jcheng5

Using arbitrary Leaflet JS plugins with Leaflet for R

The Leaflet JS mapping library has lots of plugins available. The Leaflet package for R provides direct support for some, but far from all, of these plugins, by providing R functions for invoking the plugins.

If you as an R user find yourself wanting to use a Leaflet plugin that isn't directly supported in the R package, you can use the technique shown here to load the plugin yourself and invoke it using JS code.

mishari

[{"place_id":"97994878","licence":"Data \u00a9 OpenStreetMap contributors, ODbL 1.0. http:\/\/www.openstreetmap.org\/copyright","osm_type":"relation","osm_id":"161950","boundingbox":["30.1375217437744","35.0080299377441","-88.4731369018555","-84.8882446289062"],"lat":"33.2588817","lon":"-86.8295337","display_name":"Alabama, United States of America","place_rank":"8","category":"boundary","type":"administrative","importance":0.83507032450272,"icon":"http:\/\/nominatim.openstreetmap.org\/images\/mapicons\/poi_boundary_administrative.p.20.png"}]
[{"place_id":"97421560","licence":"Data \u00a9 OpenStreetMap contributors, ODbL 1.0. http:\/\/www.openstreetmap.org\/copyright","osm_type":"relation","osm_id":"162018","boundingbox":["31.3321762084961","37.0042610168457","-114.818359375","-109.045196533203"],"lat":"34.395342","lon":"-111.7632755","display_name":"Arizona, United States of America","place_rank":"8","category":"boundary","type":"administrative","importance":0.83922181098242,"icon":"http:\/\/nominatim.openst

rclark

There are a bunch of reasons why this is convoluted, mostly in building the URL to make the request:

1. You have to rely on an AJAX request, this example uses jQuery
2. To make a GetFeatureInfo request, you must provide a BBOX for a image, and the pixel coordinates for the part of the image that you want info from. A couple of squirrely lines of Leaflet code can give you that.
3. Output formats. The info_format parameter in the request. We don't know a priori which will be supported by a WMS that we might make a request to. See Geoserver's docs for what formats are available from Geoserver. That won't be the same from WMS to WMS, however.
4. WMS services return XML docs when there's a mistake in the request or in processing. This sends an HTTP 200, which jQuery doesn't think is an error.

patsweet

var intersections, // Geojson
    map,
    delaware, // Lat/Lng of center of Delaware
    streetMapUrl,
    streetMapLayer,
    geosearch,
    legend,
    polyindex,  // Custom ID for each point.
    highlightStyle = {
        fillColor: 'green',