Add imageryBlacklists function to get blacklists from OSM API

(for #3623)

modules/services/osm.js

@@ -25,6 +25,7 @@ var dispatch = d3.dispatch('authLoading', 'authDone', 'change', 'loading', 'load
     }),
     rateLimitError,
     userDetails,
+    capabilities,
     off;
 
 
@@ -161,6 +162,7 @@ export default {
     reset: function() {
         userDetails = undefined;
         rateLimitError = undefined;
+        capabilities = undefined;
         _.forEach(inflight, abortRequest);
         loadedTiles = {};
         inflight = {};
@@ -429,22 +431,54 @@ export default {
     },
 
 
+    // `status` will always request the `api/capabilities` resource..
     status: function(callback) {
-        function done(capabilities) {
+        function done(xml) {
+            capabilities = xml;
+
             if (rateLimitError) {
                 callback(rateLimitError, 'rateLimited');
             } else {
                 var apiStatus = capabilities.getElementsByTagName('status'),
                     val = apiStatus[0].getAttribute('api');
+
                 callback(undefined, val);
             }
         }
+
         d3.xml(urlroot + '/api/capabilities').get()
             .on('load', done)
             .on('error', callback);
     },
 
 
+    // `imageryBlacklists` will reuse the previous `api/capabilities` result, if available..
+    imageryBlacklists: function(callback) {
+        function done(xml) {
+            capabilities = xml;
+
+            var elements = capabilities.getElementsByTagName('blacklist'),
+                blacklists = [];
+            for (var i = 0; i < elements.length; i++) {
+                var regex = elements[i].getAttribute('regex');  // needs unencode?
+                if (regex) {
+                    blacklists.push(regex);
+                }
+            }
+
+            callback(undefined, blacklists);
+        }
+
+        if (capabilities) {
+            done(capabilities);
+        } else {
+            d3.xml(urlroot + '/api/capabilities').get()
+                .on('load', done)
+                .on('error', callback);
+        }
+    },
+
+
     tileZoom: function(_) {
         if (!arguments.length) return tileZoom;
         tileZoom = _;

test/spec/services/osm.js

@@ -445,4 +445,58 @@ describe('iD.serviceOsm', function () {
             expect(connection.changesetTags('2.0.0', '', [])).not.to.have.property('comment');
         });
     });
+
+    describe('API capabilities', function() {
+        var server,
+            capabilitiesXML = '<?xml version="1.0" encoding="UTF-8"?><osm>' +
+            '<api>' +
+            '<version minimum="0.6" maximum="0.6"/>' +
+            '<area maximum="0.25"/>' +
+            '<tracepoints per_page="5000"/>' +
+            '<waynodes maximum="2000"/>' +
+            '<changesets maximum_elements="50000"/>' +
+            '<timeout seconds="300"/>' +
+            '<status database="online" api="online" gpx="online"/>' +
+            '</api>' +
+            '<policy><imagery><blacklist regex=".*\.google(apis)?\..*/(vt|kh)[\?/].*([xyz]=.*){3}.*"/></imagery></policy>' +
+            '</osm>';
+
+
+        beforeEach(function() {
+            server = sinon.fakeServer.create();
+            // connection.reset();
+        });
+
+        afterEach(function() {
+            server.restore();
+        });
+
+        describe('#status', function() {
+            it('gets API status', function(done) {
+                connection.status(function(err, val) {
+                    expect(val).to.eql('online');
+                    done();
+                });
+
+                server.respondWith('GET', 'http://www.openstreetmap.org/api/capabilities',
+                    [200, { 'Content-Type': 'text/xml' }, capabilitiesXML]);
+                server.respond();
+            });
+        });
+
+        describe('#imageryBlacklists', function() {
+            it('gets imagery blacklists', function(done) {
+                connection.imageryBlacklists(function(err, val) {
+                    expect(val).to.eql(['.*\.google(apis)?\..*/(vt|kh)[\?/].*([xyz]=.*){3}.*']);
+                    done();
+                });
+
+                server.respondWith('GET', 'http://www.openstreetmap.org/api/capabilities',
+                    [200, { 'Content-Type': 'text/xml' }, capabilitiesXML]);
+                server.respond();
+            });
+        });
+
+    });
+
 });