Merge pull request #55 from akesser/master

Add support for srcset

Author: hemanth

README.md

@@ -25,7 +25,15 @@ npm i -D html-loader
 
 By default every local `<img src="image.png">` is required (`require('./image.png')`). You may need to specify loaders for images in your configuration (recommended `file-loader` or `url-loader`).
 
-You can specify which tag-attribute combination should be processed by this loader via the query parameter `attrs`. Pass an array or a space-separated list of `<tag>:<attribute>` combinations. (Default: `attrs=img:src`)
+Also every `<img srcset="..."`> is converted to `require` statements. For example
+``` html
+<img src="image.jpg" srcset="image.jpg 1x, [email protected] 2x">
+```
+is converted to
+``` javascript
+"<img src=\"" + require("./image.jpg") + "\" srcset=\"" + require("./image.jpg") + " 1x," + require("./[email protected]") + " 2x \">"
+```
+You can specify which tag-attribute combination should be processed by this loader via the query parameter `attrs`. Pass an array or a space-separated list of `<tag>:<attribute>` combinations. (Default: `attrs=[img:src, img:srcset]`)
 
 To completely disable tag-attribute processing (for instance, if you're handling image loading on the client side) you can pass in `attrs=false`.
 

index.js

@@ -26,7 +26,7 @@ function getLoaderConfig(context) {
 module.exports = function(content) {
 	this.cacheable && this.cacheable();
 	var config = getLoaderConfig(this);
-	var attributes = ["img:src"];
+	var attributes = ["img:src", "img:srcset"];
 	if(config.attrs !== undefined) {
 		if(typeof config.attrs === "string")
 			attributes = config.attrs.split(" ");
@@ -38,27 +38,56 @@ module.exports = function(content) {
 			throw new Error("Invalid value to config parameter attrs");
 	}
 	var root = config.root;
-	var links = attrParse(content, function(tag, attr) {
+	var rawLinks = attrParse(content, function(tag, attr) {
 		return attributes.indexOf(tag + ":" + attr) >= 0;
 	});
+	var links = [];
+	rawLinks.forEach(function (link) {
+		var length = link.length;
+		var start = link.start;
+		var valueList = link.value.split(",");
+		valueList.forEach(function (newLink) {
+			var trimmed = newLink.trim();
+			var cLength = newLink.length;
+			var spacePos = trimmed.indexOf(" ");
+			var spaceStart = newLink.indexOf(trimmed);
+			var len = cLength+ spaceStart;
+			if (-1 != spacePos) {
+				len = spacePos + spaceStart;
+				trimmed = trimmed.substring(0,spacePos);
+			}
+			links.push({start: start, length: len , value: trimmed});
+			start += cLength+1;
+		});
+	});
 	links.reverse();
 	var data = {};
 	content = [content];
 	links.forEach(function(link) {
-		if(!loaderUtils.isUrlRequest(link.value, root)) return;
-
-		var uri = url.parse(link.value);
-		if (uri.hash !== null && uri.hash !== undefined) {
-			uri.hash = null;
-			link.value = uri.format();
-			link.length = link.value.length;
-		}
+		var newValue = link.value.split(",");
+		var newValue = newValue.map(function (value) {
+			var valueArray = value.trim().split(" ");
+			var obj = {
+				value: valueArray.shift(),
+				additional: valueArray,
+			};
+			if(!loaderUtils.isUrlRequest(obj.value, root)) return;
+			var uri = url.parse(obj.value);
+			if (uri.hash !== null && uri.hash !== undefined) {
+				obj.hash = uri.hash;
+				uri.hash = null;
+				obj.value = uri.format();
+			}
+			return obj;
+		});
 
 		do {
 			var ident = randomIdent();
 		} while(data[ident]);
-		data[ident] = link.value;
+		data[ident] = newValue;
 		var x = content.pop();
+
+
 		content.push(x.substr(link.start + link.length));
 		content.push(ident);
 		content.push(x.substr(0, link.start));
@@ -95,9 +124,16 @@ module.exports = function(content) {
 	} else {
 		content = JSON.stringify(content);
 	}
-
 	return "module.exports = " + content.replace(/xxxHTMLLINKxxx[0-9\.]+xxx/g, function(match) {
 		if(!data[match]) return match;
-		return '" + require(' + JSON.stringify(loaderUtils.urlToRequest(data[match], root)) + ') + "';
+		return data[match].reduce(function (pV,cV, index, array) {
+
+			var hash = cV.hash || "";
+			var additional = cV.additional.length != 0 ? " " + cV.additional.join(" ") : "";
+			if (index != array.length -1) {
+				additional += ",";
+			}
+			return pV + '" + require(' + JSON.stringify(loaderUtils.urlToRequest(cV.value, root)) + ') + "' + hash + additional;
+		},"");
 	}) + ";";
 }

test/loaderTest.js

@@ -29,6 +29,27 @@ describe("loader", function() {
 			'module.exports = "Text <script src=\\"" + require("./script.js") + "\\"><img src=\\"" + require("./image.png") + "\\">";'
 		);
 	});
+	it("should handle srcset-attrubute by default", function ()
+	{
+		loader.call({
+		},'Text <img srcset="image.png 1x">').should.be.eql(
+			'module.exports = "Text <img srcset=\\"" + require("./image.png") + " 1x\\">";'
+		)
+	});
+	it("should handle srcset-attrubute with comma seperated list", function ()
+	{
+		loader.call({
+		},'Text <img srcset="image.png 1x,[email protected] 2x">').should.be.eql(
+			'module.exports = "Text <img srcset=\\"" + require("./image.png") + " 1x,\" + require("./[email protected]") + " 2x\\">";'
+		)
+	});
+	it("should handle srcset-attrubute with comma seperated list, independend of spaces in list", function ()
+	{
+		loader.call({
+		},'Text <img srcset="image.png 1x,         [email protected] 2x">').should.be.eql(
+			'module.exports = "Text <img srcset=\\"" + require("./image.png") + " 1x,\" + require("./[email protected]") + " 2x\\">";'
+		)
+	});
 	it("should not make bad things with templates", function() {
 		loader.call({}, '<h3>#{number} {customer}</h3>\n<p>   {title}   </p>').should.be.eql(
 			'module.exports = "<h3>#{number} {customer}</h3>\\n<p>   {title}   </p>";'