golang用西里尔文创建pdf

Question

I need to create pdf file in go with cyrillic symbols. I've started with https://github.com/jung-kurt/gofpdf but it needs 1251 symbols to produce correct cyrillic. I've tried

package main

import (
    "github.com/jung-kurt/gofpdf"
    "fmt"
    "os"
)

func main() {
    pwd, err := os.Getwd()
    if err != nil {
        fmt.Println(err)
        os.Exit(1)
    }
    pdf := gofpdf.New("P", "mm", "A4", "")
    pdf.AddFont("Helvetica", "", pwd + "/font/helvetica_1251.json")
    pdf.AddPage()
    pdf.SetFont("Helvetica", "", 16)
    tr := pdf.UnicodeTranslatorFromDescriptor("cp1251")
    pdf.Cell(15, 50, tr("русский текст"))
    pdf.OutputFileAndClose("test.pdf")
}

but it produce only dots instead of text.

Then I've tried to use https://github.com/golang/freetype to create image with text and then insert it to pdf. So I've tried

package main

import (
    "github.com/jung-kurt/gofpdf"
    "github.com/golang/freetype"
    "image"
    "fmt"
    "os"
    "bytes"
    "image/jpeg"
    "io/ioutil"
    "image/draw"
)

func main() {
    pwd, err := os.Getwd()
    if err != nil {
        fmt.Println(err)
        os.Exit(1)
    }
    dataFont, err := ioutil.ReadFile(pwd + "/font/luxisr.ttf")
    if err != nil {
        fmt.Printf("%v",err)
    }
    f, err := freetype.ParseFont(dataFont)
    if err != nil {
        fmt.Printf("%v",err)
    }
    dst := image.NewRGBA(image.Rect(0, 0, 800, 600))
    draw.Draw(dst, dst.Bounds(), image.White, image.ZP, draw.Src)
    c := freetype.NewContext()
    c.SetDst(dst)
    c.SetClip(dst.Bounds())
    c.SetSrc(image.Black)
    c.SetFont(f)
    c.DrawString("русский текст", freetype.Pt(0, 16))
    pdf := gofpdf.New("P", "mm", "A4", "")
    pdf.AddPage()
    buf := new(bytes.Buffer)
    err = jpeg.Encode(buf, dst, nil)

    if err != nil {
        fmt.Printf("%v",err)
    }

    reader := bytes.NewReader(buf.Bytes())
    textName := "text1"
    pdf.RegisterImageReader(textName, "jpg", reader)
    pdf.Image(textName, 15, 15, 0, 0, false, "jpg", 0, "")
    pdf.OutputFileAndClose("test.pdf")
}

but as a result I receive squares instead of text because it seems that freetype needs unicode symbols for text.

Is it possible to convert strings which are generally in utf-8 to unicode? How can I create pdf or image with cyrillic text?

Thank you.

Answer 1

First, you are ignoring an error in the final line. pdf.OutputFileAndClose returns an error, so you should check it:

err := pdf.OutputFileAndClose("test.pdf")
if err != nil {
    log.Fatal(err)
}

Other than that, your first example works for me. The generated output looks like this:

Here is the code I used, you'll see it's very similar to yours:

package main

import (
    "log"

    "github.com/jung-kurt/gofpdf"
)

func main() {
    pdf := gofpdf.New("P", "mm", "A4", "")
    pdf.AddFont("Helvetica", "", "helvetica_1251.json")
    pdf.AddPage()
    pdf.SetFont("Helvetica", "", 16)
    tr := pdf.UnicodeTranslatorFromDescriptor("cp1251")
    pdf.Cell(15, 50, tr("русский текст"))
    err := pdf.OutputFileAndClose("test.pdf")
    if err != nil {
        log.Println(err)
    }
}

With the above code, the important thing is to make sure helvetica_1251.z, helvetica_1251.json and cp1251.map (from $GOPATH/src/github.com/jung-kurt/gofpdf/font, or generated by the makefont tool) are all in the current directory. If you can confirm that this works for you, you can proceed to move them into the fonts directory and changing the code accordingly. My best guess is that you may be silently ignoring an error warning you about one of these files.

PS I'm running Mac OS X. If you are on another system, make sure you have a version of Helvetica with cyrillic character support installed.

Update

For others facing this problem in the future, I wanted to add the final solution here. From the comments below:

Thanks to jung-kurt I found solution. You can avoid this bug on Windows by adding pdf.SetCompression(true) – Timur Shahmuratov