Merge branch 'nellie/following' into 'master'

Adding better handling for following (+) selectors

See merge request tools/pagedjs!125

specs/following-selector/following-selector.spec.js

+const TIMEOUT = 10000; // Some book might take longer than this to renderer
+
+describe("following-selector", () => {
+	let page;
+	beforeAll(async () => {
+		page = await loadPage("following-selector/following-selector.html");
+		return page.rendered;
+	}, TIMEOUT);
+
+	afterAll(async () => {
+		if (!DEBUG) {
+			await page.close();
+		}
+	});
+
+	it("should render text", async () => {
+		let text = await page.evaluate(() => document.body.textContent);
+		expect(text).toContain("Chapter 1. Loomings.");
+	});
+
+	it("should render 14 pages", async () => {
+		let pages = await page.$$eval(".pagedjs_page", (r) => r.length);
+		expect(pages).toBe(14);
+	});
+
+	if (!DEBUG) {
+		it("should create a pdf", async () => {
+			let pdf = await page.pdf(PDF_SETTINGS);
+
+			expect(pdf).toMatchPDFSnapshot(1);
+			expect(pdf).toMatchPDFSnapshot(2);
+		});
+	}
+}
+);

src/modules/paged-media/following.js

+import Handler from "../handler";
+import csstree from "css-tree";
+import {UUID} from "../../utils/utils";
+
+class Following extends Handler {
+	constructor(chunker, polisher, caller) {
+		super(chunker, polisher, caller);
+
+		this.styleSheet = polisher.styleSheet;
+		this.selectors = {};
+	}
+
+	onRule(ruleNode, ruleItem, rulelist) {
+		let selector = csstree.generate(ruleNode.prelude);
+		if (selector.match(/\+/)) {
+			
+			let declarations = csstree.generate(ruleNode.block);
+			declarations = declarations.replace(/[{}]/g,"");
+
+			let uuid = "following-" + UUID();
+
+			selector.split(",").forEach((s) => {
+				if (!this.selectors[s]) {
+					this.selectors[s] = [uuid, declarations];
+				} else {
+					this.selectors[s][1] = `${this.selectors[s][1]};${declarations}` ;
+				}
+			});
+
+			rulelist.remove(ruleItem);
+		}
+	}
+
+	afterParsed(parsed) {
+		this.processSelectors(parsed, this.selectors);
+	}
+
+	processSelectors(parsed, selectors) {
+		// add the new attributes to matching elements
+		for (let s in selectors) {
+			let elements = parsed.querySelectorAll(s);
+
+			for (var i = 0; i < elements.length; i++) {
+				let dataFollowing = elements[i].getAttribute("data-following");
+
+				if (dataFollowing && dataFollowing != "") {
+					dataFollowing = `${dataFollowing},${selectors[s][0]}`;
+					elements[i].setAttribute("data-following", dataFollowing);
+				} else {
+					elements[i].setAttribute("data-following", selectors[s][0]);
+				}
+			}
+
+			let rule = `*[data-following*='${selectors[s][0]}'] { ${selectors[s][1]}; }`;
+			this.styleSheet.insertRule(rule, this.styleSheet.cssRules.length);
+		}
+	}
+}
+
+
+
+
+export default Following;
+

src/modules/paged-media/index.js

@@ -6,6 +6,7 @@ import Counters from "./counters";
 import Lists from "./lists";
 import PositionFixed from "./position-fixed";
 import NthOfType from "./nth-of-type";
+import Following from "./following";
 
 export default [
 	AtPage,
@@ -15,5 +16,6 @@ export default [
 	Counters,
 	Lists,
 	PositionFixed,
-	NthOfType
+	NthOfType,
+	Following
 ];