Implement circle filter for dataviews

lib/api/map/dataview-layergroup-controller.js

@@ -18,6 +18,7 @@ const ALLOWED_DATAVIEW_QUERY_PARAMS = [
     'own_filter', // 0, 1
     'no_filters', // 0, 1
     'bbox', // w,s,e,n
+    'circle', // json
     'start', // number
     'end', // number
     'column_type', // string

lib/backends/dataview.js

@@ -3,6 +3,7 @@
 var _ = require('underscore');
 var PSQL = require('cartodb-psql');
 var BBoxFilter = require('../models/filter/bbox');
+const CircleFilter = require('../models/filter/circle');
 var DataviewFactory = require('../models/dataview/factory');
 var DataviewFactoryWithOverviews = require('../models/dataview/overviews/factory');
 const dbParamsFromReqParams = require('../utils/database-params');
@@ -86,6 +87,9 @@ function getQueryWithFilters (dataviewDefinition, params) {
     if (params.bbox) {
         var bboxFilter = new BBoxFilter({ column: 'the_geom_webmercator', srid: 3857 }, { bbox: params.bbox });
         query = bboxFilter.sql(query);
+    } else if (params.circle) {
+        const circleFilter = new CircleFilter({ column: 'the_geom_webmercator', srid: 3857 }, { circle: params.circle });
+        query = circleFilter.sql(query);
     }
 
     return query;
@@ -197,6 +201,9 @@ function getQueryWithOwnFilters (dataviewDefinition, params) {
     if (params.bbox) {
         var bboxFilter = new BBoxFilter({ column: 'the_geom', srid: 4326 }, { bbox: params.bbox });
         query = bboxFilter.sql(query);
+    } else if (params.circle) {
+        const circleFilter = new CircleFilter({ column: 'the_geom', srid: 4326 }, { circle: params.circle });
+        query = circleFilter.sql(query);
     }
 
     return query;

lib/models/filter/circle.js

@@ -0,0 +1,58 @@
+'use strict';
+
+const debug = require('debug')('windshaft:filter:circle');
+function filterQueryTpl ({ sql, column, srid, lng, lat, radius } = {}) {
+    return `
+        SELECT
+            *
+        FROM (${sql}) _cdb_circle_filter
+        WHERE
+            ST_Intersects(
+                ${column},
+                ST_Buffer(
+                    ST_Transform(
+                        ST_SetSRID(ST_Point(${lng},${lat}), 4326),
+                        ${srid}
+                    ),
+                    ${radius}
+                )
+            )
+    `;
+}
+
+module.exports = class CircleFilter {
+    constructor (filterDefinition, filterParams) {
+        const { circle } = filterParams;
+
+        if (!circle) {
+            throw new Error('Circle filter expects to have a "circle" param');
+        }
+
+        const { lng, lat, radius } = JSON.parse(circle);
+
+        if (!Number.isFinite(lng) || !Number.isFinite(lat) || !Number.isFinite(radius)) {
+            throw new Error('Missing parameter for Circle Filter, expected: "lng", "lat", and "radius"');
+        }
+
+        this.column = filterDefinition.column || 'the_geom_webmercator';
+        this.srid = filterDefinition.srid || 3857;
+        this.lng = lng;
+        this.lat = lat;
+        this.radius = radius;
+    }
+
+    sql (rawSql) {
+        const circleSql = filterQueryTpl({
+            sql: rawSql,
+            column: this.column,
+            srid: this.srid,
+            lng: this.lng,
+            lat: this.lat,
+            radius: this.radius
+        });
+
+        debug(circleSql);
+
+        return circleSql;
+    }
+};

test/acceptance/dataviews/filters-test.js

@@ -77,8 +77,7 @@ describe('circle filter', function () {
 
     const scenarios = [
         {
-            params: {
-            },
+            params: JSON.stringify({}),
             expected: {
                 type: 'aggregation',
                 aggregation: 'sum',
@@ -99,27 +98,24 @@ describe('circle filter', function () {
         },
         {
             params: {
-                circle: {
+                circle: JSON.stringify({
                     lat: 0,
                     lng: 0,
                     radius: 5000
-                }
+                })
             },
             expected: {
                 type: 'aggregation',
                 aggregation: 'sum',
-                count: 21,
+                count: 1,
                 nulls: 0,
                 nans: 0,
                 infinities: 0,
-                min: 5,
-                max: 40,
-                categoriesCount: 4,
+                min: 1,
+                max: 1,
+                categoriesCount: 1,
                 categories: [
-                    { category: 'category_4', value: 40, agg: false },
-                    { category: 'category_3', value: 9, agg: false },
-                    { category: 'category_2', value: 6, agg: false },
-                    { category: 'category_1', value: 5, agg: false }
+                    { category: 'category_1', value: 1, agg: false }
                 ]
             }
         }

test/support/test-client.js

@@ -485,7 +485,7 @@ TestClient.prototype.getDataview = function (dataviewName, params, callback) {
                 urlParams.own_filter = params.own_filter;
             }
 
-            ['bbox', 'bins', 'start', 'end', 'aggregation', 'offset', 'categories'].forEach(function (extraParam) {
+            ['bbox', 'circle', 'bins', 'start', 'end', 'aggregation', 'offset', 'categories'].forEach(function (extraParam) {
                 if (Object.prototype.hasOwnProperty.call(params, extraParam)) {
                     urlParams[extraParam] = params[extraParam];
                 }