Template:Map compare/doc

Embeds an interactive comparison between two maps based on {{Vector map}}. Drag the scrubber left and right to reveal more of one map or the other.

Usage

{{Map compare|lat=39.10599|lon=-84.5291|zoom=14|marker=no|layer=carto|layer2=baremaps}}

{{Map compare|lat=39.27541|lon=-84.28405|zoom=14|marker=no|layer=historic|date=1992-08-01|date2=2024-11-23}}

Parameters

This template supports all of the parameters of {{Vector map}}, with the addition of:

|layer2 =

The map layer to display on the right-hand side of the comparison. Defaults to the value of |layer =, which is always used on the left-hand side.

|date2 =

An ISO 8601-1 date by which to filter the data on the right-hand side of the comparison. Defaults to the value of |date =, which is always used on the left-hand side.

Additionally, |width = defaults to full (occupying the available space) instead of 400 pixels.

Implementation

This template simply inserts a placeholder <div> tag containing two transclusions of {{Vector map}}. MediaWiki:Gadget-maps.js, which is enabled by default for all users, detects this placeholder and responds by installing MapLibre GL Compare, which populates the placeholder with an interactive map copmarison. MapLibre GL Compare is loaded lazily from MediaWiki:Gadget-maplibre-gl-compare.js and MediaWiki:Gadget-maplibre-gl-compare.css, if and only if the page contains this placeholder, and only once even if there are multiple placeholders.

Template data

Embeds an interactive comparison between two vector maps. Drag the scrubber left and right to reveal more of one map or the other.

Template parameters

This template prefers block formatting of parameters.

Parameter		Description	Type	Status
Latitude	lat	Initial center latitude. Defaults to 0 degrees (equator). Default 0 Example 39.0799	Line	suggested
Longitude	lon	Initial center longitude. Defaults to 0 degrees (prime meridian). Default 0 Example -84.7037	Line	suggested
Zoom level	zoom	Initial vector zoom level. A vector zoom level is one less than a conventional raster zoom level seen in Leaflet-based websites such as openstreetmap.org or openhistoricalmap.org. May be a fractional number such as 10.5. Defaults to 11. Default 11 Example 10.5	Number	optional
Bearing	bearing	Initial bearing in degrees counterclockwise from north. Defaults to 0 degrees (due north). Default 0 Example 45	Number	optional
Pitch	pitch	Initial pitch in degrees away from the plane of the screen. Defaults to 0 degrees (lying flat on the screen). Default 0 Example 30	Number	optional
Width	width	Width of the map in pixels. “full” fits available space. Defaults to “full”. Suggested values full Default full Example 800	Line	optional
Height	height	Height of the map in pixels. Defaults to 400 pixels. Default 400 Example 300	Line	optional
Left layer	layer	The map layer to display on the left-hand side of the comparison. Defaults to “baremaps” (as in Apache Baremaps, which develops a vector port of OpenStreetMap Carto called OpenStreetMap Vecto). Suggested values americana baremaps carto cycle-map cyclosm historic humanitarian japanese scroll railway transport-map woodblock Default baremaps	Line	optional
Right layer	layer2	The map layer to display on the right-hand side of the comparison. Defaults to the value of “layer”, which is always used on the left-hand side. Suggested values americana baremaps carto cycle-map cyclosm historic humanitarian japanese scroll railway transport-map woodblock	Line	optional
Left date	date	An ISO 8601-1 date by which to filter the data on the left-hand side of the comparison. Any map feature must have existed by this date to appear. Only supported when “layer” is set to an OpenHistoricalMap-based stylesheet; ignored otherwise. Example 2004-08-09	Date	optional
Right date	date2	An ISO 8601-1 date by which to filter the data on the right-hand side of the comparison. Defaults to the value of “date”, which is always used on the left-hand side. Example 2004-08-09	Date	optional
Commons	commons	The page name of a GeoJSON map data file on Wikimedia Commons to load as an overlay. Include the .map file extension but exclude the Data: namespace. Example Kentucky Route 2354.map	Line	optional
Marker	marker	By default, a marker appears at the location specified by “lat” and “lon”. Set to “no” to hide this marker. Example no	Boolean	optional
Marker latitude	mlat	Latitude at which to place the marker. Defaults to the value of “lat”. Example 39.0799	Number	optional
Marker longitude	mlon	Longitude at which to place the marker. Defaults to the value of “lon”. Example -84.7037	Number	optional
Left attribution position	attribution-position	Corner of the left-hand side’s map in which the attribution control appears. Suggested values top-left top-right bottom-left bottom-right Default bottom-left Example top-left	Line	optional
Right attribution position	attribution-position2	Corner of the right-hand side’s map in which the attribution control appears. Suggested values top-left top-right bottom-left bottom-right Default bottom-right Example top-right	Line	optional

See also

• {{Vector map}}
• Module:CarouselMap – inserts a similar comparison based on a rotating configuration