Load JSON file and append it to a map

Question

I want to load in a json file and append it to a Leaflet-Map.

<input type='file' accept='Json' onchange='loadFile(event)'>

I'm struggling to work with the content of the JSON file, once it is uploaded. An example of a JSON file would be :

{
    "type": "FeatureCollection",
    "features": 
    [
        {
        "type": "Feature",
        "properties": {
            "name": "Lagoa Stadium",
            "coordinate":"-22.975801, -43.217316",
            "venue_type": "Outdoor area",
            "event": [{"name":"Canoe Sprint","date_start":"2016-08-15", "date_end":"2016-08-20"},
                    {"name":"Rowing","date_start":"2016-08-6", "date_end":"2016-08-13"}],
            "link": "https://www.rio2016.com/en/venues/lagoa-stadium",
            "images":["http://secure.rio2016.com/sites/default/files/imagecache/360x270_maps_cities/lagoa_aereas_secao01_alexferro_05032015-9156_1.jpg", "https://upload.wikimedia.org/wikipedia/commons/6/6a/1_lagoa_rodrigo_de_freitas_rio_de_janeiro_2010.jpg","http://www.rio-de-janeiro-travel-information.com/images/marina-da-gloria-rio-de-janeiro-2016-olympics.jpg"],
            "capacity": "14,000",
            "parking": "-22.983465, -43.198912"
        },
        "geometry": 
        {
            "type": "Polygon",
            "coordinates": [
            [
                [
                  -43.21497917175292,
                  -22.979493188378516
                ],
                [
                  -43.21643829345703,
                  -22.9790190701661
                ],
                [
                  -43.21772575378418,
                  -22.97870299043356
                ],
                [
                  -43.217811584472656,
                  -22.977596705547032
                ],
                [
                  -43.21695327758788,
                  -22.976411390260754
                ],
                [
                  -43.2161808013916,
                  -22.975068020367633
                ],
                [
                  -43.21592330932617,
                  -22.971828073334315
                ],
                [
                  -43.216352462768555,
                  -22.970089533152084
                ],
                [
                  -43.21738243103027,
                  -22.968667074553263
                ],
                [
                  -43.21703910827637,
                  -22.967323627688746
                ],
                [
                  -43.21566581726074,
                  -22.96558502957624
                ],
                [
                  -43.21446418762207,
                  -22.96432058054304
                ],
                [
                  -43.212318420410156,
                  -22.96337223600826
                ],
                [
                  -43.21051597595215,
                  -22.962977090489098
                ],
                [
                  -43.20914268493652,
                  -22.96313514883533
                ],
                [
                  -43.2063102722168,
                  -22.962819031958123
                ],
                [
                  -43.20510864257812,
                  -22.96305611968531
                ],
                [
                  -43.204078674316406,
                  -22.964083495032888
                ],
                [
                  -43.20356369018555,
                  -22.966138222309887
                ],
                [
                  -43.20356369018555,
                  -22.96740265434445
                ],
                [
                  -43.20845603942871,
                  -22.971828073334315
                ],
                [
                  -43.207340240478516,
                  -22.974830953706174
                ],
                [
                  -43.204593658447266,
                  -22.973803660034452
                ],
                [
                  -43.201160430908196,
                  -22.974830953706174
                ],
                [
                  -43.20047378540039,
                  -22.97609530442847
                ],
                [
                  -43.20004463195801,
                  -22.97751768485142
                ],
                [
                  -43.20124626159668,
                  -22.978623970384902
                ],
                [
                  -43.202362060546875,
                  -22.979256129480273
                ],
                [
                  -43.207426071166985,
                  -22.980441419812312
                ],
                [
                  -43.214378356933594,
                  -22.980125343407142
                ],
                [
                  -43.21497917175292,
                  -22.979493188378516
                ]
              ]
            ]
        }
    }
    ]
}

How do I read out the content of this file and load it into my Map?
I managed to load a JSON file that is on my server by using this:

$.getJSON('CompleteList.json', function (geojson) {
  jsonlayer = L.geoJson(geojson, {
    onEachFeature: function (feature, layer) {
      layer.bindPopup(feature.properties.name);
    }
  }).addTo(map);

Right now I loaded in the file and saved it in a variable... But what now?

var loadFile = function(event) {
    // Init
    var input = event.target;
    var reader = new FileReader();

    // Read the file
    reader.readAsText(input.files[0]);

    // Invoked when file is loading. 
    reader.onload = function(){

        // parse file to JSON object
        var jsonObject = reader.result;
        console.log(jsonObject);

    };
};

I hope I'm not missing anything and that it is not too much of a stupid question :D

It is too much code to post my whole project but right now it looks like this:

Answer 1

I guess once you included the Leaflet-Map library, JSON object will have function addTo(), so you need to parse the json object first.

var loadFile = function(event) {
// Init
var input = event.target;
var reader = new FileReader();

// Read the file
reader.readAsText(input.files[0]);

// Invoked when file is loading. 
reader.onload = function(){

    // parse file to JSON object
    var jsonObject = reader.result;
    var json = JSON.parse(jsonObject);
    jsonlayer = L.geoJson(json, {
onEachFeature: function (feature, layer) {
  layer.bindPopup(feature.properties.name);
}).addTo(map);
    console.log(jsonObject);

};
};

Answer 2

You successfully read the content of your user file as text.

Now you need to convert that text into a JS object (actually GeoJSON, but it is really just a plain JS object that follows a specific convention).

For that, you simply use JSON.parse().

Then you can feed it into Leaflet L.geoJson() factory.