Files
openlayers/examples/tracing.html
Olivier Guyot 6641832621 Improvements to the tracing example
* no embedded geojson
* better behaviour on draw end (no lingering preview line)
* clearer comments
* support for multi polygons to snap to
2020-02-11 11:03:38 +01:00

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930 B
HTML

---
layout: example.html
title: Tracing around a polygon
shortdesc: Example of setting up a draw interaction to easily snap to an existing feature.
docs: >
This example showcases how the draw interaction API can be set up to make snapping along
an existing geometry easier while preserving topology, which is sometimes called "tracing".
When the user clicks on two different points on the Idaho state border,
the part of the border comprised between these two points is added to
the currently drawn feature.
This leverages the `appendCoordinates` method of the `ol/interaction/Draw` interaction.
tags: "draw, trace, snap, vector, topology"
---
<div id="map" class="map"></div>
<form class="form-inline">
<label>Geometry type &nbsp;</label>
<select id="type">
<option value="Polygon">Polygon</option>
<option value="LineString">LineString</option>
<option value="None">None</option>
</select>
</form>