CODEWITHSUNDEEP
openlayersuuidopenlayers-6
umbe1987
umbe1987

Reputation: 3588

How can I assign a unique identifier to OpenLayers layers?

Does OpenLayers library come with a way to assign/get a unique identifier for layers added to a map, or should I have to implement it myself?

This question arises from my need to uniquely identify various type of layers I add to my map (LayerGroup and TileLayer mostly), and to give the same reference id to each layer I create in parallel in a table-of-content-like DIV (like the ol-layerswitcher). This way I would be able to uniquely identfy my layer/group of layer in the map and its DOM context (where I can control e.g. its visibility, zoom, etc.).

I thought something similar would exist as it seems rather essential, but I cannot seem to find it in the docs not in the API.

This question is related to this other question of mine, where I essentially assume that an in-built method for assigning/retrieving ids for layers does not exist, and I am trying to figure out how to extend OpenLayers classes and methods to implement and get these properties whenever and wherever I need.

Upvotes: 6

Views: 3616

Answers (1)

umbe1987
umbe1987

Reputation: 3588

Thanks to @Mike for helping me finding a solution.

The answer was to use ol/util.getUid.

Calling getUid method and passing a layer to it, automatically assign a unique id to the layer which can be stored in a variable to use it somewhere else in an application.

Simple example:

import { getUid } from 'ol/util';
import TileLayer from 'ol/layer/Tile';

// create a new layer
var myLayer = new TileLayer();
var myLayerId = getUid(myLayer);
console.log(myLayerId) // logs the unique id of the layer

Upvotes: 10

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