Add ToGeohash and FromGeohash operations

src/core/config/Categories.json

@@ -53,7 +53,9 @@
             "To MessagePack",
             "From MessagePack",
             "To Braille",
-            "From Braille"
+            "From Braille",
+            "To Geohash",
+            "From Geohash"
         ]
     },
     {

src/core/operations/FromGeohash.mjs

@@ -0,0 +1,45 @@
+/**
+ * @author gchq77703 []
+ * @copyright Crown Copyright 2018
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import geohash from "ngeohash";
+
+/**
+ * From Geohash operation
+ */
+class FromGeohash extends Operation {
+
+    /**
+     * FromGeohash constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "From Geohash";
+        this.module = "Default";
+        this.description = "Converts Geohash strings into Lat / Long coordinates.  For example, <code>ww8p1r4t8</code> becomes <code>37.8324,112.5584</code>.";
+        this.infoURL = "https://en.wikipedia.org/wiki/Geohash";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        return input.split("\n").map(line => {
+            const coords = geohash.decode(line);
+            return [coords.latitude, coords.longitude].join(",");
+        }).join("\n");
+    }
+
+}
+
+export default FromGeohash;

src/core/operations/ToGeohash.mjs

@@ -0,0 +1,53 @@
+/**
+ * @author gchq77703 []
+ * @copyright Crown Copyright 2018
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import geohash from "ngeohash";
+
+/**
+ * To Geohash operation
+ */
+class ToGeohash extends Operation {
+
+    /**
+     * ToGeohash constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "To Geohash";
+        this.module = "Default";
+        this.description = "Converts Lat / Long coordinates into a Geohash string.  For example, <code>37.8324,112.5584</code> becomes <code>ww8p1r4t8</code>.";
+        this.infoURL = "https://en.wikipedia.org/wiki/Geohash";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+            {
+                name: "Precision",
+                type: "number",
+                value: 9
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const [precision] = args;
+
+        return input.split("\n").map(line => {
+            line = line.replace(/ /g, "");
+            if (line === "") return "";
+            return geohash.encode(...line.split(",").map(num => parseFloat(num)), precision);
+        }).join("\n");
+    }
+
+}
+
+export default ToGeohash;