https://github.com/ashkyd/leaflet.selectivejson

Plugin to selectively display points from a GeoJSON file on a Leaflet map.
https://github.com/ashkyd/leaflet.selectivejson

Last synced: about 1 month ago
JSON representation

Plugin to selectively display points from a GeoJSON file on a Leaflet map.

• Host: GitHub
• URL: https://github.com/ashkyd/leaflet.selectivejson
• Owner: AshKyd
• License: bsd-2-clause
• Created: 2014-04-18T07:39:49.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2014-07-29T21:02:56.000Z (over 10 years ago)
• Last Synced: 2024-11-09T21:34:07.672Z (about 1 month ago)
• Language: JavaScript
• Size: 172 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
Leaflet.selectivejson

=====================

Plugin to selectively display points from a GeoJSON file on a Leaflet map.

This is useful for displaying large datasets which can be zoomed for more detail.

Source Data

===========

This plugin will show items in order they are specified in the source data. For 

this reason you should sort your features by importance descending, otherwise the

results will seem random.

If you want to display multiple datasets you should merge them into the one

GeoJSON file prior to creating a new SelectiveJSON object, otherwise the layers

will act independently.

Options

=======

distance

--------

Minimum distance between points is calculated as the distance in metres

from the top left of the viewport to the bottom right of the vewport, divided by

this value.

Set to a lower value to increase the distance between points or a higher value

to show points tighter together.

displayCondition(latlng, properties)

----------------

A function to check whether this item should be displayed.

Is passed two parameters

* latlng - The L.LatLng object for this point.

* properties - The properties on this GeoJSON point.

Return true to display this item, false to continue through other checks.

pointToLayer

------------

A function to override rendering of points. Return a Leaflet layer of some kind.

See [GeoJSON.pointToLayer](http://leafletjs.com/reference.html#geojson-pointtolayer).

Sample

======

The following sample code shows all points with the isImportant property set to

true, as well as any other points that will fit within 10% of the size of the

viewport.

This example also uses the Leaflet.label plugin to bind a label to each point.

    // Selective cities.

    $.getJSON(cities,function(cities){

        L.selectiveJSON(cities,{

            distance: 10,

            displayCondition: function(latlng, properties){

                return properties.isImportant;

            },

            pointToLayer: function(latlng, properties){

                return L.circleMarker(latlng,{

                    radius: 2.5,

                    fillColor: 'black',

                    fillOpacity: 1,

                    stroke: false

                }).bindLabel(properties.name, { noHide: true });

            }

        }).addTo(map);

    });