The main idea behind this project was:
"How small can I make a PDF generator for it to still be useful for 80% of common PDF generation needs?"
The result is a single .go file with less than 1999 lines of code.
- All the basics for generating PDF documents, enough for generating mundane business reports.
- It's easier to learn about the internals of the PDF format with a smaller library.
- The current version of the file is indicated in the header (the timestamp).
go get github.com/balacode/one-file-pdfAll types in are prefixed with PDF for public, and 'pdf' for private types. The only type you really need to use is PDF, while PDFColorNames are left public for reference.
- You can use all built-in PDF fonts: Courier, Helvetica, Symbol, Times, ZapfDingbats, and their variants
- Recognises 144 web colo(u)r names, or any RGB value
- Stream compression can be turned on or off (normal PDF files compress streams to reduce file size, but turning compression off helps in debugging or learning about PDF commands)
- Properties to set metadata: author, creator, keywords, subject and title
- Set the measurement units you want: cm, inches, points, etc.
- Draw lines with different thickness
- Filled or outline rectangles
- Grayscale PNG images
- Filled and outline circles and ellipses < NEW
- Set columns for outputting text (like arbitrary tab stops on the page)
- Built-in grid that can be enabled to assist measurement and positioning
- Unicode (requires font embedding)
- Font embedding
- PDF encryption
- Paths, curves and complex graphics
package main
import "fmt"
import "github.com/balacode/one-file-pdf"
func main() {
fmt.Println(`Generating a "Hello World" PDF...`)
// create a new PDF using 'A4' page size
var pdf = pdf.NewPDF("A4")
// add a page: this must be done before drawing
pdf.AddPage()
// set the measurement units to centimeters
pdf.SetUnits("cm")
// draw a grid to help us align stuff (just a guide, not necessary)
pdf.DrawUnitGrid()
// draw the word 'HELLO' in orange, using 100pt bold Helvetica font
// - text is placed on top of, not below the Y-coordinate
// - you can use method chaining
pdf.SetFont("Helvetica-Bold", 100).
SetXY(5, 5).
SetColor("Orange").
DrawText("HELLO")
// draw the word 'WORLD' in blue-violet, using 100pt Helvetica font
// note that here we use the colo(u)r hex code instead
// of its name, using the CSS/HTML format: #RRGGBB
pdf.SetXY(5, 9).
SetColor("#8A2BE2").
SetFont("Helvetica", 100).
DrawText("WORLD!")
// draw a flower icon using 300pt Zapf-Dingbats font
pdf.SetX(7).SetY(17).
SetColorRGB(255, 0, 0).
SetFont("ZapfDingbats", 300).
DrawText("a")
// save the file:
// if the file exists, it will be overwritten
// if the file is in use, prints an error message
pdf.SaveFile("hello.pdf")
} // main2018-MAR-08
- New methods DrawCircle(), DrawEllipse(), FillCircle(), FillEllipse()
- New demo demonstrating circles and text wrapping: corporate.pdf ("Synergy Ipsum")
- SetColor(): now allows HTML color values like
"#4C9141 MayGreen", ignores the extra chars. - Log an error when the name of a selected font is unknown.
- Log the specified measurement unit's name when its name is not valid.
2018-MAR-09
- Replaced PDFColor type with standard lib's color.RGBA (import "image/color")
- SetColorRGB(): changed parameters from int to uint8
- Changed PDFPageSize and PDFStandardPageSizes to private structures
- SaveFile() now returns
errorinstead of*PDF, to allow caller to check for IO errors - SetColumnWidths() is no longer limited to 100 columns
- Font names and color names can be specified with spaces, underscores or '-' delimiting words
- Removed module-global PDFErrorHandler, created SetErrorLogger() to set the handler for each PDF instance