@polar/plugin-layer-chooser
v1.2.1
Published
LayerChooser plugin for POLAR that adds a layer selection and configuration UI element for both backgrounds and overlays.
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LayerChooser
The tool offers layer selection to the user.
Scope
The LayerChooser offers an additive (usually Overlays, technically named with type: 'mask'
) and an exclusive (usually background maps, type: 'background'
) selection of layers to the users.
Order of layers within a layer is currently always as initially configured.
Configuration
The tool does not require any configuration for itself, but is based on the mapConfiguration.layers
.
It will infer id
and name
from that configuration.
This plugin requires the configuration of mapConfiguration.layer.type
.
Also, this plugin also supports the optional configuration parameters mapConfiguration.layer.hideInMenu
, mapConfiguration.layer.minZoom
, mapConfiguration.layer.maxZoom
, mapConfiguration.layer.options
and mapConfiguration.layer.visibility
which are described in more depth in the following table.
| fieldName | type | description |
| - | - | - |
| type | enum["background", "mask"] | Layer handling. Backgrounds are mutually exclusive, masks ("overlays") can be stacked. |
| hideInMenu | boolean? | Can be set for layers of type 'mask'
to hide them in the selection menu. |
| maxZoom | number? | If set, layer only available (and selectable) up to this zoom level. |
| minZoom | number? | If set, layer only available (and selectable) from this zoom level on. |
| options | options? | Shows a layer-specific sub-menu; its contents are configurable. |
| visibility | boolean? | Initial visibility. Defaults to false
. |
For details on the displayComponent
attribute, refer to the Global Plugin Parameters section of @polar/core
.
Example configuration:
layers: [
{
id: backgroundmap,
visibility: true,
type: 'background',
name: 'Basemap Grayscale',
},
{
id: memorialsWFS,
visibility: false,
hideInMenu: true,
type: 'mask',
name: 'Memorial (WFS)',
minZoom: 7,
},
]
layer.options
An option wheel will appear in the layer chooser that allows opening a sub-menu with configured configuration options for the end user.
| fieldName | type | description | | - | - | - | | layers | layer.options.layers | If configured, all configured layers of the layer can be turned off and on by the user. ⚠️ Only implemented for WMS. Only implemented for top layers; that is, only first level of nesting is considered. |
Example configuration:
options: {
layers: {
order: '6,24,25,4,3,2,1,0',
title: {
'6': 'Monument area',
'24': 'Majority of structures',
'25': 'Material group',
'4': 'Architectural monument',
'3': 'Natural monument',
'2': 'Water bodies',
'1': 'Architectural monument (area)',
'0': 'Natural monument (area)',
},
legend: true,
},
},
layer.options.layers
This field is named like this to match the OGC specification for their name; that is, layers have layers that may have layers that may have layers, and so on. However, only the first level (a layer's layers) is currently implemented.
| fieldName | type | description |
| - | - | - |
| legend | boolean | Record<name, legendUrl>? | Legend image to be used for sub-layer. If false, no image is displayed. If true, it is assumed an image exists in the layer's GetCapabilities, and that will be used. If Record, it maps the layer name to a linked image. The legendUrl
can be any valid reachable image URL. |
| order | string? | Optional. If not given, field layers
from service description will be used, and defines order of options. If layer defined in service description's layers
and order
, it's initially on. If only in order
, it's initially off. If only in layers
, it's always-on. If in neither, it's always-off. |
| title | boolean | Record<name, layerName>? | Title to be displayed for sub-layer. If false, layer name itself will be used as given in service description 'layers' field. If true, it is assumed a name exists in the layer's GetCapabilities, and that will be used. If Record, it maps the layer name to an arbitrary display name given by the configuration. The layerName
can be any string. |
Example configuration:
layers: {
order: '6,24,25,4,3,2,1,0',
title: {
'6': 'Monument area',
'24': 'Majority of structures',
'25': 'Material group',
'4': 'Architectural monument',
'3': 'Natural monument',
'2': 'Water bodies',
'1': 'Architectural monument (area)',
'0': 'Natural monument (area)',
},
legend: true,
},