geojson-validation

A GeoJSON Validation Library

GeoJSON-Validation

A GeoJSON Validation Library
Check JSON objects to see whether or not they are valid GeoJSON. Validation is based off of the GeoJSON Format Specification revision 1.0

npm install geojson-validation

var GJV = require("geojson-validation");
 
var validFeatureCollection = {
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
            "properties": {"prop0": "value0"}
        },
        {
            "type": "Feature",
            "geometry": {
                "type": "LineString",
                "coordinates": [
                    [102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [105.0, 1.0]
                ]
            },
            "properties": {
                "prop0": "value0",
                "prop1": 0.0
            }
        }
    ]
};
 
//simple test 
if(GJV.valid(validFeatureCollection)){
    console.log("this is valid GeoJSON!");
}
 
var invalidFeature =  {
    "type": "feature",
    "geometry": {
        "type": "LineString",
        "coordinates": [
            [102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [105.0, 1.0]
        ]
    },
    "properties": {
        "prop0": "value0",
        "prop1": 0.0
    }
};
 
//test to see if `invalidFeature` is valid 
GJV.isFeature(invalidFeature, function(validerrs){
    //log the errors 
    if(!valid){
       console.log(errs);
    }
});

first install gobally
npm install geojson-validation -g
Then you can use gjv to validate file such as
gjv file1 file2..
Or you can stream files to it cat file | gjv
gjv will either return a list of error or a valid if the files are indeed valid.

All Function return a boolean and take a JSON object that will be evalatued to see if it is a GeoJSON object, with the exception of define.

Arguments

  • geoJSON - a JSON object that is tested to see if it is a valid GeoJSON object
  • callback(boolean, errors) - boolean is whether or not the object is valid. errors is an array of validation errors for an invalid JSON object.

Alias: isGeoJSONObject
Checks if an object is a GeoJSON Object.


Checks if an object is a GeoJSON Object.


Checks if an object is a Geometry Object


Checks if an array is a Position


Checks if an object is a Point


Checks if an array can be interperted as coordinates for a MultiPoint


Checks if an object is a MultiPoint


Checks if an array can be interperted as coordinates for a LineString


Checks if an object is a Line String


Checks if an array can be interperted as coordinates for a MultiLineString


Checks if an object is a MultiLine String


Checks an array can be interperted as coordinates for a Polygon


Checks if an object is a Polygon


Checks if an array can be interperted as coordinates for a MultiPolygon


Checks if an object is a MultiPolygon


Checks if an object is a Geometry Collection


Checks if an object is a Feature Object


Checks if an object is a Feature Collection Object


Checks if an object is a Bounding Box


Define a Custom Validation for the give type. type can be "Feature", "FeatureCollection", "Point", "MultiPoint", "LineString", "MultiLineString", "Polygon", "MultiPolygon", "GeometryCollection", "Bbox", "Position", "GeoJSON" or "GeometryObject".

The function is passed the object being validated and should return a string or an array of strings representing errors. If there are no errors then the function should not return anything or an empty array. See the example for more.


Shout out to @VitoLau for the code for this example.

GJV = require("geojson-validation");
 
GJV.define("Position", function(position){
    //the postion must be valid point on the earth, x between -180 and 180 
    errors = [];
    if(position[0] < -180 || position[0] > 180){
        errors.push("the x must be between -180 and 180");
    }
    if(position[1] < -90 || position[1] > 90){
        errors.push("the y must be between -90 and 90");
    }
    return errors;
 
});
 
gj = {type: "Point", coordinates: [-200,3]};
//returns false 
GJV.isPoint(gj);

To run tests npm test
Test use mocha

  • Does not check ordering of Bouding Box coordinates
  • Does not check Coordinate Reference System Objects
  • Does not check order of rings for polygons with multiple rings