Example code for blog showing D3's asynchronous loading of CSV files for visualization

d3_load_csv_asynchronously.js

<!-- D3js imports to load CSV data -->
<script src="https://d3js.org/d3-collection.v1.min.js"></script>
<script src="https://d3js.org/d3-dispatch.v1.min.js"></script>
<script src="https://d3js.org/d3-dsv.v1.min.js"></script>
<script src="https://d3js.org/d3-request.v1.min.js"></script>
<script src="https://d3js.org/d3-queue.v3.min.js"></script>

<!-- load multiple data asynchronously, defer visualization until complete -->
d3.queue()
.defer(d3.csv, "./data/spotmeka_points.csv")
.defer(d3.csv, "./data/spotmeka_planes.csv")
.await(function(error, points_file, planes_file,) {
    if (error) {
        console.error('D3: Error loading CSV: ' + error);
    }
    else {
        points_dataset = points_file;
        planes_dataset = planes_file;
        
        init();
        animate();
    }
});