This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.ip-ddns.com/scripts/523986/1522605/GeoWKTer.js
/**
* GeoWKTer: WKT to GeoJSON Converter
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* GeoWKTer was derived from and inspired by the work of Wicket.js <https://github.com/arthur-e/Wicket>
*/
var GeoWKTer = (function () {
/**
* Constructor for GeoWKTer.
* Initializes regex patterns and prepares the converter for handling WKT strings and converting to GeoJSON.
*/
function GeoWKTer() {
this.features = [];
this.regExes = {
typeStr: /^\s*(\w+)\s*\((.*)\)\s*$/, // Matches WKT type and component strings
spaces: /\s+|\+/, // Matches spaces and plus signs for coordinate splitting
comma: /\s*,\s*/, // Matches commas, allowing for optional surrounding spaces
parenComma: /\)\s*,\s*\(/, // Matches commas between coordinate groups in WKT
};
}
/**
* Trims a specified substring from the start and end of a string.
*
* @param {string} str - The string to be trimmed.
* @param {string} sub - The substring to trim (default is whitespace).
* @returns {string} - The trimmed string.
*/
GeoWKTer.prototype.trim = function (str, sub) {
sub = sub || " ";
while (str.startsWith(sub)) {
str = str.substring(1);
}
while (str.endsWith(sub)) {
str = str.substring(0, str.length - 1);
}
return str;
};
/**
* Parses WKT strings and associates a label with each parsed geometry.
* Handles multi-line input, parsing each line as an individual WKT geometry.
*
* @param {string} wktText - The WKT string, potentially containing multiple lines.
* @param {string} label - The label to associate with each parsed geometry.
* @returns {Array} - An array of objects representing parsed WKT geometries.
*/
GeoWKTer.prototype.read = function (wktText, label) {
const lines = wktText.trim().split(/\r?\n/);
const results = lines.map((line) => {
line = line.trim();
if (line) {
const matches = this.regExes.typeStr.exec(line);
if (matches) {
const type = matches[1].toLowerCase();
const base = matches[2];
if (this.ingest[type]) {
const components = this.ingest[type].call(this, base);
// Return an object with the necessary parts and the label
return { type, components, label };
} else {
console.error("Unsupported WKT type:", type);
}
} else {
console.error("Invalid WKT string:", line);
}
}
return null; // Return null if there is an error
});
// Filter out null results in case any line was invalid
return results.filter((result) => result !== null);
};
/**
* Converts an array of parsed WKT objects into a GeoJSON FeatureCollection.
*
* @param {Array} dataArray - Array of parsed WKT objects with geometry data.
* @returns {Object} - A GeoJSON FeatureCollection object containing the features.
*/
GeoWKTer.prototype.toGeoJSON = function (dataArray) {
// Map each parsed data to a GeoJSON feature
const features = dataArray.map((data) => {
const { type, components, label } = data;
const geometry = {
type: type[0].toUpperCase() + type.slice(1).toLowerCase(),
};
if (type === "geometrycollection") {
geometry.geometries = components.map((component) => this.toGeoJSON([component]).geometry);
} else {
geometry.coordinates = components;
}
return {
type: "Feature",
geometry: geometry,
properties: {
Name: label || "", // Add the label as the Name property in GeoJSON
},
};
});
// Return a FeatureCollection containing all features
return {
type: "FeatureCollection",
features: features,
};
};
/**
* Contains methods for parsing different types of WKT geometries into coordinate arrays.
*/
GeoWKTer.prototype.ingest = {
/**
* Parses a WKT POINT into a coordinate array.
* @param {string} str - The WKT POINT string.
* @returns {Array} - An array of coordinates for the point.
*/
point: function (str) {
const coords = this.trim(str).split(this.regExes.spaces).map(Number);
return [[coords[0], coords[1]]];
},
/**
* Parses a WKT MULTIPOINT into an array of coordinate arrays.
* @param {string} str - The WKT MULTIPOINT string.
* @returns {Array} - An array containing arrays of point coordinates.
*/
multipoint: function (str) {
return str.match(/\(([^)]+)\)/g).map((point) => {
const coords = point.replace(/[()]/g, "").split(this.regExes.spaces).map(Number);
return [coords[0], coords[1]];
});
},
/**
* Parses a WKT LINESTRING into an array of coordinate arrays.
* @param {string} str - The WKT LINESTRING string.
* @returns {Array} - An array containing arrays of line coordinates.
*/
linestring: function (str) {
return str.split(this.regExes.comma).map((pair) => {
const coords = pair.trim().split(this.regExes.spaces).map(Number);
return [coords[0], coords[1]];
});
},
/**
* Parses a WKT MULTILINESTRING into an array of lines, each containing an array of coordinates.
* @param {string} str - The WKT MULTILINESTRING string.
* @returns {Array} - An array containing arrays of lines.
*/
multilinestring: function (str) {
return str.match(/\(([^)]+)\)/g).map((line) => {
return line
.replace(/[()]/g, "")
.split(this.regExes.comma)
.map((pair) => {
const coords = pair.trim().split(this.regExes.spaces).map(Number);
return [coords[0], coords[1]];
});
});
},
/**
* Parses a WKT POLYGON into an array of rings, each containing an array of coordinates.
* @param {string} str - The WKT POLYGON string.
* @returns {Array} - An array of rings with arrays of coordinates.
*/
polygon: function (str) {
return str.match(/\(([^)]+)\)/g).map((ring) => {
return ring
.replace(/[()]/g, "")
.trim()
.split(this.regExes.comma)
.map((pair) => {
const coords = pair.trim().split(this.regExes.spaces).map(Number);
return [coords[0], coords[1]];
});
});
},
/**
* Parses a WKT MULTIPOLYGON into an array of polygons, each containing rings of coordinates.
* @param {string} str - The WKT MULTIPOLYGON string.
* @returns {Array} - An array of polygons, each containing arrays of rings with coordinates.
*/
multipolygon: function (str) {
return str.match(/\(\(([^)]+)\)\)/g).map((polygon) => {
return polygon
.replace(/^\(\(*/, "")
.replace(/\)\)*$/, "")
.split(this.regExes.parenComma)
.map((ring) => {
return ring
.trim()
.split(this.regExes.comma)
.map((pair) => {
const coords = pair.trim().split(this.regExes.spaces).map(Number);
return [coords[0], coords[1]];
});
});
});
},
/**
* Parses a WKT GEOMETRYCOLLECTION into an array of geometry objects, each with type and components.
* @param {string} str - The WKT GEOMETRYCOLLECTION string.
* @returns {Array} - An array of geometry objects each with type and components.
*/
geometrycollection: function (str) {
const cleanedStr = str.trim().replace(/^\(*/, "").replace(/\)*$/, "");
let geoms = [];
let depth = 0;
let start = 0;
for (let i = 0; i < cleanedStr.length; i++) {
if (cleanedStr[i] === "(") {
if (depth === 0) start = i;
depth++;
} else if (cleanedStr[i] === ")") {
depth--;
if (depth === 0) {
const geomStr = cleanedStr.slice(start, i + 1);
const matches = this.regExes.typeStr.exec(geomStr);
if (matches) {
const type = matches[1].toLowerCase();
const base = matches[2];
if (this.ingest[type]) {
const components = this.ingest[type].call(this, base);
geoms.push({ type, components });
} else {
console.error(`Unsupported WKT type in GeometryCollection: ${type}`);
}
}
}
}
}
return geoms;
},
};
return GeoWKTer;
})();
