0

I want to extract my MongoDB query in a GeoJSON format it order to be able to visualize the result. I use Robomongo, which seems to be able to generate a JSON format. After I run the query, this file gets produced:

{"result" : [ 
        {
            "_id" : ObjectId("5627ff79ce2790eea0d96ba3"),
            "type" : "FeatureCollection",
            "crs" : {
                "type" : "name",
                "properties" : {
                    "name" : "urn:ogc:def:crs:OGC:1.3:CRS84"
                }
            },
            "features" : {
                "type" : "Feature",
                "properties" : {
                    "id" : 1250.0000000000000000,
                    "osm_id" : 87222664.0000000000000000,
                    "name" : "29th Avenue Station",
                    "type" : "yes"
                },
                "geometry" : {
                    "type" : "MultiPolygon",
                    "coordinates" : [ 
                        [ 
                            [ 
                                [ 
                                    -123.0463325098070600, 
                                    49.2443216480303650
                                ], 
                                [ 
                                    -123.0462832242164000, 
                                    49.2443726938207080
                                ], 
                                [ 
                                    -123.0453115101814800, 
                                    49.2439719550299630
                                ], 
                                [ 
                                    -123.0453609634102200, 
                                    49.2439209930586800
                                ], 
                                [ 
                                    -123.0463325098070600, 
                                    49.2443216480303650
                                ]
                            ]
                        ]
                    ]
                }
            }
        }, 
        {
            "_id" : ObjectId("5627ff79ce2790eea0d96ba3"),
            "type" : "FeatureCollection",
            "crs" : {
                "type" : "name",
                "properties" : {
                    "name" : "urn:ogc:def:crs:OGC:1.3:CRS84"
                }
            },
            "features" : {
                "type" : "Feature",
                "properties" : {
                    "id" : 9033.0000000000000000,
                    "osm_id" : 197598621.0000000000000000,
                    "name" : "Electric Avenue",
                    "type" : "yes"
                },
                "geometry" : {
                    "type" : "MultiPolygon",
                    "coordinates" : [ 
                        [ 
                            [ 
                                [ 
                                    -123.1247329764166500, 
                                    49.2812495473848170
                                ], 
                                [ 
                                    -123.1243329081781800, 
                                    49.2815073747264310
                                ], 
                                [ 
                                    -123.1244402803578200, 
                                    49.2815791238176080
                                ], 
                                [ 
                                    -123.1247323058644000, 
                                    49.2817758470851000
                                ], 
                                [ 
                                    -123.1243665196099100, 
                                    49.2820086963552630
                                ], 
                                [ 
                                    -123.1243131268866800, 
                                    49.2820425592440760
                                ], 
                                [ 
                                    -123.1242579739638100, 
                                    49.2820068523365650
                                ], 
                                [ 
                                    -123.1237645313239900, 
                                    49.2816875856446760
                                ], 
                                [ 
                                    -123.1237276509500200, 
                                    49.2816641163157950
                                ], 
                                [ 
                                    -123.1236146628952400, 
                                    49.2815920319484920
                                ], 
                                [ 
                                    -123.1237309198922500, 
                                    49.2815131582396190
                                ], 
                                [ 
                                    -123.1237663753426800, 
                                    49.2814915329294370
                                ], 
                                [ 
                                    -123.1240143120385500, 
                                    49.2813217993901840
                                ], 
                                [ 
                                    -123.1240598257727800, 
                                    49.2812880203204030
                                ], 
                                [ 
                                    -123.1244141288199200, 
                                    49.2810538299457330
                                ], 
                                [ 
                                    -123.1246444635191300, 
                                    49.2811970766709630
                                ], 
                                [ 
                                    -123.1247329764166500, 
                                    49.2812495473848170
                                ]
                            ]
                        ]
                    ]
                }
            }
        }, 
        {
            "_id" : ObjectId("5628022bce2790eea0d96baa"),
            "type" : "FeatureCollection",
            "crs" : {
                "type" : "name",
                "properties" : {
                    "name" : "urn:ogc:def:crs:OGC:1.3:CRS84"
                }
            },
            "features" : {
                "type" : "Feature",
                "properties" : {
                    "id" : 721.0000000000000000,
                    "osm_id" : 60007793.0000000000000000,
                    "name" : "1st Avenue Marketplace",
                    "type" : "retail",
                    "area" : 0.0000020000000000,
                    "z_order" : 7.0000000000000000
                },
                "geometry" : {
                    "type" : "MultiPolygon",
                    "coordinates" : [ 
                        [ 
                            [ 
                                [ 
                                    -123.0468456499193300, 
                                    49.2685273271100070
                                ], 
                                [ 
                                    -123.0468340828929600, 
                                    49.2693428862887970
                                ], 
                                [ 
                                    -123.0443349346427300, 
                                    49.2693247813779180
                                ], 
                                [ 
                                    -123.0443671211509300, 
                                    49.2685336973564180
                                ], 
                                [ 
                                    -123.0468456499193300, 
                                    49.2685273271100070
                                ]
                            ]
                        ]
                    ]
                }
            }
        }
    ],
    "ok" : 1.0000000000000000
}

I am trying to test the validity of my file using GeoJSONLint but it prompts that the file is not serializeable.

Do you know how can I extract a GeoJSON from a query or somehow convert the JSON to GeoJSON? My file seems to follow the GeoJSON specifications but I was not able to find any tool to do the job.

2

there's a small issue with that JSON.

First, try jsonlint on the whole thing, you'll see that it complains about the format of the 3 "_id" properties. If you replace those with for example 123, 456, 789, it parses correctly.

Then if you use a graphical JSON viewer such as this one, you'll see that this JSON defines an object that contains a property named "result" being a list of 3 elements, and a status code property. The value of the "features" property of each of the 3 elements in the list is valid GeoJSON, which you can verify by pasting it into geojsonlint, for example this excerpt being the value from the first element:

        {
            "type" : "Feature",
            "properties" : {
                "id" : 1250.0000000000000000,
                "osm_id" : 87222664.0000000000000000,
                "name" : "29th Avenue Station",
                "type" : "yes"
            },
            "geometry" : {
                "type" : "MultiPolygon",
                "coordinates" : [ 
                    [ 
                        [ 
                            [ 
                                -123.0463325098070600, 
                                49.2443216480303650
                            ], 
                            [ 
                                -123.0462832242164000, 
                                49.2443726938207080
                            ], 
                            [ 
                                -123.0453115101814800, 
                                49.2439719550299630
                            ], 
                            [ 
                                -123.0453609634102200, 
                                49.2439209930586800
                            ], 
                            [ 
                                -123.0463325098070600, 
                                49.2443216480303650
                            ]
                        ]
                    ]
                ]
            }
        }
  • and on a bit more inspection, I see that the entire value of each of the 3 elements is almost valid geojson - first replace those objectid values like I described, then geojsonlint complains thusly: "A FeatureCollection's "features" property must be an array." If you enclose the value of the "features" property in braces to make it an array, it parses correctly. – MC5 Oct 22 '15 at 19:18
  • Thanks, I am stuck in: A FeatureCollection must have a "features" property. Aren't my "features" already enclosed by braces already? Can you show the format you are referring to? – Menelaos Kotsollaris Oct 22 '15 at 19:57
  • sorry, meant 'brackets' in that comment, not 'braces'. instead of "features" : {blah blah} it should be "features" : [{blah blah}] – MC5 Oct 22 '15 at 20:35
  • Thank you for your help. I will upload a complete answer this day; probably I will create a script to do some of the required parsing based on your annotations :) – Menelaos Kotsollaris Oct 22 '15 at 20:59
1

Thanks to MC5, I managed to convert my JSON to GeoJSON and visualized them via Google Drag and Drop GeoJSON. I used the following REGEX's:

  1. "features" : \{.*|"coordinates"[^}]*\K\}|"type" : "Feature"|"ok" : 1.0000000000000000|"id".*,|"_id" : ObjectId\(.*,
  2. "type" : "FeatureCollection",[^}]*\}, replace with "type" : "Feature",

Please notice that your file might follow a different structure, since the way you project the data obviously effects the output file. In such a case, extra modification is required.

You can view the the analytical description of the logic in this detailed answer.

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