平均和地理空间查询 - 查找LineStrings在其名称相交的另一个上

Question

我正在尝试使用MEAN构建一个应用程序,但现在我在尝试时遇到困难find linestrings intersecting on another one given its name.

例如,给定下面的图像,poly1并且poly2应该有交叉而poly3不是.

我们假设poly1有以下坐标和以下坐标JSON:

{ 
  "_id" : ObjectId("57ab2107505ab11b1bd8422e"), 
  "name" : "poly1", 
  "updated_at" : ISODate("2016-08-10T12:41:43.789+0000"), 
  "created_at" : ISODate("2016-08-10T12:41:43.780+0000"), 
  "geo" : {
      "coordinates" : [ [14.59, 24.847], [28.477, 15.961] ], 
      "type" : "LineString"
  }, 
  "__v" : NumberInt(0)
}

当我运行的查询上MongoChef,我觉得都poly1和poly2我不觉得poly3像我想:

{
    geo :{
        $geoIntersects:{
            $geometry :{
                type: "LineString" ,
                coordinates: [ [14.59, 24.847], [28.477, 15.961] ]
            }
        }
    }
}

虽然,当我运行查询Mongoose给定一个Polyline Id/name它不起作用

//Given
var linestringById = Linestrings.find({name : lineName});
var linestrings    = Linestrings.find({});    

//Works
query = linestrings.where({ geo : { $geoIntersects : 
                    { $geometry : 
                       { type : 'LineString', 
                         coordinates : [ [27.528, 25.006], [14.063, 15.591] ]
                        } 
                     } } });

//Does not work
query = linestrings.where({ geo : { $geoIntersects : 
                   { $geometry : 
                     { type : 'LineString', 
                       coordinates : linestringById.geo.coordinates
                     } 
                    } } });
//Also does not work:
query = linestrings.where({ geo : { $geoIntersects : 
                   { $geometry : 
                     { type : 'LineString', 
                       coordinates : linestringById
                     } 
                    } } });

这是LineStrings的Schema:

var mongoose = require('mongoose');
var Schema   = mongoose.Schema;

// Creates a LineString Schema.
var linestrings = new Schema({
    name: {type: String, required : true},
    geo : {
        type : {type: String, default: "LineString"},
                coordinates : Array
    },
    created_at: {type: Date, default: Date.now},
    updated_at: {type: Date, default: Date.now}
});

// Sets the created_at parameter equal to the current time
linestrings.pre('save', function(next){
    now = new Date();
    this.updated_at = now;
    if(!this.created_at) {
        this.created_at = now
    }
    next();
});

linestrings.index({geo : '2dsphere'});
module.exports = mongoose.model('linestrings', linestrings);

这就是我从前端QueryController.js调用查询的方法

/** Looks for LineStrings intersecting a given linestring **/
vm.polyIntersect = function () {

   //Taking name from a form
   vm.queryBody = {
                    name : vm.formData.poly1
   };

   // Post the queryBody 
   $http.post('/find-poly-intersection', vm.queryBody)
             .success(function(queryResults) {
                console.log(queryResults);
             })
            .error(function(queryResults) {
                console.log('Error: no results found '+queryResults));
            });
};

这是我的Route.js:

/** Requiring Factories **/
var LinestringFactory = require('./factories/linestring.factory.js');

module.exports = function(app) {
  // Retrieves JSON records for all linestrings intersecting a given one
    app.post('/find-poly-intersection', function(req, res) {
        LinestringFactory.findIntersections(req).then( function (linestrings) {
            return res.json(linestrings);
        }, function (error) {
            return res.json(error);
        })
    });
}

这是我的LineString.factory.js:

var Linestrings  = require('../models/linestring-model.js');

exports.findIntersections = findIntersections;

/** Finds Linestrings Intersections **/
function findIntersections(req) {
    return new Promise( function (resolve, reject) {
        var lineName       = req.body.name;
        var linestringById = Linestrings.find({name : lineName});
        var linestrings    = Linestrings.find({});

        //Check if that certain linestring exists with Lodash
        if (_.isEmpty(linestringById) || _.isUndefined(linestringById) 
            || _.isNull(linestringById)){
            return reject('No Linestrings found for that Name');
        } else {

        query = linestrings.where({ geo : 
                { $geoIntersects : { $geometry : 
                  { type : 'LineString', 
                    coordinates : linestringById.geo.coordinates} 
                } } });

        query.exec(function (err, intersections) {
            if (err){
                return reject(err);
            }
            return resolve(intersections);
        });

    }, function (error) {
        return reject(error);
    })
}

console.login QueryController总是给我Object {}任何线串名称.

这是查询的Mongoose日志.

我确保插入[lng, lat]坐标

你有没有想过为什么我找不到任何与Id交叉的LineString,而我可以使用直线坐标找到它们？

提前致谢.

Answer 1

我终于用下面的代码解决了这个问题

/** Finds Linestrings Intersections **/
function findIntersections(req) {
    return new Promise( function (resolve, reject) {
        var lineName = req.body.name;
        Linestrings.findOne({name : lineName}).then( function (linestringById, error) {
            if(error){
                return reject({error : 'LineString not Found'});
            }
                queryIntersections(linestringById).then( function (response) {
                    return resolve(response);
                });
        });
    }, function (error) {
        return reject({error : 'Error while executing promise'});
    });
}

function queryIntersections(linestringById) {
    return new Promise( function (resolve, reject) {
        if (_.isEmpty(linestringById) || _.isUndefined(linestringById) || _.isNull(linestringById)){
            return reject({ error : 'No Linestrings found for that Name'});
        } else {
            query = Linestrings.where( { geo : { $geoIntersects : { $geometry : { type: 'LineString', coordinates: linestringById.geo.coordinates  } } } } );
            queryExec(query).then( function (intersections) {
                return resolve(intersections);
            });
        }
    }, function (error){
       return reject({error : 'Error while executing promise'});
    });
}

该错误是由于我没有正确传递linestrings和linestringById对象到查询而引起的。

我希望它能帮助某人。