Can't access Leaflet map with Backbone.js - backbone.js

When initialising a Leaflet map with Backbone.js I can't access this exact map anymore.
E.g.:
mapView.map.locate({setView: true, maxZoom: 10});
will result in
TypeError: 'undefined' is not a function (evaluating 'mapView.map.locate({setView: true, maxZoom: 10})')
The map is initialized via a separate view in a dashboard view like:
this.mapView = new MapView();
$(this.$el).find('.content').append(this.mapView.el).find('.map').addClass('full').css({
'height': $(window).height() / 2
});
This view looks like:
var MapView = Backbone.View.extend({
template: _.template(""),
render: function ()
{
this.$el.html(this.template());
this.map = L.map(this.el).setView([48.00786, 13.17989], 8);
this.map = L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attribution: 'OpenStreetMap © Mitwirkende der OpenStreetMap'
}).addTo(this.map);
return this;
}
});
I can access the map object by just console.log'ing it. The result looks like:
_animated: true
_bgBuffer: HTMLDivElement
_clearBgBufferTimer: 4
_container: HTMLDivElement
_initHooksCalled: true
_leaflet_events: Object
_leaflet_id: 20
_limitedUpdate: function s() {var a=arguments;return n?(o=!0,void 0):(n=!0,setTimeout(function(){n=!1,o&&(s.apply(i,a),o=!1)},e),t.apply(i,a),void 0);}
_map: Object
_tileContainer: HTMLDivElement
_tileImg: HTMLImageElement
_tiles: Object
_tilesToLoad: 0
_url: "http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
options: Object
proto: Object
But why am I not able to access this map afterwards?
Thanks!

Problem solved. I just moved the whole map thing to the view and did not separate the map into another view. That's probably not the finest way to do this but it does it's job quite well.

Related

Angular-ui ui-map click event not receiving $params

I'm trying to implement Google maps in Angularjs using ui.Map (http://angular-ui.github.io/ui-map/)
I've followed the example pretty closely and the map loads, I can create a marker in the map center and the 'map-tilesloaded' event works fine.
My problem is adding a marker where the user clicks. The click function is receiving an empty $params parameter. In my controller:
$scope.newMapOptions = {
center : new google.maps.LatLng($scope.position.lat, $scope.position.lng),
zoom : 18,
mapTypeId : google.maps.MapTypeId.ROADMAP
};
$scope.getLocation = function() {
if (navigator.geolocation) {
return navigator.geolocation.getCurrentPosition(setPosition);
}
};
$scope.addMarker = function($event, $params) {
$scope.newTingMarker = new google.maps.Marker({
map : $scope.myNewTingMap,
position : $params[0].latLng
});
};
$scope.initMap = function() {
if (!$scope.mapLoaded)
$scope.getLocation();
$scope.mapLoaded = true;
};
function setPosition(pos) {
$scope.position = {
lat : pos.coords.latitude,
lng : pos.coords.longitude
};
$scope.meMarker = new google.maps.Marker({
map : $scope.myNewTingMap,
position : new google.maps.LatLng($scope.position.lat, $scope.position.lng)
});
$scope.myNewTingMap.setCenter(new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude));
$scope.$apply();
}
The html:
<div ui-map-info-window="myInfoWindow">
<b>Current location</b>
</div>
<div ui-map-marker="meMarker" ></div>
<div ui-map-marker="newTingMarker" ui-event="{'map-click': 'openMarkerInfo(newTingMarker)'}"></div>
<section id="newTingMap" >
<div ui-map="myNewTingMap" ui-options="newMapOptions" class="map-canvas"
ui-event="{'map-tilesloaded': 'initMap()', 'map-click': 'addMarker($event, $params)' }"></div>
</section>
$scope.addMarker should receive $event and $params where $params[0] has the latlng object. At the moment is it an empty array: []
I'm using angular 1.1.5, but I've tried using the same as the ui.Map example with no effect.
I should also note that this is in a view but putting it outside the view in the main controller makes no difference.
If I try to follow the code running from the ui-map directive I can see that the latlng object does start off in the event:
ui-map.js:
angular.forEach(eventsStr.split(' '), function (eventName) {
//Prefix all googlemap events with 'map-', so eg 'click'
//for the googlemap doesn't interfere with a normal 'click' event
google.maps.event.addListener(googleObject, eventName, function (event) {
element.triggerHandler('map-' + eventName, event);
//We create an $apply if it isn't happening. we need better support for this
//We don't want to use timeout because tons of these events fire at once,
//and we only need one $apply
if (!scope.$$phase){ scope.$apply();}
});
});
element.triggerHandler('map-' + eventName, event); ... has the latlng object in 'event' but is seems to get lost after that
Not sure what your issue is, I took your code and created a fiddle that works fine(something you should have done).
I did a console log when you click that logs the $params.
The most important thing to note is your code crashes at first because you reference $scope.position.lat before setting it. I updated it to default to RVA.
,
You do need to handle the case a little more gracefully.
function MapCtrl($scope, watchArray) {
var center;
if ($scope.position) {
center = new google.maps.LatLng($scope.position.lat, $scope.position.lng);
}
else {
center = new google.maps.LatLng(37.5410, 77.4329); //if null use rva
}
$scope.newMapOptions = {
center: center,
zoom: 18,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
...
}
Console.log:
[Ps]
v 0: Ps
> la: Q
> latLng: O
> pixel: Q
> __proto__: Ps
length: 1
> __proto__: Array[0]

How to initialise nested Backbone.js models

In my Application, I have the following JSON data format:
{
Item: {
property1: '',
...
}
}
Following the solution of this stackoverflow.com answer, I modeled my Backbond.js models the following way:
App.Models.Item = Backbone.Model.extend({
});
App.Models.ItemData = Backbone.Model.extend({
defaults: {
'Item': new App.Models.Item
}
});
I now want to bootstap the data to my App from the Backend system on the page load the following way:
var item = App.Models.ItemData({
{Item:
{property1: 'data'}
}
});
The problem I have now is that item.get('Item') returns a plain JavaScrip object and not a Backbone.Model object, because the defaults are overwritten. How can I create the Backbone.js object while ensuring that item.get('Item') is an App.Models.Item object?
I also have read that if you nest Backbone.Models, you should wirite custom getter methods, so the rest of your app dose not have to know about the internal data structure. If so, what is the right way to implement those setters and getters?
You can override the parse method on your ItemData model. No defaults required. The parse method will initialize an empty model, if one is not passed:
App.Models.ItemData = Backbone.Model.extend({
parse: function(attrs) {
attrs = attrs || {};
if(!(attrs.Item instanceof App.Models.Item))
attrs.Item = new App.Models.Item(attrs.Item);
return attrs;
}
});
And then initialize your ItemData model with the option parse:true:
var item = new App.Models.ItemData({Item:{property1: 'data'}}, {parse:true});

Leaflet markers from Backbone.js collection?

I am trying to build an application based on backbone.js and leaflet.
Users could drag the map and see markers on the map.
Markers can be selected by clicking on them. When selected they have to change their icon and the marker detailed information shown on a (not popup).
my backbone model consists of several entities:
Marker model contains
latitude, longitude
type,
title,
isSelected
Map model contains:
center of the map,
markers collection,
selected marker
anyone has any idea how i could make this kind of functionality?
how can i make leaflet markers as backbone views?
Backbone views and the leaflet object model are not a perfect fit, because the markers aren't contained within a DOM element, which is what Backbone.View.el is supposed to represent. Markers do of course have an element (accessible via marker._icon), but it doesn't exist until the marker is rendered to the map.
That said, you can represent the markers with Backbone views, you just can't use the events or any el related functionality. I've implemented similar views successfully using OpenLayers, which has the same "problem", and it works fine.
I think this is easiest to explain with code:
//MarkerView has no element
App.Views.MarkerView = Backbone.View.extend({
initialize: function(options) {
//pass map instance to the marker
this.map = options.map;
//create the marker object
this.marker = L.marker([this.model.get('longitude'), this.model.get('latitude')]);
},
render: function() {
//append marker to the map
this.marker.addTo(this.map);
//can't use events hash, because the events are bound
//to the marker, not the element. It would be possible
//to set the view's element to this.marker._icon after
//adding it to the map, but it's a bit hacky.
this.marker.on('click', this.onClick);
},
onClick: function() {
alert("click");
}
});
//MapView renders a map to the #map element
App.Views.MapView = Backbone.View.extend({
id:"#map",
render: function() {
//render map element
var map = this.map = L.map(this.$el.attr('id'))
.setView([this.model.get('centerLon'), this.model.get('centerLat') ], 13)
.addLayer(L.tileLayer(this.model.get('layerUrl'), { maxZoom: 18 }));
//render each marker
this.markerViews = this.model.get('markers').map(function(marker) {
return new App.Views.MarkerView({model:marker, map:map}).render();
});
}
});
Here's a demo on JSFiddle.

Backbone Boilerplate Layout Manager

Can someone help explain / provide an example on how to use the LayoutManager within the Backbone Bolierplate?
Within app.js I can see a useLayout function that extends the main app object. Within here it appears to be setting a base layout element:
// Helper for using layouts.
useLayout: function(name, options) {
// Enable variable arity by allowing the first argument to be the options
// object and omitting the name argument.
if (_.isObject(name)) {
options = name;
}
// Ensure options is an object.
options = options || {};
// If a name property was specified use that as the template.
if (_.isString(name)) {
options.template = name;
}
// Create a new Layout with options.
var layout = new Backbone.Layout(_.extend({
el: "#main"
}, options));
// Cache the refererence.
return this.layout = layout;
}
Is that correct? If so, do I somehow the use the 'UseLayout' function with the applications Router? ...to add different UI elements/nested views to the main view?
Thanks.
I will usually have an "app" object that stores all my settings needed throughout the application. This object then extends some useful functions like the one you listed above. For example:
var app = {
// The root path to run the application.
root: "/",
anotherGlobalValue: "something",
apiUrl: "http://some.url"
};
// Mix Backbone.Events, modules, and layout management into the app object.
return _.extend(app, {
// Create a custom object with a nested Views object.
module: function(additionalProps) {
return _.extend({ Views: {} }, additionalProps);
},
// Helper for using layouts.
useLayout: function(options) {
// Create a new Layout with options.
var layout = new Backbone.Layout(_.extend({
el: "#main"
}, options));
return this.layout = layout;
},
// Helper for using form layouts.
anotherUsefulFunction: function(options) {
// Something useful
}
}, Backbone.Events);
});
Now in my router I would do something like:
app.useLayout({ template: "layout/home" })
.setViews({
".promotional-items": new Promotions.Views.PromotionNavigation(),
".featured-container": new Media.Views.FeaturedSlider({
vehicles: app.vehicles,
collection: featuredCollection
})
}).render().then(function() {
//Do something once the layout has rendered.
});
I have just taken a sample from one of my applications, but I am sure you can get the idea. My main layout is basically just a layout template file which holds the elements so the views can be injected into their respective holders.
You would use it as if you're using a regular Backbone View. Instead of building the View directly, you can use this to create a new instance. The code you posted is a wrapper object on top of the Backbone Layout Manager extension with el: #main set as the default View element which is overridable.
var layout = new useLayout({ template: "#viewElement", ... });

Backbone.js view content keep multiplying instead of clearing

I'am new to Backbone.js and this problem has really got me stumped.
A view is built up from a collection, the collection results are filtered to place each set of results into their own array and then I make another array of the first items from each array, these are the 4 items displayed.
This works fine the first time the page is rendered but when I navigate away from this page and then go back the page now has 8 items, this pattern of adding 4 continues everytime I revisit the page.
// Locatore List Wrapper
var LocatorPageView = Backbone.View.extend({
postshop: [],
postbox: [],
postboxlobby: [],
postboxother: [],
closestPlaces: [],
el: '<ul id="locator-list">',
initialize:function () {
this.model.bind("reset", this.render, this);
},
render:function (eventName) {
//console.log(this)
// Loop over collecion, assigining each type into its own array
this.model.models.map(function(item){
var posttype = item.get('type').toLowerCase();
switch(posttype) {
case 'postshop':
this.postshop.push(item);
break;
case 'postbox':
this.postbox.push(item);
break;
case 'postbox lobby':
this.postboxlobby.push(item);
break;
default:
this.postother.push(item);
}
return ;
}, this);
// Create a closest Places array of objects from the first item of each type which will be the closest item
if (this.postshop && this.postshop.length > 0) {
this.closestPlaces.push(this.postshop[0]);
}
if (this.postbox && this.postbox.length > 0) {
this.closestPlaces.push(this.postbox[0]);
}
if (this.postboxlobby && this.postboxlobby.length > 0) {
this.closestPlaces.push(this.postboxlobby[0]);
}
if (this.postother && this.postother.length > 0) {
this.closestPlaces.push(this.postother[0]);
}
// Loop over the Closest Places array and append items to the <ul> contianer
_.each(this.closestPlaces, function (wine) {
$(this.el).append(new LocatorItemView({
model:wine
}).render().el);
}, this);
return this;
}
})
// Locator single item
var LocatorItemView = Backbone.View.extend({
tagName:"li",
template:_.template($('#singleLocatorTemplate').html()),
render:function (eventName) {
$(this.el).html(this.template(this.model.toJSON()));
return this;
},
events: {
"click .locator-map": "loadMap"
},
loadMap: function(e) {
e.preventDefault();
// Instantiate new map
var setMap = new MapPageView({
model: this.model,
collection: this.collection
});
var maptype = setMap.model.toJSON().type;
App.navigate('mappage', {trigger:true, replace: true});
setMap.render();
App.previousPage = 'locator';
}
});
window.App = Backbone.Router.extend({
$body: $('body'),
$wrapper: $('#wrapper'),
$header: $('#header'),
$page: $('#pages'),
routes: {
'' : '',
'locator': 'locator'
},
locator:function () {
this.$page.empty(); // Empty Page
this.places = new LocatorPageCollection(); // New Collection
this.placeListView = new LocatorPageView({model:this.places}); // Add data models to the collection
this.places.fetch();
this.$page.html(this.placeListView.render().el); // Append the renderd content to the page
header.set({title: 'Locator'}); // Set the page title
this.$body.attr('data-page', 'locator'); // Change the body class name
this.previousPage = ''; // Set previous page for back button
}
});
All the properties in your Backbone.View.extend argument are attached to the view's prototype. In particular, these properties:
postshop: [],
postbox: [],
postboxlobby: [],
postboxother: [],
closestPlaces: [],
end up attached to LocatorPageView.prototype so each LocatorPageView instance shares the same set of arrays and each time you use a LocatorPageView, you push more things onto the same set of shared arrays.
If you need any mutable properties (i.e. arrays or objects) in your Backbone views, you'll have to set them in your constructor:
initialize: function() {
this.postshop = [ ];
this.postbox = [ ];
this.postboxlobby = [ ];
this.postboxother = [ ];
this.closestPlaces = [ ];
}
Now each instance will have its own set of arrays.
This sounds like a classic Zombie View problem. Basically when you do this:
this.model.bind("reset", this.render, this);
in your view, you never unbind it. Thus, the view object is still bound to the model and can't be removed from memory. When you create a new view and reset, you have that listener still active which is why you see the duplicate view production. Each time you close and redo the view, you're accumulating listeners which is why it increases in multiples of 4.
What you want to do is unbind your listeners when you close out the view and rid your program of binds.
this.model.unbind("reset", this.render, this);
This should eliminate the pesky zombies. I'll add a link with more detailed information when I find it.
UPDATE - added useful references
I also ran into this problem a while back. It's quite the common gotcha with Backbone. #Derick Bailey has a really good solution that works great and explains it well. I've included the links below. Check out some of the answers he's provided in his history regarding this as well. They're all good reads.
Zombies! Run!
Backbone, JS, and Garbage Collection

Resources