GeoJSON/GeoCouch questions from a newb [duplicate]

Question

I am new to JSON and GeoJSON and would like to start to use this but I am a little confused about some things. Perhaps you can help me out:

1) Is there a GeoJSON validator out there? 2) Is the text below valid GeoJSON? To be a valid GeoJSON file do all the GeoJSON objects have to live in a GeoJSON array or can they be stored willie nellie as below?

The data below is a return from the geocouch example on github:

{
"rows": [
    {
        "id": "augsburg",
        "bbox": [
            10.898333,
            48.371667,
            10.898333,
            48.371667
        ],
        "geometry": {
            "type": "Point",
            "coordinates": [
                10.898333,
                48.371667
            ]
        },
        "value": [
            "augsburg",
            [
                10.898333,
                48.371667
            ]
        ]
    },
    {
        "id": "oakland",
        "bbox": [
            -122.270833,
            37.804444,
            -122.270833,
            37.804444
        ],
        "geometry": {
            "type": "Point",
            "coordinates": [
                -122.270833,
                37.804444
            ]
        },
        "value": [
            "oakland",
            [
                -122.270833,
                37.804444
            ]
        ]
    }
]

}

Answer 1

GeoJSON is also simply JSON, so I usually run it through the validator at http://jsonlint.com/ to check it passes this first. Unfortunately I don't think there is an online validator specific to GeoJSON.

You can however use the GDAL GeoJSON driver to try and load or get information about the dataset - if it fails it's invalid. You can also use the Python Shapely library to check features as it uses a GeoJSON-like notation for geometry.

Your example seems to be missing some type attributes - features must have a type attribute and can be grouped in collections if needed. The key criteria for GeoJSON objects (from the spec) are:

• GeoJSON always consists of a single object
• The GeoJSON object may have any number of members (name/value pairs).
• The GeoJSON object must have a member with the name "type"
• The value of the type member must be one of: "Point", "MultiPoint", "LineString", "MultiLineString", "Polygon", "MultiPolygon", "GeometryCollection", "Feature", or "FeatureCollection". The case of the type member values must be as shown here.
• A GeoJSON object may have an optional "crs" member, the value of which must be a coordinate reference system object
• A GeoJSON object may have a "bbox" member, the value of which must be a bounding box array

The GDAL driver also had issues if I did not set a "crs" value

For more details take a look at the full GeoJSON specification and examples.

I also found the GeoJSON from CloudMade's services very useful for comparison - http://developers.cloudmade.com/projects/geocoding/examples

Answer 2

I don't know of a validator but there is a spec (http://geojson.org/geojson-spec.html) you can consult.