Map Utilities

Overview

This module provides core map utility functions for time-series manipulation, feature identification, and GeoJSON data handling.

Functions

getNearestTime(time, times, sorted?)

Finds the nearest time in a list of Moment.js time values to a given reference time.

• Parameters:
  • time (Moment): The reference time.
  • times (Array<Moment>): Array of Moment.js time objects to search through.
  • sorted (boolean, default false): When true, assumes times is sorted in ascending order and uses a faster binary-style search.
• Returns: { index: number, difference: number } — The index of the nearest time and the absolute difference in milliseconds. index is -1 if times is empty.

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getTimeInterval(times, mode?)

Computes the minimum or maximum interval between consecutive times in a list.

• Parameters:
  • times (Array<Moment>): Array of Moment.js time objects.
  • mode ('minimum' | 'maximum', default 'minimum'): Whether to return the smallest or largest interval.
• Returns: number — The interval in milliseconds.

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getFeatureId(feature, layer)

Extracts the unique identifier of a GeoJSON feature based on the layer's featureId configuration. Supports compound (multi-field) identifiers.

• Parameters:
  • feature (Object): A GeoJSON feature.
  • layer (Object): The layer definition containing featureId (string or array of strings). Defaults to '_id' when not set.
• Returns: string — The feature identifier, built by joining field values with -.

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getFeatureLabel(feature, layer)

Extracts a human-readable label for a feature based on the layer's featureLabel configuration. Supports compound (multi-field) labels.

• Parameters:
  • feature (Object): A GeoJSON feature.
  • layer (Object): The layer definition containing featureLabel (string or array of strings). Defaults to 'name'.
• Returns: string — The label, built by joining field values with -.

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coordinatesToGeoJSON(lat, lon, format, options)

Creates a GeoJSON Point feature from coordinates, with a formatted coordinate string as the name property.

• Parameters:
  • lat (number): Latitude.
  • lon (number): Longitude.
  • format (string): A formatcoords format string.
  • options (Object): Additional options passed to formatcoords.
• Returns: Object — A GeoJSON Feature with Point geometry and a name property.

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getGeoJsonFeatures(geoJson)

Normalises various GeoJSON input formats into a flat array of features.

• Parameters:
  • geoJson (Object | Array): A GeoJSON Feature, FeatureCollection, or array of features.
• Returns: Array — An array of GeoJSON Feature objects.