/* Public toilets all over Australia. Data taken from this data set: https://data.gov.au/dataset/national-public-toilet-map */ var DataManager = function () { var rawData = []; //function to fake what should happen server side. When returning a large amount of data perform the clustering server //side to save sending large amounts of data to the client. As the data is just in a js file for this example faking the server side //clustering using this function. Implement own clustering logic as appropriate, this doesn't do it particularly well. function fakeServerSideClustering(clusterRatio, maxSingleFlareCount, areaDisplayMode, map) { var itcount = 0; console.time("fake-server-side-cluster"); var webExtent = map.extent; //set up a grid system to do the clustering //get the total amount of grid spaces based on the height and width of the map (divide it by clusterRatio) - then get the degrees for x and y var xCount = Math.round(map.width / clusterRatio); var yCount = Math.round(map.height / clusterRatio); var xw = (webExtent.xmax - webExtent.xmin) / xCount; var yh = (webExtent.ymax - webExtent.ymin) / yCount; var gsxmin, gsxmax, gsymin, gsymax; var dataLength = rawData.length; //create an array of clusters that is a grid over the visible extent. Each cluster contains the extent (in web merc) that bounds the grid space for it. var clusters = []; for (var i = 0; i < xCount; i++) { gsxmin = webExtent.xmin + (xw * i); gsxmax = gsxmin + xw; for (var j = 0; j < yCount; j++) { gsymin = webExtent.ymin + (yh * j); gsymax = gsymin + yh; var ext = new esri.geometry.Extent({ xmin: gsxmin, xmax: gsxmax, ymin: gsymin, ymax: gsymax }); ext.setSpatialReference(new esri.SpatialReference({ "wkid": 102100 })); clusters.push({ extent: ext, clusterCount: 0, subTypeCounts: [], singles: [], points: [] }); } } var web, obj; for (var i = 0; i < dataLength; i++) { obj = rawData[i]; //get a web merc lng/lat for extent checking. Use web merc as it's flat to cater for longitude pole web = esri.geometry.lngLatToXY(obj.x, obj.y); //filter by visible extent first if (web[0] < webExtent.xmin || web[0] > webExtent.xmax || web[1] < webExtent.ymin || web[1] > webExtent.ymax) { continue; } var foundCluster = false; //loop cluster grid to see if it should be added to one for (var j = 0, jLen = clusters.length; j < jLen; j++) { var cl = clusters[j]; if (web[0] < cl.extent.xmin || web[0] > cl.extent.xmax || web[1] < cl.extent.ymin || web[1] > cl.extent.ymax) { continue; //not here so carry on } //recalc the x and y of the cluster by averaging the points again cl.x = cl.clusterCount > 0 ? (obj.x + (cl.x * cl.clusterCount)) / (cl.clusterCount + 1) : obj.x; cl.y = cl.clusterCount > 0 ? (obj.y + (cl.y * cl.clusterCount)) / (cl.clusterCount + 1) : obj.y; //push every point into the cluster so we have it for area checking if required. This could be omitted if never checking areas, or on demand at least if (areaDisplayMode) { cl.points.push([obj.x, obj.y]); } cl.clusterCount++; var subTypeExists = false; for (var s = 0, sLen = cl.subTypeCounts.length; s < sLen; s++) { if (cl.subTypeCounts[s].name === obj.facilityType) { cl.subTypeCounts[s].count++; subTypeExists = true; break; } } if (!subTypeExists) { cl.subTypeCounts.push({ name: obj.facilityType, count: 1 }); } cl.singles.push(obj); } } var results = []; //for every cluster that only has one point, just add the actual object to the result for (var i = 0, len = clusters.length; i < len; i++) { if (clusters[i].clusterCount === 1) { results.push(clusters[i].singles[0]); } else if (clusters[i].clusterCount > 0) { if (clusters[i].singles.length > maxSingleFlareCount) { clusters[i].singles = []; } results.push(clusters[i]); } } console.timeEnd("fake-server-side-cluster"); return results; } function getData() { return rawData; } function setData(data) { rawData = data; } return { getData: getData, setData: setData, fakeServerSideClustering: fakeServerSideClustering } }();