First attempt at basic tag functionality.

public/js/tags.js

@@ -0,0 +1,115 @@
+$(function () {
+
+    /*
+     Hide and show the tag index help.
+     */
+    $('#tagHelp').on('show.bs.collapse', function () {
+        // set hideTagHelp = false
+        $.post('/tags/hideTagHelp/false', {_token: token});
+        $('#tagHelpButton').text('Hide help');
+
+    }).on('hide.bs.collapse', function () {
+        // set hideTagHelp = true
+        $.post('/tags/hideTagHelp/true', {_token: token});
+        $('#tagHelpButton').text('Show help');
+
+    });
+
+    $('#clearLocation').click(clearLocation);
+
+});
+
+/*
+ Some vars as prep for the map:
+ */
+var map;
+var markers = [];
+var setTag = false;
+
+var mapOptions = {
+    zoom: zoomLevel,
+    center: new google.maps.LatLng(latitude, longitude),
+    disableDefaultUI: true
+};
+
+/*
+ Clear location and reset zoomLevel.
+ */
+function clearLocation() {
+    "use strict";
+    deleteMarkers();
+    $('input[name="latitude"]').val("");
+    $('input[name="longitude"]').val("");
+    $('input[name="zoomLevel"]').val("6");
+    setTag = false;
+    $('input[name="setTag"]').val('false');
+    return false;
+}
+
+function initialize() {
+
+    /*
+    Create new map:
+     */
+    map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
+
+    /*
+    Respond to click event.
+     */
+    google.maps.event.addListener(map, 'rightclick', function (event) {
+        placeMarker(event);
+    });
+
+    /*
+    Respond to zoom event.
+     */
+    google.maps.event.addListener(map, 'zoom_changed', function () {
+        saveZoomLevel(event);
+    });
+    /*
+    Maybe place marker?
+     */
+    if(doPlaceMarker) {
+        var myLatlng = new google.maps.LatLng(latitude,longitude);
+        var fakeEvent = {};
+        fakeEvent.latLng = myLatlng;
+        placeMarker(fakeEvent);
+
+    }
+}
+
+/**
+ * save zoom level of map into hidden input.
+ */
+function saveZoomLevel() {
+    "use strict";
+    $('input[name="zoomLevel"]').val(map.getZoom());
+}
+
+/**
+ * Place marker on map.
+ * @param event
+ */
+function placeMarker(event) {
+    deleteMarkers();
+    var marker = new google.maps.Marker({position: event.latLng, map: map});
+    $('input[name="latitude"]').val(event.latLng.lat());
+    $('input[name="longitude"]').val(event.latLng.lng());
+    markers.push(marker);
+    setTag = true;
+    $('input[name="setTag"]').val('true');
+}
+
+
+/**
+ * Deletes all markers in the array by removing references to them.
+ */
+function deleteMarkers() {
+    for (var i = 0; i < markers.length; i++) {
+        markers[i].setMap(null);
+    }
+    markers = [];
+}
+
+
+google.maps.event.addDomListener(window, 'load', initialize);