CODEWITHSUNDEEP
javascriptopenlayers
Marcelo de Andrade
Marcelo de Andrade

Reputation: 332

How load a vectorSource without XHR

Using the latest version of Openlayers, 4.3.1, i set a vector source as follows:

this.vectorSource = new ol.source.Vector({
      url: `../assets/data/file.json`,
      format: new ol.format.TopoJSON()
    });

    this.vector = new ol.layer.Vector({
      source: this.vectorSource,
      style: this.style
    });

But the file, in some cases, needed a previous treatement through other function.

How i can load the file.json, treat him and use in ol.source.vector?

I trying with a response ajax too, where dataSource variable is a response from ajax call to same URL in the first example ../assets/data/file.json

vectorSource = new ol.source.Vector({
        features: (new ol.format.TopoJSON()).readFeatures(dataSource)
      });

Upvotes: 1

Views: 380

Answers (1)

ahocevar
ahocevar

Reputation: 5647

This can be done quite easily. Configure the ol.source.Vector without a URL. Instead, you can load your json yourself and turn it into an object with

var json = JSON.parse(dataSource);

Then modify the JSON object, and finally call

var features = new ol.format.TopoJSON().readFeatures(dataSource,
    {featureProjection: view.getProjection()});
vectorSource.addFeatures(features);

Note the featureProjection option, which is required unless your view has the same projection as your data source.

Upvotes: 1

Related Questions