terriajs/lib/Models/PolygonParameter.js

Geospatial data visualization platform.

'use strict';

/*global require*/
var defineProperties = require('terriajs-cesium/Source/Core/defineProperties');
var defined = require('terriajs-cesium/Source/Core/defined');
var FunctionParameter = require('./FunctionParameter');
var inherit = require('../Core/inherit');
var defaultValue = require('terriajs-cesium/Source/Core/defaultValue');

/**
 * A parameter that specifies an arbitrary polygon on the globe.
 *
 * @alias PolygonParameter
 * @constructor
 * @extends FunctionParameter
 *
 * @param {Object} options Object with the following properties:
 * @param {Terria} options.terria The Terria instance.
 * @param {String} options.id The unique ID of this parameter.
 * @param {String} [options.name] The name of this parameter.  If not specified, the ID is used as the name.
 * @param {String} [options.description] The description of the parameter.
 * @param {Boolean} [options.defaultValue] The default value.
 */
var PolygonParameter = function(options) {
    FunctionParameter.call(this, options);
};

inherit(FunctionParameter, PolygonParameter);

defineProperties(PolygonParameter.prototype, {
    /**
     * Gets the type of this parameter.
     * @memberof PolygonParameter.prototype
     * @type {String}
     */
    type: {
        get: function() {
            return 'polygon';
        }
    }

    /**
     * Gets or sets the value of this parameter.
     * @memberof PolygonParameter.prototype
     * @member {Number[][][]} value
     */
});

/**
 * Represents value as string.
 * @param {Object} value Value to format as string.
 * @return {String} String representing value.
 */
PolygonParameter.prototype.formatValueAsString = function(value) {
    value = defaultValue(value, this.value);
    if (!defined(value)) {
        return '-';
    }

    const pointsLongLats = value[0];

    let polygon = '';
    for (let i = 0; i < pointsLongLats.length; i++) {
        polygon += '[' + pointsLongLats[i][0].toFixed(3) + ', ' + pointsLongLats[i][1].toFixed(3) + ']';
        if (i !== pointsLongLats.length - 1) {
            polygon += ', ';
        }
    }
    if (polygon.length > 0) {
        return '[' + polygon + ']';
    } else {
        return '';
    }
};

/**
 * Get feature as geojson for display on map.
 * @param {Object} value Value to use.
 * @return GeoJson object.
 */
PolygonParameter.prototype.getGeoJsonFeature = function(value) {
    value = defaultValue(value, this.value);
    return {
                type: 'Feature',
                geometry: {
                    type: 'Polygon',
                    coordinates: value
                }
            };
};

/**
 * Process value so that it can be used in an URL.
 * @param {String} value Value to use to format.
 * @return {String} Stringified JSON that can be used to pass parameter value in URL.
 */
PolygonParameter.formatValueForUrl = function(value) {
    return JSON.stringify({
        'type': 'FeatureCollection',
        'features': [
            {
                'type': 'Feature',
                'geometry': {
                    'type': 'Polygon',
                    'coordinates': value
                }
            }
        ]
    });
};

PolygonParameter.formatValueAsString = PolygonParameter.prototype.formatValueAsString;
PolygonParameter.getGeoJsonFeature = PolygonParameter.prototype.getGeoJsonFeature;
module.exports = PolygonParameter;