fixed printing and added default options

chromium.js

@@ -105,10 +105,10 @@ class HeadlessChromium
 		return await this.runPageCommand(page, "Page.enable")
 	}
 
-	async printToPdf(page)
+	async printToPdf(page, options)
 	{
 		// wip: printing fails for some reason
-		var response = await this.runPageCommand(page, "Page.printToPDF")
-		return response
+		var response = await this.runPageCommand(page, "Page.printToPDF", options)
+		return response.data //atob(response.data)
 	}
 }

connection.js

@@ -2,7 +2,7 @@ class RequestHandler
 {
 	constructor()
 	{
-		this.buffer = ["https://www.example.com"]
+		this.buffer = ["https://www.example.com", "https://www.nexedi.com/"]
 	}
 
 	hasNextRequest()
@@ -15,8 +15,11 @@ class RequestHandler
 		return this.buffer.pop()
 	}
 
-	publishResults(data)
+	publishResults(name, data)
 	{
-		console.log("result: \n" + data)
+		var a = document.createElement("a");
+		a.href = "data:application/pdf;base64," + data;
+		a.download = `${name}.pdf`;
+		a.click();
 	}
 }
\ No newline at end of file

index.html

@@ -7,6 +7,33 @@
 		<script src="connection.js"></script>
 		<script src="chromium.js"></script>
 		<script>
+			function mm2inches (mm)
+			{
+				return mm / 25.4
+			}
+
+			/*
+			Options for printing:
+			https://chromedevtools.github.io/devtools-protocol/1-3/Page/#method-printToPDF
+			*/
+			var optionsForPrintToPdf =
+			{
+				landscape: true,
+				displayHeaderFooter: false,
+				printBackground: true,
+				scale: 1,
+				paperWidth: mm2inches(297 /* millimetre */),
+				paperHeight: mm2inches(210 /* millimetre */),
+				marginTop: mm2inches(10 /* millimetre */),
+				marginBottom: mm2inches(10 /* millimetre */),
+				marginLeft: mm2inches(10 /* millimetre */),
+				marginRight: mm2inches(10 /* millimetre */),
+				pageRanges: "",
+				headerTemplate: "",
+				footerTemplate: "",
+				preferCSSPageSize: false
+			}
+
 			/*
 			Usage: Start google chromium with the following command line flags.
 				--headless
@@ -24,7 +51,7 @@
 			{
 				var page = await browser.openNewPage(url)
 				await browser.enablePage(page)
-				var pdf = browser.printToPdf(page)
+				var pdf = await browser.printToPdf(page, optionsForPrintToPdf)
 				await browser.closePage(page)
 				return pdf
 			}
@@ -39,7 +66,8 @@
 
 				var url = handler.getNextRequest()
 				var pdf = await html2pdf(url)
-				handler.publishResults(pdf)
+				var name = (new URL(url)).hostname
+				handler.publishResults(name, pdf)
 				setTimeout(mainloop, 3 /* seconds */ * 1000)
 			}
 			mainloop()