Initial support for TopoJSON (#79)

Does not include any attributes in the format

app/controllers/app.js

@@ -79,7 +79,7 @@ function sanitize_filename(filename) {
 // request handlers
 function handleQuery(req, res) {
 
-    var supportedFormats = ['json', 'geojson', 'csv', 'svg', 'shp', 'kml'];
+    var supportedFormats = ['json', 'geojson', 'topojson', 'csv', 'svg', 'shp', 'kml'];
     var svg_width  = 1024.0;
     var svg_height = 768.0;
 
@@ -187,7 +187,7 @@ function handleQuery(req, res) {
                 }
 
                 // TODO: refactor formats to external object
-                if (format === 'geojson'){
+                if (format === 'geojson' || format === 'topojson' ){
                     sql = ['SELECT *, ST_AsGeoJSON(the_geom,',dp,') as the_geom FROM (', sql, ') as foo'].join("");
                 } else if (format === 'shp') {
                     return null;
@@ -255,7 +255,9 @@ function handleQuery(req, res) {
 
                 // TODO: refactor formats to external object
                 if (format === 'geojson'){
-                    toGeoJSON(result, res, this);
+                    toGeoJSON(result, gn, this);
+                } else if (format === 'topojson'){
+                    toTopoJSON(result, gn, this);
                 } else if (format === 'svg'){
                     toSVG(result.rows, gn, this);
                 } else if (format === 'csv'){
@@ -299,7 +301,7 @@ function handleCacheStatus(req, res){
 }
 
 // helper functions
-function toGeoJSON(data, res, callback){
+function toGeoJSON(data, gn, callback){
     try{
         var out = {
             type: "FeatureCollection",
@@ -312,9 +314,9 @@ function toGeoJSON(data, res, callback){
                 properties: { },
                 geometry: { }
             };
-            geojson.geometry = JSON.parse(ele["the_geom"]);
+            geojson.geometry = JSON.parse(ele[gn]);
-            delete ele["the_geom"];
+            delete ele[gn];
-            delete ele["the_geom_webmercator"];
+            delete ele["the_geom_webmercator"]; // TODO: use skipfields
             geojson.properties = ele;
             out.features.push(geojson);
         });
@@ -326,6 +328,19 @@ function toGeoJSON(data, res, callback){
     }
 }
 
+function toTopoJSON(data, gn, callback){
+  toGeoJSON(data, gn, function(err, geojson) {
+    if ( err ) {
+      callback(err, null);
+      return;
+    }
+    var TopoJSON = require('topojson');
+    // TODO: provide some identifiers here
+    var topology = TopoJSON.topology(geojson.features);
+    callback(err, topology);
+  });
+}
+
 function toSVG(rows, gn, callback){
 
     var radius = 5; // in pixels (based on svg_width and svg_height)
@@ -734,6 +749,9 @@ function getContentDisposition(format, filename, inline) {
     if (format === 'geojson'){
         ext = 'geojson';
     }
+    else if (format === 'topojson'){
+        ext = 'topojson';
+    }
     else if (format === 'csv'){
         ext = 'csv';
     }

doc/API.md

@@ -12,7 +12,7 @@ Supported query string parameters:
 
   'format':   Specifies which format to use for the response.
               Supported formats: JSON (the default), GeoJSON,
-              CSV, SVG, SHP
+              TopoJSON, CSV, SVG, SHP
 
   'filename': Sets the filename to use for the query result 
               file attachment
@@ -22,7 +22,7 @@ Supported query string parameters:
               in output. Only useful with "SELECT *" queries.
 
   'dp':       Number of digits after the decimal point.
-              Only affects format=GeoJSON.
+              Only affects format GeoJSON, TopoJSON, SVG.
               By default this is 6.
 
   'api_key':  Needed to authenticate in order to modify the database.
@@ -88,7 +88,7 @@ The GeoJSON response is follows:
     }
 ```
 
-TODO: csv, kml responses
+TODO: csv, kml, svg, topojson responses
 
 Response errors
 ---------------

npm-shrinkwrap.json

@@ -186,12 +186,7 @@
     },
     "pg": {
       "version": "0.8.7-cdb1",
-      "from": "git://github.com/CartoDB/node-postgres.git#cdb_production",
+      "from": "git://github.com/CartoDB/node-postgres.git#cdb_production"
-      "dependencies": {
-        "generic-pool": {
-          "version": "1.0.9"
-        }
-      }
     },
     "generic-pool": {
       "version": "1.0.12"
@@ -205,6 +200,19 @@
     "step": {
       "version": "0.0.5"
     },
+    "topojson": {
+      "version": "0.0.8",
+      "dependencies": {
+        "optimist": {
+          "version": "0.3.5",
+          "dependencies": {
+            "wordwrap": {
+              "version": "0.0.2"
+            }
+          }
+        }
+      }
+    },
     "oauth-client": {
       "version": "0.2.0",
       "dependencies": {

package.json

@@ -18,6 +18,7 @@
         "redis": "0.7.1",
         "hiredis": "*",
         "step": "0.0.x",
+        "topojson": "~0.0.8",
         "oauth-client": "0.2.0",
         "node-uuid":"1.3.3",
         "strftime":"~0.4.7",
@@ -29,7 +30,7 @@
         "libxmljs": "~0.6.1"
     },
     "scripts": {
-        "test": "test/run_tests.sh ${RUNTESTFLAGS} test/unit/redis_pool.test.js test/unit/metadata.test.js test/unit/oauth.test.js test/unit/psql.test.js test/acceptance/app.test.js  test/acceptance/app.auth.test.js"
+        "test": "test/run_tests.sh ${RUNTESTFLAGS} test/unit/redis_pool.test.js test/unit/metadata.test.js test/unit/oauth.test.js test/unit/psql.test.js test/acceptance/app.test.js  test/acceptance/app.auth.test.js test/acceptance/export/topojson.js"
     },
     "engines": { "node": ">= 0.4.1 < 0.9" }
 }

test/acceptance/export/topojson.js

@@ -0,0 +1,113 @@
+require('../../helper');
+require('../../support/assert');
+
+
+var app    = require(global.settings.app_root + '/app/controllers/app')
+    , assert = require('assert')
+    , querystring = require('querystring')
+    , _ = require('underscore')
+    , zipfile = require('zipfile')
+    , fs      = require('fs')
+    , libxmljs = require('libxmljs')
+    ;
+
+// allow lots of emitters to be set to silence warning
+app.setMaxListeners(0);
+
+
+suite('export.topojson', function() {
+
+// TOPOJSON tests
+
+test('GET two polygons sharing an edge as topojson', function(done){
+    assert.response(app, {
+        url: '/api/v1/sql?' + querystring.stringify({
+          q: "SELECT 1 as cartodb_id, 'POLYGON((-5 0,5 0,0 5,-5 0))'::geometry as the_geom " +
+             " UNION ALL " +
+             "SELECT 2 as cartodb_id, 'POLYGON((0 -5,0 5,-5 0,0 -5))'::geometry as the_geom ",
+          format: 'topojson'
+        }),
+        headers: {host: 'vizzuality.cartodb.com'},
+        method: 'GET'
+    },{ }, function(res){
+        assert.equal(res.statusCode, 200, res.body);
+        var cd = res.header('Content-Disposition');
+        assert.equal(true, /^attachment/.test(cd), 'TOPOJSON is not disposed as attachment: ' + cd);
+        assert.equal(true, /filename=cartodb-query.topojson/gi.test(cd));
+        var topojson = JSON.parse(res.body);
+        assert.equal(topojson.type, 'Topology');
+        
+        // Check transform
+        assert.ok(topojson.hasOwnProperty('transform'));
+        var trans = topojson.transform;
+        assert.equal(_.keys(trans).length, 2); // only scale and translate
+        assert.equal(trans.scale.length, 2); // scalex, scaley
+        assert.equal(Math.round(trans.scale[0]*1e6), 1000); 
+        assert.equal(Math.round(trans.scale[1]*1e6), 1000);
+        assert.equal(trans.translate.length, 2); // translatex, translatey
+        assert.equal(trans.translate[0], -5);
+        assert.equal(trans.translate[1], -5);
+
+        // Check objects
+        assert.ok(topojson.hasOwnProperty('objects'));
+        assert.equal(_.keys(topojson.objects).length, 2);
+        var obj = topojson.objects[0];
+        //console.dir(obj);
+        // Expected: { type: 'Polygon', arcs: [ [ 0, 1 ] ] }
+        assert.equal(_.keys(obj).length, 2); // only type and arcs, no props
+        assert.equal(obj.type, 'Polygon');
+        assert.equal(obj.arcs.length, 1); /* only shell, no holes */
+        var shell = obj.arcs[0];
+        assert.equal(shell.length, 2); /* one shared arc, one non-shared */
+        assert.equal(shell[0], 0); /* shared arc */
+        assert.equal(shell[1], 1); /* non-shared arc */
+        obj = topojson.objects[1];
+        //console.dir(obj);
+        // Expected: { type: 'Polygon', arcs: [ [ 0, 2 ] ] }
+        assert.equal(_.keys(obj).length, 2); // only type and arcs, no props
+        assert.equal(obj.type, 'Polygon');
+        assert.equal(obj.arcs.length, 1); /* only shell, no holes */
+        shell = obj.arcs[0];
+        assert.equal(shell.length, 2); /* one shared arc, one non-shared */
+        assert.equal(shell[0], 0); /* shared arc */
+        assert.equal(shell[1], 2); /* non-shared arc */
+
+        // Check arcs
+        assert.ok(topojson.hasOwnProperty('arcs'));
+        assert.equal(topojson.arcs.length, 3); // one shared, two non-shared 
+        var arc = topojson.arcs[0]; // shared arc
+        assert.equal(arc.length, 2); // shared arc has two vertices
+        var p = arc[0];
+        assert.equal(Math.round(p[0]*trans.scale[0]), 0); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), 5); 
+        p = arc[1];
+        assert.equal(Math.round(p[0]*trans.scale[0]), 5); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), 5); 
+        arc = topojson.arcs[1]; // non shared arc
+        assert.equal(arc.length, 3); // non shared arcs have three vertices
+        p = arc[0];
+        assert.equal(Math.round(p[0]*trans.scale[0]), 5); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), 10); 
+        p = arc[1];
+        assert.equal(Math.round(p[0]*trans.scale[0]), 5); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), -5); 
+        p = arc[2];
+        assert.equal(Math.round(p[0]*trans.scale[0]), -10); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), 0); 
+        arc = topojson.arcs[2]; // non shared arc
+        assert.equal(arc.length, 3); // non shared arcs have three vertices
+        p = arc[0];
+        assert.equal(Math.round(p[0]*trans.scale[0]), 5); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), 10); 
+        p = arc[1];
+        assert.equal(Math.round(p[0]*trans.scale[0]), 0); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), -10); 
+        p = arc[2];
+        assert.equal(Math.round(p[0]*trans.scale[0]), -5); 
+        assert.equal(Math.round(p[1]*trans.scale[1]), 5); 
+
+        done();
+    });
+});
+
+});