poppler-go

An easy to use and intuitive PDF library using Go and Poppler

Features

• Implementation of many poppler-glib public C API methods such as

  • Loading Documents (encrypted as well) (from path, os.File, bytes)
  • Getting Document Info such as metadata, page count, attachment count, PDF version, permissions, keywords, subject, title, author, creation date, modification date etc
  • Setting Document Info such as metadata, title, author, subject, keywords, title, author, craetion date, modification date and many more
  • Getting Pages from a Document by their index or label.
    • Getting PageInfo such as page text, size, thumbnail, images, attachments, annotations and so on
    • Searching text, getting text from a certain region, selecting text etc
    • Rendering a Page to Cairo surfaces for printing and viewing.
    • Getting Media on a page such as videos and saving them.
  • Dealing with forms.
  • Getting all the info about fonts, layers, index in a document.
  • Saving the modified Document at a path
  • Rendering to a PostScript File

• Integration with go-cairo

Poppler

Poppler is a library for rendering PDF files and examining, modifying their structure. This repository contains Go Bindings for the stable C api of poppler (glib) to examine and modify the structure of PDF files and render it's pages to Cairo contexts.

Why?

I once thought about making a tui app for viewing PDF's in go and hence went on a search for PDF rendering, manipulation libraries and saw that poppler was one of the many choices available... But it's go bindings cheggaaa/go-poppler and multitude of it's forks although quite suitable for simple tasks was not as complete as it's other language counterparts, So I thought about making a more complete version of it.

Although there are some edges here and there, I plan on making them as smooth as possible.

Requirements

• Go
• poppler library
• cairo library

For Debian/Ubuntu

sudo apt install libpoppler-dev libcairo2-dev

For Fedora

sudo dnf install poppler-glib-devel cairo-devel

For Arch

sudo pacman -S poppler poppler-data poppler-glib cairo

Official source: poppler, cairo

Examples of common tasks

Run the following command to add the library to your go.mod and look at the examples below

go get github.com/wassup05/poppler-go

• Dealing with PDF metadata

package demo

import (
    "fmt"
    "github.com/wassup05/poppler-go"
)

func main(){
    path := "/path/to/pdf"
    
    doc, err := poppler.NewDocFromFilename(path)
    defer doc.Close()

    if err != nil {
        fmt.Printf("Error opening PDF: %s\n",err.Message)
    }

    fmt.Printf("page count:%d\n",doc.GetPageCount())
    fmt.Printf("author:%s\n",doc.GetAuthor())
    fmt.Printf("creator:%s\n",doc.GetCreator())
    fmt.Printf("keywords:%s\n",doc.GetKeywords())

    doc.SetTitle("blahblah")

    fmt.Printf("title:%s\n",doc.GetTitle()) // blahblah

    info := doc.GetInfo()

    fmt.Printf("info:%#v\n",info) // a convinience method to get all the useful info in one go as a struct
}

• Getting the pages of a document and it's info

package demo

import (
    "fmt"
    "github.com/wassup05/poppler-go"
)

func main(){
    path := "/path/to/pdf"
    
    doc, err := poppler.NewDocFromFilename(path)
    defer doc.Close()

    if err != nil {
        fmt.Printf("Error opening PDF: %s\n",err.Message)
    }

    page := doc.GetPage(2)
    defer page.Close()

    label := page.GetLabel() // gets the label of the page
    height, width := page.GetSize() // gets the height, width of the page
    text := page.GetText() // gets all the text on the page

    fmt.Printf("label:%s\nheight,width: %f, %f\ntext: %s\n",label,height,width,text)

    pageInfo := page.GetInfo() // convinience method

    fmt.Printf("Page Info:%#v\n",pageInfo)
}

• Rendering a PDF page to a SVG

package demo

import (
    "github.com/ungerik/go-cairo"
    "github.com/wassup05/poppler-go"
)

func main(){
	doc, err := poppler.NewDocFromFilename("abs/path/to/pdf")
    defer doc.Close()

	if err != nil {
        fmt.Printf("Error opening PDF: %s\n",err.Message)
	}

	page := doc.GetPage(0) // get the first page
    defer page.Close()

	h, w := page.GetSize()

	surface := cairo.NewSVGSurface("test.svg", w, h, cairo.SVG_VERSION_1_2)

	page.RenderToSurface(surface)

	surface.Destroy() // a svg with name `test.svg` with the contents of the 1st page will be created
}

• Dealing with attachments

package demo

import (
    "fmt"
    "github.com/wassup05/poppler-go"
)

func main(){
	doc, err := poppler.NewDocFromFilename("abs/path/to/pdf")
    defer doc.Close()

	if err != nil {
        fmt.Printf("Error opening PDF: %s\n",err.Message)
	}

    attachments := doc.GetAttachments()

    for i, a := range attachments {
        fmt.Printf("name:%s\n",a.GetName())
        fmt.Printf("description:%s\n",a.GetDescription())

        saveErr := a.Save(fmt.Sprintf("demo-%d",i)) // saves the attachment to the path

        if saveErr != nil {
            // handle the error
        }
    }
}

Missing Features that ARE present in poppler

• Advanced Interaction with form fields, annotations and page structures, Which will be implemented soon
• Extensive Documentation

Credits

• go-pdfium - PDF's for testing
• go-poppler - For inspiartion.

Contributing

check this out

License

GNU General Public License, Version 3.0 (GPL v3.0)