Added first version of QR code generator plugin

plugins/tiddlywiki/qrcode/makeqr.js

@@ -0,0 +1,74 @@
+/*\
+title: $:/plugins/tiddlywiki/qrcode/makeqr.js
+type: application/javascript
+module-type: macro
+
+Macro to convert a string into a QR Code
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Information about this macro
+*/
+
+var qrcode = require("$:/plugins/tiddlywiki/qrcode/qrcode.js");
+
+var QRCODE_GENERATION_ERROR_PREFIX = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 300 300"><text x="0" y="30" fill="red" font-family="Helvetica, sans-serif" font-size="18">',
+	QRCODE_GENERATION_ERROR_SUFFIX = '</text></svg>';
+
+exports.name = "makeqr";
+
+exports.params = [
+	{name: "text"},
+	{name: "size"},
+	{name: "errorCorrectLevel"},
+	{name: "fallback"}
+];
+
+/*
+Run the macro
+*/
+exports.run = function(text,size,errorCorrectLevel,fallback) {
+	var result;
+	try {
+		result = generateQrCode(text,{size: size, errorCorrectLevel: errorCorrectLevel});
+	} catch (ex) {
+		console.log("makeqr error: " + ex);
+		result = fallback || ("data:image/svg+xml," + encodeURI(QRCODE_GENERATION_ERROR_PREFIX + ex + QRCODE_GENERATION_ERROR_SUFFIX));
+	}
+	return result || "";
+};
+
+function generateQrCode(text,options) {
+	options = options || {};
+	var typeNumber = options.typeNumber || 4,
+		errorCorrectLevel = options.errorCorrectLevel || "M",
+		size = options.size || 500,
+		qr;
+	try {
+		qr = qrcode(typeNumber,errorCorrectLevel);
+		qr.addData(text);
+		qr.make();
+	} catch (e) {
+		if(typeNumber >= 40) {
+			throw new Error("Text too long to encode");
+		} else {
+			return generateQrCode(text, {
+				size: size,
+				errorCorrectLevel: errorCorrectLevel,
+				typeNumber: typeNumber + 1
+			});
+		}
+	}
+	var cellsize = parseInt(size / qr.getModuleCount()),
+		margin = parseInt((size - qr.getModuleCount() * cellsize) / 2);
+	return qr.createImgTag(cellsize, margin, size);
+}
+
+
+})();