我正在尝试使用 ArcGIS JavaScript API在 Angular 应用程序中。如我所见,它使用 Dojo。所以,我正在尝试从 Angular 指令初始化 ArcGIS,如下所示:
link: function (scope, element, attrs) {
dojo.require('esri.map');
var init = function () {
console.log('dojo is ready');
var map = new esri.Map("map-container", {
center: [-111.3797, 56.7266 ],
zoom: 16,
basemap: "streets"
});
map.enableScrollWheelZoom()
};
dojo.addOnLoad(init);
}
看起来这种方式不是 100% 正确,因为当我尝试通过滚动鼠标滚轮进行缩放时,出现了这个错误:
Uncaught TypeError: Cannot call method 'apply' of null
我的问题是如何正确地将 ArcGIS 功能注入(inject)到 Angular 应用程序中?
最佳答案
我认为对此的一种非常“AngularJS”风格的方法类似于以下内容。 (在这里摆弄http://jsfiddle.net/technicolorenvy/2Ke62/4/)
我喜欢使用 angular-ui-router
,但这种方法也适用于 Angular 的 $routeProvider
。这里的魔力在于 resolve 对象,它可以选择“等待”直到 promise 得到解决,然后再继续。
angular.module('webApp', ['ui.router'])
// module (app) config
.config(function ($stateProvider, $urlRouterProvider) {
$urlRouterProvider.otherwise('/map');
$stateProvider.state('map', {
url: '/map',
template: '<div id="map"></div>',
controller: 'MapCtrl',
resolve: {
promiseObj: function ($q, $rootScope, wish) {
var deferred = $q.defer(),
deps = {
Map: 'esri/map',
FeatureLayer: 'esri/layers/FeatureLayer',
InfoTemplate: 'esri/InfoTemplate',
SimpleFillSymbol: 'esri/symbols/SimpleFillSymbol',
SimpleRenderer: 'esri/renderers/SimpleRenderer',
SimpleMarkerSymbol: 'esri/symbols/SimpleMarkerSymbol',
ScaleDependentRenderer: 'esri/renderers/ScaleDependentRenderer',
Color: 'dojo/_base/Color'
};
wish.loadDependencies(deps, function () {
deferred.resolve();
if (!$rootScope.$$phase) {
$rootScope.$apply();
}
});
return deferred.promise;
}
}
});
});
正如您在上面看到的,我们有一个 map
状态,它有一个 resolve
属性。然后,您可以构建一个代表您的 ArcGIS/Dojo 依赖项的对象,并将其传递给您的 wish.loadDependencies
(见下文)。
使用 q
我们将返回一个 promise ,一旦所有依赖项都通过 dojo 的 require
angular.module('webApp')
// service that deals w/ our dojo require
.service('wish', function () {
// it's not require... it's a wish?
var wish = {};
function _loadDependencies(deps, next) {
var reqArr = _.values(deps),
keysArr = _.keys(deps);
// use the dojo require (required by arcgis + dojo) && save refs
// to required obs
require(reqArr, function () {
var args = arguments;
_.each(keysArr, function (name, idx) {
wish[name] = args[idx];
});
next();
});
}
return {
loadDependencies: function (deps, next) {
_loadDependencies(deps, next);
},
get: function () {
return wish;
}
};
});
之后,在您的 MapCtrl
中,您可以通过在 deps
对象中使用的键直接调用所有 ArcGIS/Dojo fns(就像您通常那样)这是在应用程序配置期间构建的,因为它们现在附加到 wish.get()
返回的对象。
以下是此处示例的修改版本 (https://developers.arcgis.com/en/javascript/jssamples/renderer_proportional_scale_dependent.html)
angular.module('webApp')
// our map controller
.controller('MapCtrl', function ($rootScope, $scope, wish) {
var w = wish.get(),
greenFill = new w.Color([133, 197, 133, 0.75]),
greenOutline = new w.Color([133, 197, 133, 0.25]),
layer,
markerSym,
renderer1,
renderer2,
CROPS_URL = 'http://services.arcgis.com/V6ZHFr6zdgNZuVG0/arcgis/rest/services/USA_County_Crops_2007/FeatureServer/0';
$scope.map = new w.Map('map', {
center: [-98.579, 39.828],
zoom: 4,
basemap: 'gray'
});
layer = new w.FeatureLayer(CROPS_URL, {
outFields: ['STATE', 'COUNTY', 'M086_07', 'AREA'],
infoTemplate: new w.InfoTemplate('${COUNTY}, ${STATE}', '<div style="font: 18px Segoe UI">The percentage of the area of the county that represents farmland is <b>${M086_07}%</b>.</div>')
});
layer.setDefinitionExpression('AREA>0.01 and M086_07>0');
markerSym = new w.SimpleMarkerSymbol();
markerSym.setColor(greenFill);
markerSym.setOutline(markerSym.outline.setColor(greenOutline));
renderer1 = new w.SimpleRenderer(markerSym);
renderer1.setProportionalSymbolInfo({
field: 'M086_07',
minSize: 1,
maxSize: 10,
minDataValue: 0,
maxDataValue: 100
});
//for the second renderer increase the dot sizes and set a backgroundFillSymbol
renderer2 = new w.SimpleRenderer(markerSym);
renderer2.setProportionalSymbolInfo({
field: 'M086_07',
minSize: 5,
maxSize: 15,
minDataValue: 0,
maxDataValue: 100
});
layer.setRenderer(new w.ScaleDependentRenderer({
rendererInfos: [{
'renderer': renderer1,
'minScale': 50000000,
'maxScale': 10000000
}, {
'renderer': renderer2,
'minScale': 0,
'maxScale': 5000000
}]
}));
$scope.map.addLayer(layer);
});
演示上述代码的工作 fiddle ,可在此处找到 http://jsfiddle.net/technicolorenvy/2Ke62/4/
关于javascript - AngularJS + ArcGIS,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17547399/