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所以我的角度工厂有一个问题,我已经尝试解决了一段时间。我想我的角度知识在这里还不够。

我将在此处发布的大部分代码都是来自我没有编写的解决方案的另一部分的重用代码。所以这可能是我无法弄清楚的原因。这也是我做过的第一家工厂。

(function () {
'use strict';

angular.module('app.coordinate-transformer-service', [])
    .factory('coordinateTransformerService', coordinateTransformerService);

coordinateTransformerService.$inject = ['proj4js', 'gmaps'];

function coordinateTransformerService(proj4js, gmaps, objectsEpsgCode) {

    var factory = {};

    factory.$get = ['proj4js', function coordinateTransformerFactory(proj4js) {
        return new coordinateTransformerService(proj4js, gmaps, objectsEpsgCode);
    }];

    var mapProjection = 'EPSG:4326', // WGS84 latlong
            objectsProjection = 'EPSG:' + objectsEpsgCode,
            transformCoordinatesToLatLng = function (point) {
                if (objectsProjection === mapProjection) {
                    return new gmaps.LatLng(point.y, point.x);
                }

                var newPoint = {
                    x: point.x,
                    y: point.y
                };
                proj4js.transform(new proj4js.Proj(objectsProjection), new proj4js.Proj(mapProjection), newPoint);
                return new gmaps.LatLng(newPoint.y, newPoint.x);
            };

    factory.transformLatLngToProject = function (latlng) {
        if (!factory.isFunction(latlng.lng) || !factory.isFunction(latlng.lat)) {
            throw new Error("No functions lat() or lng() exists on parameter latlng");
        }

        var newPoint = {
            x: latlng.lng(),
            y: latlng.lat()
        };

        proj4js.transform(new proj4js.Proj(mapProjection), new proj4js.Proj(objectsProjection), newPoint);
        newPoint = roundPointsToCorrectDecimals(newPoint);

        return newPoint;
    };

    factory.roundPointsToCorrectDecimals = function (point) {
        var noDecimals = objectsEpsgCode === 4326 ? 5 : 0;

        if (!point || !point.x || !point.y) {
            throw new Error("Point, x or y is null or not defined");
        }

        return {
            x: point.x.toFixed(noDecimals),
            y: point.y.toFixed(noDecimals)
        };
    };

    factory.isFunction = function (functionToCheck) {
        var getType = {};
        return functionToCheck && getType.toString.call(functionToCheck) === '[object Function]';
    };

    return factory;
};

//coordinateTransformerService.prototype = {
//    constructor: coordinateTransformerService
//};
//return coordinateTransformerService;
})();

我收到错误“Provider 'proj4js' must return a value from $get factory method.” 老实说,我不知道我拥有的 factory.$get 函数是做什么的。那是我没有写的代码的一部分。Proj4js 是一个将坐标从一个系统转换到另一个系统的库。所以我们从服务器加载对象以在谷歌地图上显示它们,其中一些不使用纬度经度。所以这就是为什么我们需要用 proj4js 转换它们。如果该信息对任何人都有帮助。

但我知道工厂方法需要返回一个对象。但我不是已经这样做了吗?也许是那个 factory.$get 函数是问题所在,正如我所说我不知道​​它的目的......但删除它并没有帮助^^

另外,不要介意它被称为 coodinateTransformerService 而不是 coordinateTransformerFactory。我首先使用了一项服务,只是在我让它工作之前不想重命名它。

编辑:这可能会有所帮助。在引发错误的 angular.js 中:

function enforceReturnValue(name, factory) {
return function enforcedReturnValue() {
  var result = instanceInjector.invoke(factory, this, undefined, name);
  if (isUndefined(result)) {
    throw $injectorMinErr('undef', "Provider '{0}' must return a value from $get factory method.", name);
  }
  return result;
};
}

结果未定义。名称是 proj4js,工厂是同事制作的:

(function () {
'use strict';

angular.module('blocks.proj4js').factory('proj4js', proj4jsFactory);

proj4jsFactory.$inject = ['$window'];
function proj4jsFactory($window) {
    return $window.proj4js;
}
})();
4

1 回答 1

1

正如我所见,您将服务和提供者混为一谈。满足您的需求的最简单方法是:

angular.module('app.coordinate-transformer-service', [])
    .service('coordinateTransformerService', CoordinateTransformerService);

CoordinateTransformerService.$inject = ['proj4js', 'gmaps', 'objectsEpsgCode'];

function CoordinateTransformerService(proj4js, gmaps, objectsEpsgCode) {

    var mapProjection = 'EPSG:4326', // WGS84 latlong
            objectsProjection = 'EPSG:' + objectsEpsgCode,
            transformCoordinatesToLatLng = function (point) {
                if (objectsProjection === mapProjection) {
                    return new gmaps.LatLng(point.y, point.x);
                }

                var newPoint = {
                    x: point.x,
                    y: point.y
                };
                proj4js.transform(new proj4js.Proj(objectsProjection), new proj4js.Proj(mapProjection), newPoint);
                return new gmaps.LatLng(newPoint.y, newPoint.x);
            };

    this.transformLatLngToProject = function (latlng) {
        if (!this.isFunction(latlng.lng) || !this.isFunction(latlng.lat)) {
            throw new Error("No functions lat() or lng() exists on parameter latlng");
        }

        var newPoint = {
            x: latlng.lng(),
            y: latlng.lat()
        };

        proj4js.transform(new proj4js.Proj(mapProjection), new proj4js.Proj(objectsProjection), newPoint);
        newPoint = roundPointsToCorrectDecimals(newPoint);

        return newPoint;
    };

    this.roundPointsToCorrectDecimals = function (point) {
        var noDecimals = objectsEpsgCode === 4326 ? 5 : 0;

        if (!point || !point.x || !point.y) {
            throw new Error("Point, x or y is null or not defined");
        }

        return {
            x: point.x.toFixed(noDecimals),
            y: point.y.toFixed(noDecimals)
        };
    };

    this.isFunction = function (functionToCheck) {
        var getType = {};
        return functionToCheck && getType.toString.call(functionToCheck) === '[object Function]';
    };
};
于 2015-05-26T07:46:45.633 回答