tiddlywiki/plugins/tiddlywiki/dom-to-image/startup.js

a non-linear personal web notebook

/*\
title: $:/plugins/tiddlywiki/dom-to-image/startup.js
type: application/javascript
module-type: startup

dom-to-image initialisation

\*/
(function(){

/*jslint node: true, browser: true */
/*global $tw: false */
"use strict";

// Export name and synchronous status
exports.name = "dom-to-image";
exports.after = ["rootwidget"];
exports.before = ["render"];
exports.synchronous = true;

exports.startup = function() {
	var getPropertiesWithPrefix = function(properties,prefix) {
		var result = Object.create(null);
		$tw.utils.each(properties,function(value,name) {
			if(name.indexOf(prefix) === 0) {
				result[name.substring(prefix.length)] = properties[name];
			}
		});
		return result;
	};
	$tw.rootWidget.addEventListener("tm-save-dom-to-image",function(event) {
		var self=this,
			params = event.paramObject || {},
			domToImage = require("$:/plugins/tiddlywiki/dom-to-image/dom-to-image-more.js"),
			domNode = document.querySelector(params.selector || "body.tc-body"),
			oncompletion = params.oncompletion,
			variables = getPropertiesWithPrefix(params,"var-");
		if(domNode) {
			var method = "toPng";
			switch(params.format) {
				case "jpeg":
				// Intentional fallthrough
				case "jpg":
					method = "toJpeg";
					break;
				case "svg":
					method = "toSvg";
					break;
			}
			domToImage[method](domNode,{
				height: $tw.utils.parseInt(params.height) || domNode.offsetHeight,
				width: $tw.utils.parseInt(params.width) || domNode.offsetWidth,
				quality: $tw.utils.parseNumber(params.quality),
				scale: $tw.utils.parseNumber(params.scale) || 1
			})
				.then(function(dataUrl) {
					// Save the image
					if(params["save-file"]) {
						var link = document.createElement("a");
						link.download = params["save-file"];
						link.href = dataUrl;
						link.click();
					}
					// Save the tiddler
					if(params["save-title"]) {
						if(dataUrl.indexOf("data:image/svg+xml;") === 0) {
							var commaIndex = dataUrl.indexOf(",");
							$tw.wiki.addTiddler(new $tw.Tiddler({
								title: params["save-title"],
								type: "image/svg+xml",
								"text": decodeURIComponent(dataUrl.substring(commaIndex + 1))
							}));	
						} else {
							var parts = dataUrl.split(";base64,");
							$tw.wiki.addTiddler(new $tw.Tiddler({
								title: params["save-title"],
								type: parts[0].split(":")[1],
								"text": parts[1]
							}));	
						}
					}
					self.wiki.invokeActionString(oncompletion,self,variables,{parentWidget: $tw.rootWidget});
				})
				.catch(function(error) {
					console.error("oops, something went wrong!", error);
				});
		}
	});
};

})();