, filter out any attributes not in the
+          // filter list for storage.
+          if (filter) {
+            value = $.unique($.grep(value.split(/[,\s]+/), function (item) { return filter.indexOf(item) > -1 })).join(' ')
+          }
+
+          // Change is persisted by hooking into the mutation event.
+          // var ev = $.Event('mutation.ac.persist', $.extend({}, key, { mutation: mutation }))
+          var ev = $.Event('mutation.ac.persist', { key: key, mutation: mutation, value: value })
+          $this.$element.trigger(ev)
+        })
+      })
+
+      var ev = $.Event('added.ac.persist', { key: key })
+      $this.$element.trigger(ev)
+
+      // Don't add mutation until after added, so we don't count initialization mutation...
+      var options = $.extend({}, $this.options, { attributes: true, attributeFilter: [attr] })
+      observer.observe($this.$element[0], options)
+
+      // Remove old observer at this key
+      if ($this.observations[key]) $this.observations[key].disconnect()
+      $this.observations[key] = observer
+    })
+  }
+  Persist.prototype.attribute = Persist.prototype.attributes
+
+  function getPath (parent, child, path) {
+    path = path || []
+    if (parent.childNodes.length == 0 && parent != child) return false
+    if (parent == child) return true
+
+    for (var i = 0; i < parent.childNodes.length; i++) {
+      var descendent = parent.childNodes[i]
+      if (getPath(descendent, child, path) !== false) {
+        path.unshift(i)
+        return path
+      }
+    }
+  }
+
+  Persist.prototype.characterData = function () {
+    var $this = this
+    var key = { element: this.$key, type: 'characterData' }
+
+    var ev = $.Event('add.ac.persist', { key: key })
+    this.$element.trigger(ev)
+    if (ev.isDefaultPrevented()) return
+
+    var observer = new MutationObserver(function (mutations) {
+      mutations.forEach(function (mutation) {
+        var path = getPath($this.$element[0], mutation.target)
+
+        var value = mutation.target.data
+
+        var ev = $.Event('mutation.ac.persist', {
+          mutation: mutation,
+          value: value,
+          key: $.extend({path: path.join('.')}, key)
+        })
+        $this.$element.trigger(ev)
+      })
+    })
+
+    // How to get all separate records underneat this one..
+    var ev = $.Event('added.ac.persist', { key: key })
+    this.$element.trigger(ev)
+
+    // Don't add mutation until after added, so we don't count initialization mutation...
+    var options = $.extend({}, this.options, { characterData: true, subtree: true })
+    observer.observe($this.$element[0], options)
+
+    // Remove old observer at this key
+    if ($this.observations[key]) $this.observations[key].disconnect()
+    $this.observations[key] = observer
+  }
+
+  Persist.prototype.update = function (key, value) {
+    switch (key.type) {
+      case "attributes":
+        var filter = this.filters[key]
+        if (filter) {
+          var currentValues = this.$element[0].getAttribute(key.path).split(/[,\s]+/)
+          var storedValues = value.split(/[,\s]+/)
+
+          var newValues = $.grep(currentValues, function (item) { return filter.indexOf(item) < 0 })
+          newValues = $.unique($.merge(newValues, storedValues))
+          value = newValues.join(' ')
+        }
+        this.$element.attr(key.path, value)
+        break;
+
+      case "characterData":
+        var node = this.$element[0]
+        key.path.split('.').forEach(function(idx) {
+          node = node.childNodes[idx]
+        })
+        window.node = node
+        node.replaceData(0, node.length, value)
+        break;
+
+      // case "childList":
+      //   break;
+    }
+  }
+
+
+  // PERSIST PLUGIN DEFINITION
+  // =========================
+
+  function Plugin(option) {
+    var args = Array.prototype.slice.call(arguments, Plugin.length)
+    return this.each(function () {
+      var $this = $(this)
+      var data  = $this.data('ac.persist')
+
+      // Reset if we call the constructor again with options
+      if (typeof option == 'object' && option && data) data = false
+
+      var options = $.extend({}, Persist.DEFAULTS, $this.data(), data && data.options, typeof option == 'object' && option)
+
+      if (!data) $this.data('ac.persist', (data = new Persist(this, options)))
+      if (typeof option == 'string') data[option].apply(data, args)
+    })
+  }
+
+  var old = $.fn.persist
+
+  $.fn.persist             = Plugin
+  $.fn.persist.Constructor = Persist
+
+  // PERSIST NO CONFLICT
+  // ===================
+
+  $.fn.persist.noConflict = function () {
+    $.fn.persist = old
+    return this
+  }
+
+  return Persist
+});

From 3413c36047fb3e62dc4c3a49f8773e6d06dda8eb Mon Sep 17 00:00:00 2001
From: Kumar Saurav <mailkr.srv@gmail.com>
Date: Fri, 24 Jul 2020 19:29:14 +0530
Subject: [PATCH 2/2] Added citation

---
 media/js/persist.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/media/js/persist.js b/media/js/persist.js
index 1433bdd..5265fcb 100644
--- a/media/js/persist.js
+++ b/media/js/persist.js
@@ -1,5 +1,6 @@
 // Licensed under Apache License, Version 2.0
 // which is compatible with MPL V2.0
+// sourced from https://newsdev.github.io/adcom/persist-js.html
 
 +function (factory) {
   if (typeof define === 'function' && define.amd) {