CODEWITHSUNDEEP
openlayers-3
P Viejo
P Viejo

Reputation: 41

Getting feature information from selection ol3

I am using Openlayers 3 and would like to create a graph real time from information contained on a selected object. I need to access the properties, but get('myfield') is not working. My features are in a GeoJSON vector layer.

var selectSingleClick = new ol.interaction.Select();
map.addInteraction(selectSingleClick);


map.on('singleclick', function(event){  
    mylayer.once('precompose',function(event){
      var selectedFeatures = selectSingleClick.getFeatures();
      readFeature(selectedFeatures);
    });
});

function readFeature(features){
    consoleText = document.getElementById('console');
//  When selected, getLength() returns 1, so selection is working.
//  consoleText.innerHTML = features.getLength();
    var myfeature = features[0];
    consoleText.innerHTML += myfeature.get('objectId');
}

Anybody can help me to understand what is going wrong? I have not much experience with Javascript.

Upvotes: 2

Views: 1170

Answers (2)

Sumanth Shastry
Sumanth Shastry

Reputation: 1159

If u look at the documentation of openlayers 3 http://openlayers.org/en/latest/apidoc/ol.interaction.Select.html#getFeatures selectSingleClick.getFeatures() returns ol.Collection() object which is an enhancement over normal Javascript array object. For more information on ol.Collection() have a look at this link. http://openlayers.org/en/latest/apidoc/ol.Collection.html

var myfeature = features[0];

is normal way to get an object from an array.

Upvotes: 1

P Viejo
P Viejo

Reputation: 41

I have found my problem. Trying to access the features by

var myfeature = features[0];

Correct syntax should be:

var myfeature = features.item(0);

But in previous examples features[0] have worked. Would be keen to understand why this is so...

Upvotes: 2

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