fluid-pdf

Easy PDF generation with HTML & CSS using Chromium or Google Chrome

Installation

build.gradle.kts:

dependencies {
	implementation("io.fluidsonic.pdf:fluid-pdf:0.30.0")
}

Usage

HTML file to PDF file

import io.fluidsonic.pdf.*
import java.nio.file.*


suspend fun main() {
	// TODO Change the binary file path to your local Chromium or Google Chrome installation.

	val sourceFile = Path.of("input.html").toAbsolutePath()
	val destinationFile = Path.of("output.pdf").toAbsolutePath()

	coroutineScope {
		val service = PdfGeneratorService.chromiumLauncher(
			path = Path.of("/Applications/Google Chrome.app/Contents/MacOS/Google Chrome")
		)
		service.startIn(this)

		try {
			service.generate(PdfGenerationSource.HtmlFile(sourceFile))
				.writeTo(destinationFile)
		}
		finally {
			service.stop()
		}
	}

	println("PDF has been generated at $destinationFile")
}

• Use PdfGeneratorService.chromiumLauncher() to launch a browser instance.
• Use PdfGeneratorService.devTools() to connect to an existing or a remote browser instance.
• Use service.startIn(CoroutineScope) and service.stop() to manage the service lifecycle.
• Use PdfGeneratorService.generate() to create any number of PDFs.
• Use PdfGenerator interface to hide service details, e.g. in dependency injection.

HTML string to PDF file

service.generate(PdfGenerationSource.Html("<strong>Hello world!</strong>"))
	.writeTo(PdfGenerationDestination.File(destinationFile))

💡 Relative paths in HTML & CSS won't resolve. Using <base href="…"> to specify the base path should help.

Paths in HTML & CSS only work with a Chromium instance on the same machine.

HTML stream to PDF file

val sourceStream: InputStream = …

generator.generate(PdfGenerationSource.HtmlStream(sourceStream))
	.writeTo(PdfGenerationDestination.File(destinationFile))

💡 Relative paths in HTML & CSS won't resolve. Using <base href="…"> to specify the base path should help.

Paths in HTML & CSS only work with a Chromium instance on the same machine.

PDF generation settings

service.generate(
	source = PdfGenerationSource.Html("<strong>Hello world!</strong>"),
	settings = PdfGenerationSettings.default.copy(
		encryption = PdfEncryption(
			ownerPassword = "secret",
			permissions = PdfPermissions.none.copy(
				contentExtractionAllowed = true,
				contentExtractionForAccessibilityAllowed = true,
				printQuality = PdfPermissions.PrintQuality.high,
			),
		),
		includeBackgrounds = false,
		metadata = PdfMetadata(
			title = "My PDF"
		),
		pageMargins = PdfMargins.cm(top = 2.0, right = 2.0, bottom = 1.0, left = 2.0),
		pageOrientation = PdfOrientation.landscape,
		pageSize = PdfSize.A5,
		preferCssPageSize = false
	)
)
	.writeTo(destinationFile)

Output to stream

service.generate(PdfGenerationSource.Html("<strong>Hello world!</strong>"))
	.writeTo(outputStream)

💡 Closing the output stream is the responsibility of the caller. It will not be closed automatically.

TO-DO

Contributions welcome 🙏

• Add unit tests.
• Add KDoc to all public API.
• Write Chromium launcher & DevTools WebSocket client with Kotlin & Ktor, then remove dependency on com.github.kklisura.cdt.
• Test if .generate() works well with significant parallelism.

License

Apache 2.0