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An AngularJS Service for intelligently geocoding addresses using Google's API. Makes use of localStorage (via the ngStorage package) to avoid unnecessary trips to the server. Queries Google's API synchronously to avoid `google.maps.GeocoderStatus.OVER_QUERY_LIMIT`
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| /*global angular: true, google: true, _ : true */ | |
| 'use strict'; | |
| angular.module('geocoder', ['ngStorage']).factory('Geocoder', function ($localStorage, $q, $timeout) { | |
| var locations = $localStorage.locations ? JSON.parse($localStorage.locations) : {}; | |
| var queue = []; | |
| // Amount of time (in milliseconds) to pause between each trip to the | |
| // Geocoding API, which places limits on frequency. | |
| var queryPause = 250; | |
| /** | |
| * executeNext() - execute the next function in the queue. | |
| * If a result is returned, fulfill the promise. | |
| * If we get an error, reject the promise (with message). | |
| * If we receive OVER_QUERY_LIMIT, increase interval and try again. | |
| */ | |
| var executeNext = function () { | |
| var task = queue[0], | |
| geocoder = new google.maps.Geocoder(); | |
| geocoder.geocode({ address : task.address }, function (result, status) { | |
| if (status === google.maps.GeocoderStatus.OK) { | |
| var latLng = { | |
| lat: result[0].geometry.location.lat(), | |
| lng: result[0].geometry.location.lng() | |
| }; | |
| queue.shift(); | |
| locations[task.address] = latLng; | |
| $localStorage.locations = JSON.stringify(locations); | |
| task.d.resolve(latLng); | |
| if (queue.length) { | |
| $timeout(executeNext, queryPause); | |
| } | |
| } else if (status === google.maps.GeocoderStatus.ZERO_RESULTS) { | |
| queue.shift(); | |
| task.d.reject({ | |
| type: 'zero', | |
| message: 'Zero results for geocoding address ' + task.address | |
| }); | |
| } else if (status === google.maps.GeocoderStatus.OVER_QUERY_LIMIT) { | |
| queryPause += 250; | |
| $timeout(executeNext, queryPause); | |
| } else if (status === google.maps.GeocoderStatus.REQUEST_DENIED) { | |
| queue.shift(); | |
| task.d.reject({ | |
| type: 'denied', | |
| message: 'Request denied for geocoding address ' + task.address | |
| }); | |
| } else if (status === google.maps.GeocoderStatus.INVALID_REQUEST) { | |
| queue.shift(); | |
| task.d.reject({ | |
| type: 'invalid', | |
| message: 'Invalid request for geocoding address ' + task.address | |
| }); | |
| } | |
| }); | |
| }; | |
| return { | |
| latLngForAddress : function (address) { | |
| var d = $q.defer(); | |
| if (_.has(locations, address)) { | |
| $timeout(function () { | |
| d.resolve(locations[address]); | |
| }); | |
| } else { | |
| queue.push({ | |
| address: address, | |
| d: d | |
| }); | |
| if (queue.length === 1) { | |
| executeNext(); | |
| } | |
| } | |
| return d.promise; | |
| } | |
| }; | |
| }); |
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