geoJSONValidation.js

// a function to validate a correctly formed geoJSON Point for a Mongoose / Mongo Schema
// can be used in a schema as Point
// The lat lng limits correspond to Google Maps' limits

export var Point = {
  type: {
    $type: String,
    match: [ /^Point$/, '{VALUE} must be Point'],
    default: 'Point'
  },
  coordinates: {
    $type: [Number],
    validate: {
      validator: function(array) {
        if (!array) { return false }
        // A point should be exactly two items
        if (array.length !== 2) { return false }
        // longitude should be first - mongo schema
        if (array[0] > 180 || array[0] < -180) { return false }
        // latitude
        if (array[1] > 85 || array[1] < -85.05115) { return false }
        return true;
      },
      message: '{VALUE} is not a correctly formed GeoJson Point object'
    }
  }
}

export var MultiPoint = {
  type: {
    $type: String,
    match: [ /^MultiPoint$/, '{VALUE} must be MultiPoint'],
    default: 'LineString'
  },
  coordinates: [{
    $type: [Number],
    validate: {
      validator: function(array) {
        if (!array) { return false }
        for (var i = 0; i < array.length; i++) {
          // A point should be exactly two items
          if (array[i].length !== 2) { return false }
          // longitude should be first - mongo schema
          if (array[i][0] > 180 || array[0] < -180) { return false }
          // latitude
          if (array[i][1] > 85 || array[1] < -85.05115) { return false }
        }
        return true;
      },
      message: '{VALUE} is not a correctly formed GeoJson MultiPoint object'
    }
  }]
}

export var LineString = {
  type: {
    $type: String,
    match: [ /^LineString$/, '{VALUE} must be LineString'],
    default: 'LineString'
  },
  coordinates: [{
    $type: [Number],
    validate: {
      validator: function(array) {
        if (!array) { return false }
        // A LineString cannot contain less than two Points
        if (array.length < 2) { return false }
        for (var i = 0; i < array.length; i++) {
          // A point should be exactly two items
          if (array[i].length !== 2) { return false }
          // longitude should be first - mongo schema
          if (array[i][0] > 180 || array[0] < -180) { return false }
          // latitude
          if (array[i][1] > 85 || array[1] < -85.05115) { return false }
        }
        return true;
      },
      message: '{VALUE} is not a correctly formed GeoJson LineString object'
    }
  }]
}

export var MultiLineString = {
  type: {
    $type: String,
    match: [ /^MultiLineString$/, '{VALUE} must be MultiLineString'],
    default: 'MultiLineString'
  },
  coordinates: [{
    $type: [[Number]],
    validate: {
      validator: function(array) {
        if (!array) { return false }
        // longitude should be first - mongo schema
        for (var i = 0; i < array.length; i++) {
          for (var j = 0; j < array[i].length; j++) {
            // A point should be exactly two items
            if (array[i][j].length !== 2) { return false }
            // longitude should be first - mongo schema
            if (array[i][j][0] > 180 || array[0] < -180) { return false }
            // latitude
            if (array[i][j][1] > 85 || array[1] < -85.05115) { return false }
          }
        }

        return true;
      },
      message: '{VALUE} is not a correctly formed GeoJson MultiLineString object'
    }
  }]
}

export var Polygon = {
  type: {
    $type: String,
    match: [ /^Polygon$/, '{VALUE} must be Polygon'],
    default: 'Polygon'
  },
  coordinates: [{
    $type: [[Number]],
    validate: {
      validator: function(array) {
        if (!array) { return false }
        // A point should be exactly two items
        if (array.length < 2) { return false }
        // longitude should be first - mongo schema
        for (var i = 0; i < array.length; i++) {
          // The LinearRing elements should have at least four Points
          if (array[i].length < 4) { return false }
          // the LinearRing objects should have identical start and end values
          if (array[i][0] !== array[i][array.length-1]) { return false }
          for (var j = 0; j < array[i].length; j++) {
            // A point should be exactly two items
            if (array[i][j].length !== 2) { return false }
            // longitude should be first - mongo schema
            if (array[i][j][0] > 180 || array[0] < -180) { return false }
            // latitude
            if (array[i][j][1] > 85 || array[1] < -85.05115) { return false }
          }
        }

        return true;
      },
      message: '{VALUE} is not a correctly formed GeoJson Polygon object'
    }
  }]
}

// Usage:
var GeoJSONSchema = new mongoose.schema({
  point: Point,
  multipoint: MultiPoint,
  linestring: LineString,
  multilinestring: MultiLineString,
  polygon: Polygon
});

The MultiLineString and MultiPoint have not been fully tested