Accepted Solutions
To make things a bit more dynamic (still on a hard coded geometry) I created an expression of a buffer of a point that grows in time and each point is given a symbology based on the distance from that growing circle:
var start_time = Date(2017, 11, 14, 10, 10, 0);
var curr_time = Now();
var dif_sec = DateDiff(curr_time, start_time, "seconds");
var buf_dist = Abs(dif_sec);
var json_pnt = '{"x":-8415299.294,"y":692928.204,"spatialReference":{"wkid":102100,"latestWkid":3857}}';
var source_pnt = Point(json_pnt);
var pnt = Geometry($feature);
var buf = Buffer(source_pnt, buf_dist, "meter");
var dist = Distance(pnt, buf, 'meters');
var result = "";
if (dist == 0) {
result = "Danger!";
} else if (dist <= 500) {
result = "Warning: 0 - 500m";
} else if (dist <= 1000) {
result = "Warning: 500m - 1km";
} else if (dist <= 1500) {
result = "Warning: 1km - 1.5km";
} else if (dist <= 2500) {
result = "Warning: 1.5km - 2.5km";
} else {
result = "No danger (>2.5km)";
}
return result;
Another one for the size of the symbol (inverted in this case to have larger symbols for those point closer to the circle):
var start_time = Date(2017, 11, 14, 10, 10, 0);
var curr_time = Now();
var dif_sec = DateDiff(curr_time, start_time, "seconds");
var buf_dist = Abs(dif_sec);
var json_pnt = '{"x":-8415299.294,"y":692928.204,"spatialReference":{"wkid":102100,"latestWkid":3857}}';
var source_pnt = Point(json_pnt);
var pnt = Geometry($feature);
var buf = Buffer(source_pnt, buf_dist, "meter");
var dist = Distance(pnt, buf, 'meters');
return dist;
Which results in something like this when you make use of the new Firefly symbols available in ArcGIS Online:
.
Simple example of what can be done could be visualizing the distance to a given point, using this simple script:
var json_pnt = '{"x":-8414809.305,"y":695061.198,"spatialReference":{"wkid":102100,"latestWkid":3857}}';
var given_pnt = Point(json_pnt);
var pnt = Geometry($feature);
var dist = Distance(pnt, given_pnt, 'meters');
return dist;With this result (if I use the distance for size and color):
This might be interesting if the points are dynamic and provided by for instance GeoEvent in real time, but the fact that I have to include a hard coded point in the expression does not seem right to me.
To make things a bit more dynamic (still on a hard coded geometry) I created an expression of a buffer of a point that grows in time and each point is given a symbology based on the distance from that growing circle:
var start_time = Date(2017, 11, 14, 10, 10, 0);
var curr_time = Now();
var dif_sec = DateDiff(curr_time, start_time, "seconds");
var buf_dist = Abs(dif_sec);
var json_pnt = '{"x":-8415299.294,"y":692928.204,"spatialReference":{"wkid":102100,"latestWkid":3857}}';
var source_pnt = Point(json_pnt);
var pnt = Geometry($feature);
var buf = Buffer(source_pnt, buf_dist, "meter");
var dist = Distance(pnt, buf, 'meters');
var result = "";
if (dist == 0) {
result = "Danger!";
} else if (dist <= 500) {
result = "Warning: 0 - 500m";
} else if (dist <= 1000) {
result = "Warning: 500m - 1km";
} else if (dist <= 1500) {
result = "Warning: 1km - 1.5km";
} else if (dist <= 2500) {
result = "Warning: 1.5km - 2.5km";
} else {
result = "No danger (>2.5km)";
}
return result;
Another one for the size of the symbol (inverted in this case to have larger symbols for those point closer to the circle):
var start_time = Date(2017, 11, 14, 10, 10, 0);
var curr_time = Now();
var dif_sec = DateDiff(curr_time, start_time, "seconds");
var buf_dist = Abs(dif_sec);
var json_pnt = '{"x":-8415299.294,"y":692928.204,"spatialReference":{"wkid":102100,"latestWkid":3857}}';
var source_pnt = Point(json_pnt);
var pnt = Geometry($feature);
var buf = Buffer(source_pnt, buf_dist, "meter");
var dist = Distance(pnt, buf, 'meters');
return dist;
Which results in something like this when you make use of the new Firefly symbols available in ArcGIS Online:
.
Since the update on December 5th it is possible to access other hosted feature services from the same datastore (service) or present in the same map. I have a blog in Spanish with an example provided by Esri here:
Mejoras en Arcade en ArcGIS Online con la Actualización de 5 de diciembre del 2018
To visualize the effect, you could have precincts and crimes:
... and maybe you are interested to know which crimes are within a precinct to show a summery in the pop-up of the precinct polygon like this:
This is done with the following Arcade Expression:
var used = {};
var distinctlist = [];
var counter = 0;
var crime = "";
var crimeList = "";
var intersectPrecinct = Intersects(FeatureSetByName($datastore,"Crimes"), $feature)
for(var f in intersectPrecinct) {
if (hasKey(used, f.ucrdesc)==false) {
used[f.ucrdesc]=1;
} else {
used[f.ucrdesc] += 1
}
}
for (var k in used) {
crime = k + ":" + used[k] +TextFormatting.NewLine
crimeList += crime
}
return crimeListYou will notice on line 6 there is a bit of magic going on: The "FeatureSetByName($datastore,"Crimes")", manages the access to the feature class crimes inside the same $datastore. On the same line an intersect is done to obtain only those crimes in the current precinct. After this a dictionary is created with an entry for each crime type and the related count. This information is structures at the end of the expression so that the pop-up will show this list of crime types and the corresponding count.
So in short, yes it is possible now to do this using Arcade v1.5
