idris-geojson

Utilities for querying and handling GeoJSON data

install

npm install idris-geojson

Usage

var ig = require('idris-geojson')

Select by properties

.selectProp( collection, object, callback )

ig.selectProp(countriesCollection, {continent: 'Europe'}, function(featureCollection) {
    // returns a featureCollection
})

.selectOneProp( collection, object, callback )

ig.selectOneProp(countriesCollection, {continent: 'Europe'}, function(feature) {
    // returns a feature
})

Select by bounding box

var bbox = [[min_longitude, min_latitude],[max_longitude, max_latitude]]

.selectWithinBbox( collection, bbox, callback )

Cuts the features to fit inside the bounding box

ig.selectWithinBbox(countriesCollection, [[-12,35],[26,63]], function(feature) {
    // returns a featureCollection
})

.selectOverlapBbox( collection, bbox, callback )

Keeps features that overlap with the bounding box

ig.selectOverlapBbox(countriesCollection, [[-12,35],[26,63]], function(feature) {
    // returns a featureCollection
})

Bounding box utilities

.bboxFromColl( collection, callback )

Get the bounding box of a collection

ig.bboxFromColl(collection, function(bbox) {
    // returns a bounding box
})

.bboxFromFeat( feature, callback )

Get the bounding box of a feature

ig.bboxFromFeat(collection, function(bbox) {
    // returns a bounding box
})

.featFromBbox( bbox, callback )

Returns a polygon feature

ig.featFromBbox(bbox, function(feature) {
    // returns a feature
})

Divide into geometry types

.divBy3Geotypes( collection , callback )

Divides the collection into three geometry types (points, linestrings and polygons). MultiPoint is in "Points", MultiLineString is in "LineStrings" and MultiPolygon is in "Polygons"

ig.divBy3Geotypes(collection, function(arrayOfCollections) {
    // returns a an array of featureCollection
})

The returned array contains objects with geoType and collection and could look like this

[ { geoType: 'Points',
    collection: { type: 'FeatureCollection', features: [Object] } },
  { geoType: 'LineStrings',
    collection: { type: 'FeatureCollection', features: [Object] } },
  { geoType: 'Polygons',
    collection: { type: 'FeatureCollection', features: [Object] } } ]

.divBy6Geotypes( collection , callback )

Divides the collection into all six geometry types (points, linestrings, polygons, multipoints, multilinestrings and multipolygons).

ig.divBy6Geotypes(collection, function(arrayOfCollections) {
    // returns a an array of featureCollection
})

The returned array contains objects with geoType and collection and could look like this

[ { geoType: 'Points',
    collection: { type: 'FeatureCollection', features: [Object] } },
  { geoType: 'MultiLineStrings',
    collection: { type: 'FeatureCollection', features: [Object] } },
  { geoType: 'LineStrings',
    collection: { type: 'FeatureCollection', features: [Object] } } ]

Validation

.separateValidFeatures( collection, callback )

Separate valid features from invalid features

ig.separateValidFeatures(collection, function(valid, invalid) {
    // returns two featureCollections
    //
    // features in the "invalid" collection have an error property with the error message
})

.onlyValidFeatures( collection, callback )

Get only the valid features of a collection.

ig.onlyValidFeatures(collection, function(featureCollection) {
    // returns a collection with only valid features
})