wkhtmltopdf Go bindings and high level interface for HTML to PDF conversion

Last update: Dec 17, 2022

Comments: 11

wkhtmltopdf Go bindings and high level interface for HTML to PDF conversion.

Implements wkhtmltopdf Go bindings. It can be used to convert HTML documents to PDF files. The package does not use the wkhtmltopdf binary. Instead, it uses the wkhtmltox library directly.

Full documentation can be found at: https://pkg.go.dev/github.com/adrg/go-wkhtmltopdf.

Examples

Prerequisites

In order to use the package, wkhtmltox must be installed. Installation packages for multiple operating systems can be found at https://builds.wkhtmltopdf.org and https://github.com/wkhtmltopdf/packaging/releases.

On Debian based distributions, use dpkg to install the downloaded installation package.

sudo dpkg -i wkhtmltox.deb
sudo ldconfig

Installation

go get github.com/adrg/go-wkhtmltopdf

Usage

package main

import (
	"log"
	"os"

	pdf "github.com/adrg/go-wkhtmltopdf"
)

func main() {
	// Initialize library.
	if err := pdf.Init(); err != nil {
		log.Fatal(err)
	}
	defer pdf.Destroy()

	// Create object from file.
	object, err := pdf.NewObject("sample1.html")
	if err != nil {
		log.Fatal(err)
	}
	object.Header.ContentCenter = "[title]"
	object.Header.DisplaySeparator = true

	// Create object from URL.
	object2, err := pdf.NewObject("https://google.com")
	if err != nil {
		log.Fatal(err)
	}
	object.Footer.ContentLeft = "[date]"
	object.Footer.ContentCenter = "Sample footer information"
	object.Footer.ContentRight = "[page]"
	object.Footer.DisplaySeparator = true

	// Create object from reader.
	inFile, err := os.Open("sample2.html")
	if err != nil {
		log.Fatal(err)
	}
	defer inFile.Close()

	object3, err := pdf.NewObjectFromReader(inFile)
	if err != nil {
		log.Fatal(err)
	}
	object3.Zoom = 1.5
	object3.TOC.Title = "Table of Contents"

	// Create converter.
	converter, err := pdf.NewConverter()
	if err != nil {
		log.Fatal(err)
	}
	defer converter.Destroy()

	// Add created objects to the converter.
	converter.Add(object)
	converter.Add(object2)
	converter.Add(object3)

	// Set converter options.
	converter.Title = "Sample document"
	converter.PaperSize = pdf.A4
	converter.Orientation = pdf.Landscape
	converter.MarginTop = "1cm"
	converter.MarginBottom = "1cm"
	converter.MarginLeft = "10mm"
	converter.MarginRight = "10mm"

	// Convert objects and save the output PDF document.
	outFile, err := os.Create("out.pdf")
	if err != nil {
		log.Fatal(err)
	}
	defer outFile.Close()

	if err := converter.Run(outFile); err != nil {
		log.Fatal(err)
	}
}

Stargazers over time

Contributing

Contributions in the form of pull requests, issues or just general feedback, are always welcome. See CONTRIBUTING.MD.

Contributors: adrg, leandrosilva.

References

For more information see the wkhtmltopdf documentation and the wkhtmltox documentation.

License

This project is licensed under the MIT license. See LICENSE for more details.

Owner

Adrian-George Bostan

https://github.com/adrg/go-wkhtmltopdf https://pkg.go.dev/github.com/adrg/go-wkhtmltopdf

Comments

panic happens

panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x4433cf4]

goroutine 1 [running]: github.com/adrg/go-wkhtmltopdf.(*objectRegistry).add(0x0, 0x7b117c0, 0x44daf40, 0xc0001c3ab0) /Users/machel/gopath/pkg/mod/github.com/adrg/[email protected]/object_registry.go:39 +0x34 github.com/adrg/go-wkhtmltopdf.NewConverterWithOpts(0xc0001ab440, 0xc0001a9e90, 0xc00000ed40, 0x0) /Users/machel/gopath/pkg/mod/github.com/adrg/[email protected]/converter.go:276 +0x1e5 github.com/adrg/go-wkhtmltopdf.NewConverter(...) /Users/machel/gopath/pkg/mod/github.com/adrg/[email protected]/converter.go:235 main.HtmlCvtPdf(0x459dc00, 0xc00002c0a8, 0xc00002cb6c, 0x4, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0)

Two Objects with web url fail the rendering

In the example present in readme.md, I made a small change. Added two urls, thus two objects. This fails with

2021/10/06 12:09:50 could not convert the added objects

package main

import (
	"log"
	"os"

	pdf "github.com/adrg/go-wkhtmltopdf"
)

func main() {
	// Initialize library.
	if err := pdf.Init(); err != nil {
		log.Fatal(err)
	}
	defer pdf.Destroy()

	// Create object from file.
	object, err := pdf.NewObject("https://google.com")
	if err != nil {
		log.Fatal(err)
	}
	object.Header.ContentCenter = "[title]"
	object.Header.DisplaySeparator = true

	// Create object from URL.
	object2, err := pdf.NewObject("https://google.com")
	if err != nil {
		log.Fatal(err)
	}
	object.Footer.ContentLeft = "[date]"
	object.Footer.ContentCenter = "Sample footer information"
	object.Footer.ContentRight = "[page]"
	object.Footer.DisplaySeparator = true


	// Create converter.
	converter, err := pdf.NewConverter()
	if err != nil {
		log.Fatal(err)
	}
	defer converter.Destroy()

	// Add created objects to the converter.
	converter.Add(object)
	converter.Add(object2)

	// Set converter options.
	converter.Title = "Sample document"
	converter.PaperSize = pdf.A4
	converter.Orientation = pdf.Landscape
	converter.MarginTop = "1cm"
	converter.MarginBottom = "1cm"
	converter.MarginLeft = "10mm"
	converter.MarginRight = "10mm"

	// Convert objects and save the output PDF document.
	outFile, err := os.Create("out.pdf")
	if err != nil {
		log.Fatal(err)
	}
	defer outFile.Close()

	if err := converter.Run(outFile); err != nil {
		log.Fatal(err)
	}
}

Prerequisites Install Error
Hello

When I followed this instruction to install wkhtmltox in my Windows, some errors occured.

I chose to install wkhtmltopdf in E:\wkhtmltox.

When I tried to use "go build" in cmd, I got the message as follows. It said "package .: no Go files in E:\wkhtmltox". How can I solve this problem?

Another issue may associate with the first problem.

Although I "go build" failed, I still tried to run my program. Unfortunately, it did not work and gave me some error messages. How can I solve with it?

Please Help me! Thank you!

go-wkhtmltopdf missing wkhtmltox.dll

Hello,

I'm building a program using go-wkhtmltopdf. I followed the install guide and installed the wkhtmltopdf as requested.

When I run my program, I have the following err: the code cannot proceed because wkhtmltox.dll was not found. Reinstallling may ffix the problem

Any Idea on how to tell go-wkhtmltopdf where to find the requested dll? Bellow my go env output:

set GO111MODULE=auto
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\xxx\AppData\Local\go-build
set GOENV=C:\Users\xxx\AppData\Roaming\go\env
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\xx\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\xx\go
set GOPRIVATE=
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=C:\Users\xx\go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=C:\Users\xxx\go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.16
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=C:\Users\xxx\AppData\Local\Temp\go-build397288522=/tmp/go-build -gno-record-gcc-switches

PS: I'm using mingw64

Getting error on get the package

> go get github.com/adrg/go-wkhtmltopdf
go: finding github.com/adrg/go-wkhtmltopdf v0.2.2
go: downloading github.com/adrg/go-wkhtmltopdf v0.2.2
go: extracting github.com/adrg/go-wkhtmltopdf v0.2.2
# github.com/adrg/go-wkhtmltopdf
../../go/pkg/mod/github.com/adrg/[email protected]/converter.go:7:10: fatal error: wkhtmltox/pdf.h: No such file or directory
 #include <wkhtmltox/pdf.h>
          ^~~~~~~~~~~~~~~~~
compilation terminated.

Errors

WARNING: QApplication was not created in the main() thread. QObject::startTimer: QTimer can only be used with threads started with QThread QObject::startTimer: QTimer can only be used with threads started with QThread QObject::startTimer: QTimer can only be used with threads started with QThread QObject::startTimer: QTimer can only be used with threads started with QThread
I did a bunch of cool stuff. Hopefully it helps!

I added those wkhtmltox files for Windows (.dll + .h), an example folder containing the README example (very slightly modified), a Makefile, and a .gitignore file. Also I made a change in the cgo directives to consider -L additionally to -l. And finally, I added a bunch of new thing in the README.

Inconsistent pdf formatting and output

I am using the code below to generate my pdf using the library. The code executes appropriately. However, most of the time I lose my HTML formatting or even data in many cases. What could be the issue? Could this be memory related?

Note: My HTML has some css and js

package dummy

import (
	"code/common"
	"log"
	"os"

	pdf "github.com/adrg/go-wkhtmltopdf"
)

func GeneratePdf(filename string) {
	

	// Initialize library.
	if err := pdf.Init(); err != nil {
		log.Println(err)
	}
	defer pdf.Destroy()
	

	// Create object from file.
	object, err := pdf.NewObject("./inputhtml/uc_" + filename + ".html")
	if err != nil {
		log.Println(err)
	}

	// Create object from URL.
	object2, err := pdf.NewObject("./inputhtml/tc_" + filename + ".html")
	if err != nil {
		log.Println(err)
	}


	// Create object from reader.
	object3, err := pdf.NewObject("./inputhtml/invoice_" + filename + ".html")
	if err != nil {
		log.Println(err)
	}

	object4, err := pdf.NewObject("./inputhtml/feru_" + filename + ".html")
	if err != nil {
		log.Println(err)
	}



	// Create converter.
	converter, err := pdf.NewConverter()
	if err != nil {
		log.Println(err)
	}
	defer converter.Destroy()

	// Add created objects to the converter.
	converter.Add(object)
	converter.Add(object2)
	converter.Add(object3)
	converter.Add(object4)

	// Set converter options.
	converter.Title = "Out documents"
	converter.PaperSize = pdf.A4
	converter.Orientation = pdf.Portrait
	converter.MarginTop = "1cm"
	converter.MarginBottom = "1cm"
	converter.MarginLeft = "10mm"
	converter.MarginRight = "10mm"

	// Convert objects and save the output PDF document.
	outFile, err := os.Create(common.CONST_TMPPDF_FOLDER + "out_" + filename + ".pdf")
	if err != nil {
		log.Println(err)
	}
	defer outFile.Close()

	if err := converter.Run(outFile); err != nil {
		log.Println(err)
	}
}

Panic WARNING: QApplication was not created in the main() thread.

Test demo ,Two requst will be panic

package main

import (
	"log"
	"net/http"
	"os"

	pdf "github.com/adrg/go-wkhtmltopdf"
)

func PrintHandle(w http.ResponseWriter, r *http.Request) {
	if err := pdf.Init(); err != nil {
		log.Fatal(err)
	}
	defer pdf.Destroy()

	// Create object from file.
	object, err := pdf.NewObject("https://www.baidu.com")
	if err != nil {
		log.Fatal(err)
	}

	// Create converter.
	converter, err := pdf.NewConverter()
	if err != nil {
		log.Fatal(err)
	}
	defer converter.Destroy()

	// Add created objects to the converter.
	converter.Add(object)

	// Set converter options.
	converter.Title = "Sample document"
	converter.PaperSize = pdf.A4

	// Convert objects and save the output PDF document.
	outFile, err := os.OpenFile("output.pdf", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0755)
	if err != nil {
		log.Fatal(err)
	}
	defer outFile.Close()

	if err := converter.Run(outFile); err != nil {
		log.Fatal(err)
	}
	w.Write([]byte("ok"))
}

func main() {
	http.HandleFunc("/", PrintHandle)
	http.ListenAndServe("127.0.0.1:10000", nil)
}

Panic Data

WARNING: QApplication was not created in the main() thread.
QObject::startTimer: QTimer can only be used with threads started with QThread
QObject::startTimer: QTimer can only be used with threads started with QThread
QObject::connect: Cannot connect (null)::configurationAdded(QNetworkConfiguration) to QNetworkConfigurationManager::configurationAdded(QNetworkConfiguration)
QObject::connect: Cannot connect (null)::configurationRemoved(QNetworkConfiguration) to QNetworkConfigurationManager::configurationRemoved(QNetworkConfiguration)
QObject::connect: Cannot connect (null)::configurationChanged(QNetworkConfiguration) to QNetworkConfigurationManager::configurationChanged(QNetworkConfiguration)
QObject::connect: Cannot connect (null)::onlineStateChanged(bool) to QNetworkConfigurationManager::onlineStateChanged(bool)
QObject::connect: Cannot connect (null)::configurationUpdateComplete() to QNetworkConfigurationManager::updateCompleted()
fatal error: unexpected signal during runtime execution
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x7f6a131f884e]

runtime stack:
runtime.throw({0x65eb86, 0x7f6a135b7028})
        /usr/local/go/src/runtime/panic.go:1198 +0x71
runtime.sigpanic()
        /usr/local/go/src/runtime/signal_unix.go:719 +0x396

goroutine 6 [syscall]:
runtime.cgocall(0x5f51c0, 0xc00015b8f0)
        /usr/local/go/src/runtime/cgocall.go:156 +0x5c fp=0xc00015b8c8 sp=0xc00015b890 pc=0x4067dc
github.com/adrg/go-wkhtmltopdf._Cfunc_wkhtmltopdf_convert(0x7f69d80154f0)
        _cgo_gotypes.go:137 +0x4c fp=0xc00015b8f0 sp=0xc00015b8c8 pc=0x5ee48c
github.com/adrg/go-wkhtmltopdf.(*Converter).Run.func1(0xc0000b6000)
        /home/aveyuan/go/pkg/mod/github.com/adrg/[email protected]/converter.go:304 +0x46 fp=0xc00015b928 sp=0xc00015b8f0 pc=0x5ef766
github.com/adrg/go-wkhtmltopdf.(*Converter).Run(0xc0000b6000, {0x6a64e0, 0xc0000ba008})
        /home/aveyuan/go/pkg/mod/github.com/adrg/[email protected]/converter.go:304 +0x73 fp=0xc00015b990 sp=0xc00015b928 pc=0x5ef3d3
main.PrintHandle({0x6aaea0, 0xc0000aa000}, 0x0)
        /home/aveyuan/project/go/fkpdf/main.go:44 +0x2d7 fp=0xc00015ba48 sp=0xc00015b990 pc=0x5f4c57
net/http.HandlerFunc.ServeHTTP(0x0, {0x6aaea0, 0xc0000aa000}, 0x0)
        /usr/local/go/src/net/http/server.go:2047 +0x2f fp=0xc00015ba70 sp=0xc00015ba48 pc=0x5dcbcf
net/http.(*ServeMux).ServeHTTP(0x0, {0x6aaea0, 0xc0000aa000}, 0xc000184100)
        /usr/local/go/src/net/http/server.go:2425 +0x149 fp=0xc00015bac0 sp=0xc00015ba70 pc=0x5de4c9
net/http.serverHandler.ServeHTTP({0xc000090030}, {0x6aaea0, 0xc0000aa000}, 0xc000184100)
        /usr/local/go/src/net/http/server.go:2879 +0x43b fp=0xc00015bb80 sp=0xc00015bac0 pc=0x5df7fb
net/http.(*conn).serve(0xc000110960, {0x6abca0, 0xc000100de0})
        /usr/local/go/src/net/http/server.go:1930 +0xb08 fp=0xc00015bfb8 sp=0xc00015bb80 pc=0x5dbf28
net/http.(*Server).Serve·dwrap·87()
        /usr/local/go/src/net/http/server.go:3034 +0x2e fp=0xc00015bfe0 sp=0xc00015bfb8 pc=0x5e014e
runtime.goexit()
        /usr/local/go/src/runtime/asm_amd64.s:1581 +0x1 fp=0xc00015bfe8 sp=0xc00015bfe0 pc=0x465281
created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:3034 +0x4e8

goroutine 1 [IO wait]:
internal/poll.runtime_pollWait(0x7f69e860bf58, 0x72)
        /usr/local/go/src/runtime/netpoll.go:234 +0x89
internal/poll.(*pollDesc).wait(0xc000144000, 0xc00002a000, 0x0)
        /usr/local/go/src/internal/poll/fd_poll_runtime.go:84 +0x32
internal/poll.(*pollDesc).waitRead(...)
        /usr/local/go/src/internal/poll/fd_poll_runtime.go:89
internal/poll.(*FD).Accept(0xc000144000)
        /usr/local/go/src/internal/poll/fd_unix.go:402 +0x22c
net.(*netFD).accept(0xc000144000)
        /usr/local/go/src/net/fd_unix.go:173 +0x35
net.(*TCPListener).accept(0xc00000e0d8)
        /usr/local/go/src/net/tcpsock_posix.go:140 +0x28
net.(*TCPListener).Accept(0xc00000e0d8)
        /usr/local/go/src/net/tcpsock.go:262 +0x3d
net/http.(*Server).Serve(0xc000142000, {0x6aacf0, 0xc00000e0d8})
        /usr/local/go/src/net/http/server.go:3002 +0x394
net/http.(*Server).ListenAndServe(0xc000142000)
        /usr/local/go/src/net/http/server.go:2931 +0x7d
net/http.ListenAndServe(...)
        /usr/local/go/src/net/http/server.go:3185
main.main()
        /home/aveyuan/project/go/fkpdf/main.go:52 +0x65

goroutine 7 [IO wait]:
internal/poll.runtime_pollWait(0x7f69e860bd88, 0x72)
        /usr/local/go/src/runtime/netpoll.go:234 +0x89
internal/poll.(*pollDesc).wait(0xc000144100, 0xc000158000, 0x0)
        /usr/local/go/src/internal/poll/fd_poll_runtime.go:84 +0x32
internal/poll.(*pollDesc).waitRead(...)
        /usr/local/go/src/internal/poll/fd_poll_runtime.go:89
internal/poll.(*FD).Read(0xc000144100, {0xc000158000, 0x1000, 0x1000})
        /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
net.(*netFD).Read(0xc000144100, {0xc000158000, 0x400, 0xc00015f6b0})
        /usr/local/go/src/net/fd_posix.go:56 +0x29
net.(*conn).Read(0xc000010040, {0xc000158000, 0x400, 0xc000100f38})
        /usr/local/go/src/net/net.go:183 +0x45
net/http.(*connReader).Read(0xc000100f30, {0xc000158000, 0x1000, 0x1000})
        /usr/local/go/src/net/http/server.go:780 +0x16d
bufio.(*Reader).fill(0xc00006c300)
        /usr/local/go/src/bufio/bufio.go:101 +0x103
bufio.(*Reader).ReadSlice(0xc00006c300, 0x40)
        /usr/local/go/src/bufio/bufio.go:360 +0x2f
bufio.(*Reader).ReadLine(0xc00006c300)
        /usr/local/go/src/bufio/bufio.go:389 +0x27
net/textproto.(*Reader).readLineSlice(0xc000100f90)
        /usr/local/go/src/net/textproto/reader.go:57 +0x99
net/textproto.(*Reader).ReadLine(...)
        /usr/local/go/src/net/textproto/reader.go:38
net/http.readRequest(0xc000010040)
        /usr/local/go/src/net/http/request.go:1029 +0x79
net/http.(*conn).readRequest(0xc000110a00, {0x6abbf8, 0xc000028280})
        /usr/local/go/src/net/http/server.go:966 +0x225
net/http.(*conn).serve(0xc000110a00, {0x6abca0, 0xc000100de0})
        /usr/local/go/src/net/http/server.go:1856 +0x865
created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:3034 +0x4e8

goroutine 34 [IO wait]:
internal/poll.runtime_pollWait(0x7f69e860be70, 0x72)
        /usr/local/go/src/runtime/netpoll.go:234 +0x89
internal/poll.(*pollDesc).wait(0xc000144080, 0xc000090041, 0x0)
        /usr/local/go/src/internal/poll/fd_poll_runtime.go:84 +0x32
internal/poll.(*pollDesc).waitRead(...)
        /usr/local/go/src/internal/poll/fd_poll_runtime.go:89
internal/poll.(*FD).Read(0xc000144080, {0xc000090041, 0x1, 0x1})
        /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
net.(*netFD).Read(0xc000144080, {0xc000090041, 0x0, 0x0})
        /usr/local/go/src/net/fd_posix.go:56 +0x29
net.(*conn).Read(0xc000010038, {0xc000090041, 0x0, 0x0})
        /usr/local/go/src/net/net.go:183 +0x45
net/http.(*connReader).backgroundRead(0xc000090030)
        /usr/local/go/src/net/http/server.go:672 +0x3f
created by net/http.(*connReader).startBackgroundRead
        /usr/local/go/src/net/http/server.go:668 +0xcf
exit status 2

Blank pdf for react website.

I am trying to save a page from my site built in react. It generate the blank pdf as site is take sometime to load. Is there any way to fix this issue?
Converged my fork to yours master with addition

As per what I said on issue #3 (here), I did refactor my fork to use your new standard ConverterOpts and ObjectOpts on my proposed of a standard HTTP handler for converting (here and here).

Also, I removed everything that was specific to my fork, things that were hardcoded to work on my fork, and whatnot.

If you think it is not worth to merge it now, that's cool. I'm fine with that.

In any case, thanks for sharing your code over here.

Cheers.

wkhtmltopdf Go bindings and high level interface for HTML to PDF conversion

wkhtmltopdf Go bindings and high level interface for HTML to PDF conversion.

Prerequisites

Installation

Usage

Stargazers over time

Contributing

References

License

Owner

Adrian-George Bostan

Comments

panic happens

Two Objects with web url fail the rendering

Prerequisites Install Error

go-wkhtmltopdf missing wkhtmltox.dll

Getting error on get the package

Errors

I did a bunch of cool stuff. Hopefully it helps!

Inconsistent pdf formatting and output

Panic WARNING: QApplication was not created in the main() thread.

Blank pdf for react website.

Converged my fork to yours master with addition

Related tags

Assembly syntax that makes you feel like you're writing code in a high-level language.

HTTP service to generate PDF from Json requests

A vitamin C rich, book, pdf & documentation brewing library for e-readers/e-ink readers

Optimized bit-level Reader and Writer for Go.

User level X Keyboard Grabber

Instant online preview of HTML files or websites.

Lib to extract information of tag html meta

Go bindings for unarr (decompression library for RAR, TAR, ZIP and 7z archives)

Native Go bindings for D-Bus

GObject-introspection based bindings generator

Some plain Go/Golang i2c sensor bindings to Waveshare Sense HAT for raspberry pi

The gofinder program is an acme user interface to search through Go projects.

Simple interface to libmagic for Go Programming Language

Go language interface to the PAPI performance API

A go interface to NotifyMyAndroid

Generate type-safe Go converters by simply defining an interface

Third party extension interface for sillyGirl.

Simple example program using CRUD operations to interface with azcosmos

Data interface for salesforce price bulk get