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How is leaflet used to show and hide layers?
The Leaflet package includes functions to show and hide map layers. You can allow users to decide what layers to show and hide, or programmatically control the visibility of layers using server-side code in Shiny. In both cases, the fundamental unit of showing/hiding is the group. A group is a label given to a set of layers.
How to assign layers to groups in R?
You assign layers to groups by using the group parameter when adding the layers to the map. leaflet () %>% addTiles () %>% addMarkers (data = coffee_shops, group = “Food & Drink”) %>% addMarkers (data = restaurants, group = “Food & Drink”) %>% addMarkers (data = restrooms, group = “Restrooms”) Many layers can belong to same group.
Is there a way to remove layers from a group?
Finally, you can remove the layers in a group using clearGroup. Note that this doesn’t just remove the layers from the group, it also removes them from the map. (It does not, however, remove the group itself from the map; it still exists, but is empty.)
How to show and hide layers on a map?
Only one layers control can be present on a map at a time. If you call addLayersControl multiple times, the last call will win. You can use the showGroup and hideGroup functions to show and hide groups from code.
The Leaflet package includes functions to show and hide map layers. You can allow users to decide what layers to show and hide, or programmatically control the visibility of layers using server-side code in Shiny. In both cases, the fundamental unit of showing/hiding is the group.
How does the opacity option in l.tilelayer.wms work?
The opacity option of L.TileLayer.WMS works as expected. See a working example. If you check the documentation for Leaflet 1.0, you’ll see that a L.TileLayer.WMS inherits options, methods and events from L.TileLayer and L.GridLayer. Opacity does something else.
How to hide unhide layers in leaflet-GeoJSON?
Making a feature visible again if a user clicks outside of it is a bit trickier since there’s no blur event on Leaflet’s layers. What you can do is listen for clicks on the map and reset all features then: Hiding individual markers it not currently supported, but should be coming in the future version 1.0 (see bug report ).
How to hide an icon on a leaflet?
You can hide a marker’s icon by providing an invisible icon with setIcon (), but you can not use setIcon () on eachLayer (). Instead, you can use Javascript .style properties (similar to CSS properties) on the icon to hide or show it. Thanks for contributing an answer to Geographic Information Systems Stack Exchange!
Which is the best leaflet for are shapes?
Very detailed (i.e. large) shape data can present a problem for Leafet, since it is all eventually passed into the browser and rendered as SVG, which is very expressive and convenient but has scalability limits. In these cases, consider using rmapshaper::ms_simplify, which does topology-preserving simplification conveniently from R.
What are the arguments for a rectangle leaflet?
It takes lng1, lng2, lat1, and lat2 vector arguments that define the corners of the rectangles. These arguments are always required; the rectangle geometry cannot be inferred from the data object.
How to add a popup to a leaflet?
Use the addPopups () function to add standalone popup to the map. A common use for popups is to have them appear when markers or shapes are clicked. Marker and shape functions in the Leaflet package take a popup argument, where you can pass in HTML to easily attach a simple popup.
How do you create a label in R-popup?
The labelOptions argument can be populated using the labelOptions () function. If noHide is false (the default) then the label is displayed only when you hover the mouse over the marker; if noHide is set to true then the label is always displayed. You can create labels without the accompanying markers using the addLabelOnlyMarkers function.
How to add labels on Leaflet map with no icon?
Before Leaflet 1.0: Use the Leaflet.label Plugin (already mentioned by geomajor56). With the Leaflet Label plugin, labels are directly tied to markers, but you can set the opacity of the marker to almost zero so only the label is visible.
How to make an image of a leaflet?
For this tutorial, we took the Leaflet logo and created four images out of it — 3 leaf images of different colors and one shadow image for the three: Note that the white area in the images is actually transparent.
How to create custom icons for leaflet classes?
The answer is simple: the real Leaflet classes are named with a capital letter (e.g. L.Icon ), and they also need to be created with new, but there are also shortcuts with lowercase names ( L.icon ), created for convenience like this: You can do the same with your classes too. OK, let’s finally put some markers with these icons on the map:
How to use WMS in a Leaflet map?
And the way to use that in a Leaflet map is simply: An instance of L.TileLayer.WMS needs at least one option: layers. Be careful, as the concept of “layer” in Leaflet is different from the concept of “layer” in WMS! WMS servers define a set of layers in the service.
How does layers control work in JavaScript leaflet?
The layers control is smart enough to detect what layers we’ve already added and have corresponding checkboxes and radioboxes set. Also note that when using multiple base layers, only one of them should be added to the map at instantiation, but all of them should be present in the base layers object when creating the layers control.
Which is an optional argument in layer control leaflet?
Both arguments are optional: you can pass just a base layers object by omitting the second argument, or just an overlays objects by passing null as the first argument. In each case, the omitted layer type will not appear for the user to select. Note that we added grayscale and cities layers to the map but didn’t add streets.
How to create a layergroup in leafletjs?
Follow the steps given below to create a LayerGroup and add it to the map. Step 1 − Create a Map object by passing a < div > element (String or object) and map options (optional). Step 2 − Create a Layer object by passing the URL of the desired tile.
How do you assign a layer to a group?
You assign layers to groups by using the group parameter when adding the layers to the map. Many layers can belong to same group. But each layer can only belong to zero or one groups (you can’t assign a layer to two groups). Groups and Layer IDs may appear similar, in that both are used to assign a name to a layer.
How are layer IDs and groups the same?
Groups and Layer IDs may appear similar, in that both are used to assign a name to a layer. However, they differ in that layer IDs are used to provide a unique identifier to individual markers and shapes, etc., while groups are used to give shared labels to many items.