Bing Maps Api clear a layer - javascript

I have a page that works well it loads a Bing Map and creates a layer which is then filled with Polygons. I then need to reload the JSON data that makes the polygons and this again works, however the data is then added to another layer so appears over the top. I have tried to delete the layer, clear the layer etc etc but nothing seems to work.
Any idea please.
This is the function that does it all...
function AddData() {
dataLayer = new Microsoft.Maps.Layer();
Microsoft.Maps.loadModule('Microsoft.Maps.GeoJson', function () {
var featureCollection = Microsoft.Maps.GeoJson.read(json, {
polygonOptions: {
strokeColor: 'LightSkyBlue',
strokeThickness: 2
}
});
for (var i = 0; i < featureCollection.length; i++) {
var fillColour = featureCollection[i].metadata.FillColor;
featureCollection[i].setOptions({ fillColor: fillColour });
Microsoft.Maps.Events.addHandler(featureCollection[i], 'click', displayClickBox);
Microsoft.Maps.Events.addHandler(featureCollection[i], 'mouseover', displayMouseOverBox);
Microsoft.Maps.Events.addHandler(featureCollection[i],'mouseout', displayMouseOut);
dataLayer.add(featureCollection[i], 0);
}
map.layers.insert(dataLayer);
});
}
var getJson = function () {
var onContentComplete = function (response) {
//Load the JSON data into the local variable for use latter in the project...
json = response.data;
//load the map now that we have the polygon data...
AddData();
};
var onError = function (reason) {
//An error has occured so display a message to the user...
$scope.error = "Server communication error please try again...";
//Log the error to the console for admin debug...
console.log(reason.data);
};
//Load the JSON for the map polygons into memory ready for display...
$http.get("../JSON/MapData.json")
.then(onContentComplete, onError);
}
As I have said I have tried to clear the layer first using
dataLayer.clear();
But that seems to do nothing.
Help please as I have been working at this for hours now.
Thanks
Cliff.

By the sounds of things you want all data to render in a single layer, but instead it is rendering two or more layers. This happens because you are creating a new instance of dataLayer every time the AddData function is called. Additionally, this overwrites the local variable for dataLayer and thus you lose the reference to the original layer that you are trying to clear/delete. If you want to clear or delete the layer, do that before initializing the new layer. Try adding the following to the top of your AddData function:
if(dataLayer){
map.layers.remove(dataLayer);
}
Alternatively, reuse the layer by clearing it if it exists of or creating it if it doesn't:
if(dataLayer){
dataLayer.clear();
}else{
dataLayer = new Microsoft.Maps.Layer();
}

Related

Toggle GeoJSON layer in leaflet sidebar

How can I toggle the GeoJSON layers in my leaflet map as I would the L.marker layers?
https://jsfiddle.net/mawr35vj/
Please pardon me if this is a simple question, I'm still new to leaflet and have spent all day on this.
Here is the GeoJSON I would like toggled in the sidebar.
fetch('https://data.cityofnewyork.us/resource/ek5y-zcyf.geojson?$where=latitude is not null')
.then(function (response) {
// Read data as JSON
return response.json();
})
.then(function (data2) {
// Create the Leaflet layer for the data
var complaintLayer = L.geoJson(data2, {
// We make the points circles instead of markers so we can style them
pointToLayer: function (geoJsonPoint, latlng) {
return L.circleMarker(latlng);
},
// Then we can style them as we would other features
style: function (geoJsonFeature) {
return {
fillColor: '#0000ff',
radius: 6,
fillOpacity: 0.7,
stroke: false
};
}
});
});
-I tried assigning it a "var"
-I tried adding "complaintLayer" in the overlays as I did with the L.marker
-And many other various things that I can't remember but is obviously not working...
Update:
I'm trying to load the GeoJSON and assign it a variable, but having difficulty. I'm looking at this and related threads: How can I assign the contents of a geojson file to a variable in Javascript?
I got it to work if I just copy and paste the GeoJSON into the script, but having difficulty if I want to load it from a local file or API.
You can put complaintLayer in an array for a marker control, but the variable must be in the right scope - from the code you've posted it looks like it's local to the function it's populated in, so it won't be visible outside.
Per peeebeee's suggestion, I fixed the issue by loading the data and putting them into a "promise."
you can see a working example below:
https://jsfiddle.net/4x3sk1va/
Example of a promise below (taken from https://glitch.com/#ebrelsford)
// Fetch collisions data from our Glitch project
var collisionsFetch = fetch('https://cdn.glitch.com/03830164-a70e-47de-a9a1-ad757904d618%2Fpratt-collisions.geojson?1538625759015')
.then(function (response) {
// Read data as JSON
return response.json();
});
// Fetch lanes data from our Glitch project
var lanesFetch = fetch('https://cdn.glitch.com/fcedf615-7fef-4396-aa74-2e03fc324d71%2Fpratt-bike-routes.geojson?1538628711035')
.then(function (response) {
// Read data as JSON
return response.json();
});
// Once both have loaded, do some work with them
Promise.all([collisionsFetch, lanesFetch])
.then(function (fetchedData) {
console.log('Both datasets have loaded');
// Unpack the data from the Promise
var collisionsData = fetchedData[0];
var laneData = fetchedData[1];
// Add data in the order you want--first goes on the bottom
L.geoJson(collisionsData).addTo(map);
L.geoJson(laneData).addTo(map);
});

Creating MapKit JS with origin, destination and waypoints

I'm migrating from Google Maps API to Apple MapKit JS for the simple reason I have a developer account with them and they offer more free hits.
Anyway, actual examples of MapKit JS are a bit thin (or at least Google isn't finding them - draw what conspiracy theories you will), so although I've got the basics going of displaying an embeded map, I can't seem to do the next step which is route between two points (Apple's documentation also seems impenetrable as they don't show examples).
Here's my script for a basic map:
<script>
mapkit.init({
authorizationCallback: function(done) {
done('[MY-TOKEN]');
}
});
var MarkerAnnotation = mapkit.MarkerAnnotation
var myMarker = new mapkit.Coordinate(55.9496320, -3.1866360)
var myRegion = new mapkit.CoordinateRegion(
new mapkit.Coordinate(55.9496320, -3.1866360),
new mapkit.CoordinateSpan(0.003, 0.003)
);
var map = new mapkit.Map("map");
var myAnnotation = new MarkerAnnotation(myMarker, { color: "#9b6bcc", title: "theSpace On The Mile"});
map.showItems([myAnnotation]);
map.region = myRegion;
</script>
Now I want to:
• Show a walking route between two points
• Include waypoints on the route
Could someone show the code that would achieve this? Once I can see an example I know I'll get it ;-)
Ok, so I've found a solution to this so sharing it here for the benefit of others.
Let's start by saying Apple's MapKit JS doesn't appear to have a waypoints option as offered by Google Maps API - so the way around that is to create a map that stores the markers in an array and then routes from one to the next. The code stores the location of the last waypoint in a variable, and doesn't bother to draw a route to the last waypoint if this is the first one in the array (obviously).
<script>
// Initiallise MapKit - you'll need your own long-lived token for this
mapkit.init({
authorizationCallback: function(done) {
done('[MY-TOKEN]');
}
});
// Function to draw the route once MapKit has returned a response
function directionHandler(error, data) {
data["routes"].forEach(function(route, routeIdx) {
if (routeIdx !== 0) { return; }
overlays = [];
route['path'].forEach(function(path) {
// This styles the line drawn on the map
let overlayStyle = new mapkit.Style({
lineWidth: 3,
strokeColor: "#9b6bcc"
});
let overlay = new mapkit.PolylineOverlay(path, {
style: overlayStyle
});
overlays.push(overlay);
});
map.addOverlays(overlays);
});
}
// This asks MapKit for directions and when it gets a response sends it to directionHandler
function computeDirections(origin,destination) {
let directionsOptions = {
origin: origin,
destination: destination,
transportType: mapkit.Directions.Transport.Walking
};
directions.route(directionsOptions, directionHandler);
}
// This sets the initial region, but is overridden when all points have been potted to automatically set the bounds
var myRegion = new mapkit.CoordinateRegion(
new mapkit.Coordinate(55.9496320, -3.1866360),
new mapkit.CoordinateSpan(0.05, 0.05)
);
var map = new mapkit.Map("map");
map.region = myRegion;
var myAnnotations = [];
// lastWaypoint variable is 'unset' initially so the map doesn't try and find a route to the lastWaypoint for the first point of the route
var lastWaypoint = "unset";
var directions = new mapkit.Directions();
// Array of co-ordinates and label for marker
waypoints = [
{name:'Sofi’s Bar',lat:55.9746308,lon:-3.1722282},
{name:'TThe Roseleaf Cafe',lat:55.975992,lon:-3.173474},
{name:'Hemingway’s',lat:55.9763631,lon:-3.1706564},
{name:'Teuchter’s Landing',lat:55.9774693,lon:-3.1713826},
{name:'The King’s Wark',lat:55.9761425,lon:-3.1695419},
{name:'Malt and Hops',lat:55.975885,lon:-3.1698957},
{name:'The Carrier’s Quarters',lat:55.9760813,lon:-3.1685323},
{name:'Noble’s',lat:55.974905,lon:-3.16714},
{name:'The Fly Half',lat:55.9747906,lon:-3.1674496},
{name:'Port O’ Leith',lat:55.974596,lon:-3.167525}
];
// Loop through the array and create marker for each
waypoints.forEach(function(data) {
var myAnnotation = new mapkit.MarkerAnnotation(new mapkit.Coordinate(data['lat'],data['lon']), {
color: "#9b6bcc",
title: data['name']
});
myAnnotations.push(myAnnotation);
// As long as this isn't the first point on the route, draw a route back to the last point
if(lastWaypoint!="unset") {
computeDirections(lastWaypoint,new mapkit.Coordinate(data['lat'],data['lon']));
}
lastWaypoint = new mapkit.Coordinate(data['lat'],data['lon']);
});
map.showItems(myAnnotations);
</script>
This map is for a pub crawl around Leith, so the trasportType is 'Walking', but change that to 'Automobile' if you so wish.
With credit to Vasile whose MapKit JS Demo (https://github.com/vasile/mapkit-js-demo) helped me understand a lot more about the options.

Meteor : autorun won't make my code dynamic

I'm working hard on a meteor App which goal is to dynamically display on a google map the path of a vehicle, for example a boat on the sea.
Now, I see this library called gmaps.js, and since it is available on npm (just like google maps api) I decide to use this as a solution to draw of the map.
So, I have one page that add a geographic position (/runs/send) in the database each time I click on a button (this is enougth for testing). Then, on my other page (/runs/show) the goal is to get that data from mongo and prompt it dynamically on the map (meaning, if I add data by pressing the button, I'll see the new path appear on the map). Here is what the code looks like for now :
import { Template } from 'meteor/templating';
import {Tracker} from 'meteor/tracker';
import { Meteor } from 'meteor/meteor'
import gmaps from 'gmaps';
import google_maps from 'google-maps';
import {Mongo} from 'meteor/mongo';
import {Run} from './run.js';
import './methods.js';
Template.runs_show.helpers({
all() {
return Run.find({});
}
});
Template.runs_show.onCreated(function() {
var self = this;
self.autorun(function() {
self.subscribe('allRuns',function() {
google_maps.KEY = "MY API KEY";
google_maps.load(function(google){
console.log("Google Maps loaded");
// this creates a new map
var map = new gmaps({
el: '#map-gmaps',
lat: -12.043333,
lng: -77.028333
});
// for now , the data is on the run with {"maxSpeed" : "75"}
var dada = Run.findOne({"maxSpeed" : "75"});
// path look like [[x1,y1],[x2,y2]]
var path = dada.positions;
// this draws a red line on the map following the points defined in path
map.drawPolyline({
path: path,
strokeColor: '#FC291C',
strokeOpacity: 0.85,
strokeWeight: 6
});
});
});
});
});
So, as you can see, I put my onCreated function in a autorun block, and the data i'm using is from a database, so it's a cursor, so it should be reactive as well.
With a reactive data, inside a reactive block of code (thanks autorun)? expected to see a new line appear on my screen when I press "send" in my second page (this page just add a new set of [x,y] to the run.positions), but.... Nothing ! In fact, If I reload the page manually, the new line appears, of course, but wellll... That's not what I wanted to be honest...
So that's it! any idea what is missing in order to have some true reactivity?
EDIT :
This code works partially : the first time I load the page, the console.log(map) gives a undefined, but I just need to reload once, and then the page will work exactly as intended, showing what I want dynamically. However, one single code reload, and then, again, the console.log(map) gives undefined, and I need a new F5.... Any idea on why it does that / how to solve it?
Template.runs_show.onCreated(function() {
google_maps.KEY = "MY API KEY";
google_maps.load(function(google){
var map = new gmaps({
el: '#map-gmaps',
lat: -12.043333,
lng: -77.028333
});
// with that, I can use the map in the onRendered
Template.runs_show.map = map;
});
console.log(Template.runs_show);
});
Template.runs_show.onRendered(function() {
var self = this;
self.autorun(function() {
self.subscribe('allRuns',function() {
Tracker.autorun(function(){
var map = Template.runs_show.map;
console.log(map);
var dada = Run.findOne({"maxSpeed" : "75"});
var path = dada.positions;
map.drawPolyline({
path: path,
strokeColor: '#FC291C',
strokeOpacity: 0.85,
strokeWeight: 6
});
// seems to not be necesary
//map.refresh();
});
});
});
});
(in this new code, I just create the map in the onCreated, when the gmaps is loaded, and then, I make all the drawing in the onRendered. Btw, I used Template.xxx.map to transmit data between onCreated and onRendered, is that what i'm supposed to do?)
Try using nested templates for this. So that your wrapper template subscribes to data and only renders nested template when subscriptions is ready:
//wrapper template that manages subscription
Template.wrapper.onCreated(function() {
this.subscribe('allRuns');
});
Template.runs_show.onRendered(function() {
google_maps.KEY = "MY API KEY";
google_maps.load(function(google){
var map = new gmaps({
el: '#map-gmaps',
lat: -12.043333,
lng: -77.028333
});
Tracker.autorun(function() {
// Run.find will re-trigger this whole autorun block
// if any of the elements of the collection gets changed or
// element gets created or deleted from collection
// thus making this block reactive to data changes
// this will also work with findOne in case you only want to
// one run only
var runs = Run.find({"maxSpeed" : "75"}).fetch();
// map.clear() or something like that to remove all polylines
// before re-rendering them
runs.forEach(function(run){
map.drawPolyline({
path : path,
strokeColor : '#FC291C',
strokeOpacity : 0.85,
strokeWeight : 6
});
});
});
// ^^ this is pretty dumb and re-renders all items every time
// something more intelligent will only re-render actually
// changed items and don't touch those who didn't change but
// that will require a slightly more complex logic
});
});
wrapper.html:
<template name="wrapper">
{{#if Template.subscriptionsReady }}
{{> runs_show }}
{{/if}}
</template>
P.S. this is mostly pseudo code since I never tested it, so just use it as a guide
Seems the issue is that the subscribe callback is not a reactive context. Try doing what worked for others here and here, as well as putting the tracking in your onRendered.
Template.templateName.onRendered(function() {
var self = this;
self.autorun(function() {
self.subscribe('allRuns',function() {
Tracker.autorun(function(){
...
}
})
})
})

Return value from nested function in another function if uses .then() or other method (JavaScript, Maps APIs)

I wrote AngularJS application which shows Google, Yandex and Gis maps for specific coordinates, obtained from JSON object. JSON may contains [0...n] objects.
And it is well works with Google Maps API, but not with Yandex/Gis Maps API.
Yandex Maps:
// DOESN'T WORK
$scope.yandexMaps = function (city) {
ymaps.ready(init);
function init() {
$scope.mapContainer = document.createElement('div');
$scope.mapContainer.className = 'mapCon';
$scope.yandexMap = new ymaps.Map($scope.mapContainer, {
center: [city.lat, city.lng],
zoom: 12
});
$scope.placemark = new ymaps.Placemark([city.lat, city.lng]);
$scope.yandexMap.geoObjects.add($scope.placemark);
return $scope.mapContainer; //I NEED TO GET IT !
}
//BUT I NEED TO GET IT THERE !
};
Gis Maps:
// DOESN'T WORK
$scope.gisMaps = function (city) {
DG.then(init);
function init() {
$scope.mapContainer = document.createElement('div');
$scope.mapContainer.className = 'mapCon';
$scope.gisMap = DG.map($scope.mapContainer, {
center: [city.lat, city.lng],
zoom: 13
});
DG.marker([city.lat, city.lng]).addTo($scope.gisMap);
return $scope.mapContainer; //I NEED TO GET IT !
}
//BUT I NEED TO GET IT THERE !
};
The problem is that ymaps.ready(init); and DG.then(init); call init() functions only after they will be checked for ready map state. And I can't return $scope.mapContainer in both cases because they are in nested functions.
I tried to create global variable above init() functions and assign to this $scope.mapContainer, but when I return this global value in parent below init() function it is not visible. It is visible only in nested function.
YOU CAN SEE working JSFiddle here: https://jsfiddle.net/oxpgkLhj/2/
Please, open console to see errors
If you are commenting this part at the end of code:
//adding yandex map to common container
$scope.yandexMap = $scope.yandexMap(value);
$scope.yandexMap.id = "yandexMapContainer" + i;
angular.element($scope.container).append($scope.yandexMap);
and this:
//adding gis map to common container
$scope.gisMap = $scope.gisMaps(value);
$scope.gisMap.id = "gisMapContainer" + i;
angular.element($scope.container).append($scope.gisMap);
you will see perfectly worked Google Maps. I want to see Yandex and Gis Maps exactly the same. Please help...

Google map marker update with AJAX

I had this working when data was coming from static factory. Now data comes in from an AJAX call ($http) from a remote server and for some reason markers dont get put on the map.
Working plunker
Basically if I uncomment $http and replace the static data, it will not show up. It will show variable markers filled with right data, just wont populate the map
Kind of similar issue
i mean setting mode.state to true after the markers are loaded:
$scope.mode.state = false;
$scope.change_type = function(val) {
var markers = [];
$scope.eventMarkers = markers // clear the map of markers, before loading new
Events.venues(val.type).then(function(resp){
var venues = $.map(resp.data, function(value, index){return [value]})
for (var i = 0; i < venues.length; i++) {
event = venues[i]
markers.push(createMarker(i,event))
}
console.log(markers)
$scope.eventMarkers = markers
$scope.mode.state = true;
}, function(errror){
console.debug(error)
});
}

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