api

package
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 Go to latest Published: Aug 6, 2019 License: Apache-2.0 Imports: 14 Imported by: 0

Documentation

Overview

Package api lets you integrate pdfcpu's operations into your Go backend.

There are two api layers supporting all pdfcpu operations:

  1. The file based layer (used by pdfcpu's cli)
  2. The io.ReadSeeker/io.Writer based layer for backend integration.

For any pdfcpu command there are two functions.

The file based function always calls the io.ReadSeeker/io.Writer based function: 

func CommandFile(inFile, outFile string, conf *pdf.Configuration) error
func Command(rs io.ReadSeeker, w io.Writer, conf *pdf.Configuration) error

eg. for optimization: 

func OptimizeFile(inFile, outFile string, conf *pdf.Configuration) error
func Optimize(rs io.ReadSeeker, w io.Writer, conf *pdf.Configuration) error

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

func AddAttachments 

func AddAttachments(rs io.ReadSeeker, w io.Writer, files []string, conf *pdf.Configuration) error

AddAttachments embeds files into a PDF context read from rs and writes the result to w.

func AddAttachmentsFile 

func AddAttachmentsFile(inFile, outFile string, files []string, conf *pdf.Configuration) (err error)

AddAttachmentsFile embeds files into a PDF context read from inFile and writes the result to outFile.

Example 
// Attach 3 files to in.pdf.
AddAttachmentsFile("in.pdf", "", []string{"img.jpg", "attach.pdf", "test.zip"}, nil)

Output:

func AddWatermarks 

func AddWatermarks(rs io.ReadSeeker, w io.Writer, selectedPages []string, wm *pdf.Watermark, conf *pdf.Configuration) error

AddWatermarks adds watermarks to all pages selected in rs and writes the result to w.

func AddWatermarksFile 

func AddWatermarksFile(inFile, outFile string, selectedPages []string, wm *pdf.Watermark, conf *pdf.Configuration) (err error)

AddWatermarksFile adds watermarks to all selected pages of inFile and writes the result to outFile.

Example 
// Add a "Demo" watermark to all pages of in.pdf along the diagonal running from lower left to upper right.
onTop := false
wm, _ := pdfcpu.ParseWatermarkDetails("Demo", onTop)
AddWatermarksFile("in.pdf", "", nil, wm, nil)

// Stamp all odd pages of in.pdf in red "Confidential" in 48 point Courier using a rotation angle of 45 degrees.
onTop = true
wm, _ = pdfcpu.ParseWatermarkDetails("Confidential, f:Courier, c: 1 0 0, r:45, s:1 abs, p:48", onTop)
AddWatermarksFile("in.pdf", "", []string{"odd"}, wm, nil)

// Add image stamps to in.pdf using absolute scaling and a negative rotation of 90 degrees.
onTop = true
wm, _ = pdfcpu.ParseWatermarkDetails("image.png, s:.5 a, r:-90", onTop)
AddWatermarksFile("in.pdf", "", nil, wm, nil)

// Add a PDF stamp to all pages of in.pdf using the 2nd page of stamp.pdf, use absolute scaling of 0.5
// and rotate along the 2nd diagonal running from upper left to lower right corner.
onTop = true
wm, _ = pdfcpu.ParseWatermarkDetails("stamp.pdf:2, s:.5 a, d:2", onTop)
AddWatermarksFile("in.pdf", "", nil, wm, nil)

Output:

func ChangeOwnerPasswordFile 

func ChangeOwnerPasswordFile(inFile, outFile string, pwOld, pwNew string, conf *pdf.Configuration) error

ChangeOwnerPasswordFile reads inFile, changes the user password and writes the result to outFile. A configuration containing the current passwords is required.

Example 
// Changing the owner password for an AES-256 encrypted file.
conf := pdf.NewAESConfiguration("upw", "opw", 256)
ChangeOwnerPasswordFile("in.pdf", "", "opw", "opwNew", conf)

Output:

func ChangeUserPasswordFile 

func ChangeUserPasswordFile(inFile, outFile string, pwOld, pwNew string, conf *pdf.Configuration) error

ChangeUserPasswordFile reads inFile, changes the user password and writes the result to outFile. A configuration containing the current passwords is required.

Example 
// Changing the user password for an AES-256 encrypted file.
conf := pdf.NewAESConfiguration("upw", "opw", 256)
ChangeUserPasswordFile("in.pdf", "", "upw", "upwNew", conf)

Output:

func CreatePDFFile 

func CreatePDFFile(xRefTable *pdf.XRefTable, outFile string, conf *pdf.Configuration) error

CreatePDFFile creates a PDF file for an xRefTable and writes it to outFile.

func DecryptFile 

func DecryptFile(inFile, outFile string, conf *pdf.Configuration) error

DecryptFile decrypts inFile and writes the result to outFile. A configuration containing the current passwords is required.

Example 
// Decrypting an AES-256 encrypted file.
conf := pdf.NewAESConfiguration("upw", "opw", 256)
DecryptFile("in.pdf", "", conf)

Output:

func EncryptFile 

func EncryptFile(inFile, outFile string, conf *pdf.Configuration) error

EncryptFile encrypts inFile and writes the result to outFile. A configuration containing the current passwords is required.

Example 
// Encrypting a file using AES-256.
conf := pdf.NewAESConfiguration("upw", "opw", 256)
EncryptFile("in.pdf", "", conf)

Output:

func ExtractAttachments 

func ExtractAttachments(rs io.ReadSeeker, outDir string, fileNames []string, conf *pdf.Configuration) error

ExtractAttachments extracts embedded files from a PDF context read from rs into outDir.

func ExtractAttachmentsFile 

func ExtractAttachmentsFile(inFile, outDir string, fileNames []string, conf *pdf.Configuration) error

ExtractAttachmentsFile extracts embedded files from a PDF context read from inFile into outDir.

Example 
// Extract 1 attachment from in.pdf into outDir.
ExtractAttachmentsFile("in.pdf", "outDir", []string{"img.jpg"}, nil)

// Extract all attachments from in.pdf into outDir
ExtractAttachmentsFile("in.pdf", "outDir", nil, nil)

Output:

func ExtractContent 

func ExtractContent(rs io.ReadSeeker, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractContent dumps "PDF source" files from rs into outDir for selected pages.

func ExtractContentFile 

func ExtractContentFile(inFile, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractContentFile dumps "PDF source" files from inFile into outDir for selected pages.

Example 
// Extract content for all pages in PDF syntax from in.pdf into outDir.
ExtractContentFile("in.pdf", "outDir", nil, nil)

Output:

func ExtractFonts 

func ExtractFonts(rs io.ReadSeeker, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractFonts dumps embedded fontfiles from rs into outDir for selected pages.

func ExtractFontsFile 

func ExtractFontsFile(inFile, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractFontsFile dumps embedded fontfiles from inFile into outDir for selected pages.

Example 
// Extract embedded fonts for pages 1-3 from in.pdf into outDir.
ExtractFontsFile("in.pdf", outDir, []string{"1-3"}, nil)

Output:

func ExtractImages 

func ExtractImages(rs io.ReadSeeker, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractImages dumps embedded image resources from rs into outDir for selected pages.

func ExtractImagesFile 

func ExtractImagesFile(inFile, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractImagesFile dumps embedded image resources from inFile into outDir for selected pages.

Example 
// Extract embedded images from in.pdf into outDir.
ExtractImagesFile("in.pdf", "outDir", nil, nil)

Output:

func ExtractMetadata 

func ExtractMetadata(rs io.ReadSeeker, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractMetadata dumps all metadata dict entries for rs into outDir.

func ExtractMetadataFile 

func ExtractMetadataFile(inFile, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractMetadataFile dumps all metadata dict entries for inFile into outDir.

Example 
// Extract all metadata from in.pdf into outDir.
ExtractMetadataFile("in.pdf", "outDir", nil, nil)

Output:

func ExtractPages 

func ExtractPages(rs io.ReadSeeker, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractPages generates single page PDF files from rs in outDir for selected pages.

func ExtractPagesFile 

func ExtractPagesFile(inFile, outDir string, selectedPages []string, conf *pdf.Configuration) error

ExtractPagesFile generates single page PDF files from inFile in outDir for selected pages.

Example 
// Extract all even numbered pages from in.pdf into outDir.
ExtractPagesFile("in.pdf", outDir, []string{"even"}, nil)

Output:

func ImportImages 

func ImportImages(rs io.ReadSeeker, w io.Writer, imgs []io.Reader, imp *pdf.Import, conf *pdf.Configuration) error

ImportImages appends PDF pages containing images to rs and writes the result to w. If rs == nil a new PDF file will be written to w.

func ImportImagesFile 

func ImportImagesFile(imgFiles []string, outFile string, imp *pdf.Import, conf *pdf.Configuration) (err error)

ImportImagesFile appends PDF pages containing images to outFile which will be created if necessary.

Example 
// Convert an image into a single page of out.pdf which will be created if necessary.
// The page dimensions will match the image dimensions.
// If out.pdf already exists, append a new page.
// Use the default import configuration.
ImportImagesFile([]string{"image.png"}, "out.pdf", nil, nil)

// Import images by creating an A3 page for each image.
// Images are page centered with 1.0 relative scaling.
// Import an image as a new page of the existing out.pdf.
imp, _ := pdf.ParseImportDetails("f:A3, p:c, s:1.0")
ImportImagesFile([]string{"a1.png", "a2.jpg", "a3.tiff"}, "out.pdf", imp, nil)

Output:

func Info 

func Info(rs io.ReadSeeker, conf *pdf.Configuration) ([]string, error)

Info returns information about rs.

func InfoFile 

func InfoFile(inFile string, conf *pdf.Configuration) ([]string, error)

InfoFile returns information about inFile.

func InsertPages 

func InsertPages(rs io.ReadSeeker, w io.Writer, selectedPages []string, conf *pdf.Configuration) error

InsertPages inserts a blank page at every page selected of rs and writes the result to w.

func InsertPagesFile 

func InsertPagesFile(inFile, outFile string, selectedPages []string, conf *pdf.Configuration) (err error)

InsertPagesFile inserts a blank page at every inFile page selected and writes the result to w.

Example 
// Insert a blank page into in.pdf before page #3.
InsertPagesFile("in.pdf", "", []string{"3"}, nil)

// Insert a blank page into in.pdf before every page.
InsertPagesFile("in.pdf", "", nil, nil)

Output:

func ListAttachments 

func ListAttachments(rs io.ReadSeeker, conf *pdf.Configuration) ([]string, error)

ListAttachments returns a list of embedded file attachments of rs.

func ListAttachmentsFile 

func ListAttachmentsFile(inFile string, conf *pdf.Configuration) ([]string, error)

ListAttachmentsFile returns a list of embedded file attachments of inFile.

Example 
// Output a list of attachments of in.pdf.
list, _ := ListAttachmentsFile("in.pdf", nil)
for _, s := range list {
	fmt.Println(s)
}

Output:

func ListPermissions 

func ListPermissions(rs io.ReadSeeker, conf *pdf.Configuration) ([]string, error)

ListPermissions returns a list of user access permissions.

func ListPermissionsFile 

func ListPermissionsFile(inFile string, conf *pdf.Configuration) ([]string, error)

ListPermissionsFile returns a list of user access permissions for inFile.

Example 
// Output the current permissions of in.pdf.
list, _ := ListPermissionsFile("in.pdf", nil)
for _, s := range list {
	fmt.Println(s)
}

Output:

func Merge 

func Merge(rsc []io.ReadSeeker, w io.Writer, conf *pdf.Configuration) error

Merge merges a sequence of PDF streams and writes the result to w.

func MergeFile 

func MergeFile(inFiles []string, outFile string, conf *pdf.Configuration) error

MergeFile merges a sequence of inFiles and writes the result to outFile. This operation corresponds to file concatenation in the order specified by inFiles. The first entry of inFiles serves as the destination context where all remaining files get merged into.

Example 
// Merge inFiles by concatenation in the order specified and write the result to out.pdf.
inFiles := []string{"in1.pdf", "in2.pdf"}
MergeFile(inFiles, "out.pdf", nil)

Output:

func NUp 

func NUp(rs io.ReadSeeker, w io.Writer, imgFiles, selectedPages []string, nup *pdf.NUp, conf *pdf.Configuration) error

NUp rearranges PDF pages or images into page grids and writes the result to w. Either rs or imgFiles will be used.

func NUpFile 

func NUpFile(inFiles []string, outFile string, selectedPages []string, nup *pdf.NUp, conf *pdf.Configuration) (err error)

NUpFile rearranges PDF pages or images into page grids and writes the result to outFile.

Example 
// 4-Up in.pdf and write result to out.pdf.
nup, _ := pdf.PDFNUpConfig(4, "")
inFiles := []string{"in.pdf"}
NUpFile(inFiles, "out.pdf", nil, nup, nil)

// 9-Up a sequence of images using format Tabloid w/o borders and no margins.
nup, _ = pdf.ImageNUpConfig(9, "f:Tabloid, b:off, m:0")
inFiles = []string{"in1.png", "in2.jpg", "in3.tiff"}
NUpFile(inFiles, "out.pdf", nil, nup, nil)

// TestGridFromPDF
nup, _ = pdf.PDFGridConfig(1, 3, "f:LegalL")
inFiles = []string{"in.pdf"}
NUpFile(inFiles, "out.pdf", nil, nup, nil)

// TestGridFromImages
nup, _ = pdf.ImageGridConfig(4, 2, "d:500 500, m:20, b:off")
inFiles = []string{"in1.png", "in2.jpg", "in3.tiff"}
NUpFile(inFiles, "out.pdf", nil, nup, nil)

Output:

func Optimize 

func Optimize(rs io.ReadSeeker, w io.Writer, conf *pdf.Configuration) error

Optimize reads a PDF stream from rs and writes the optimized PDF stream to w.

func OptimizeContext 

func OptimizeContext(ctx *pdf.Context) error

OptimizeContext optimizes a PDF context.

func OptimizeFile 

func OptimizeFile(inFile, outFile string, conf *pdf.Configuration) (err error)

OptimizeFile reads inFile and writes the optimized PDF to outFile. If outFile is not provided then inFile gets overwritten which leads to the same result as when inFile equals outFile.

Example 
conf := pdfcpu.NewDefaultConfiguration()

// Set passwords for encrypted files.
conf.UserPW = "upw"
conf.OwnerPW = "opw"

// Configure end of line sequence for writing.
conf.Eol = pdfcpu.EolLF

// Create an optimized version of in.pdf and write it to out.pdf.
OptimizeFile("in.pdf", "out.pdf", conf)

// Create an optimized version of inFile.
// If you want to modify the original file, pass an empty string for outFile.
// Use nil for a default configuration.
OptimizeFile("in.pdf", "", nil)

Output:

func PageCount 

func PageCount(inFile string) (int, error)

PageCount returns inFile's page count.

func ParsePageSelection 

func ParsePageSelection(s string) ([]string, error)

ParsePageSelection ensures a correct page selection expression.

func ReadContext 

func ReadContext(rs io.ReadSeeker, conf *pdf.Configuration) (*pdf.Context, error)

ReadContext uses an io.Readseeker to build an internal structure holding its cross reference table aka the Context.

func ReadContextFile 

func ReadContextFile(inFile string) (*pdf.Context, error)

ReadContextFile returns inFile's validated context.

func RemoveAttachments 

func RemoveAttachments(rs io.ReadSeeker, w io.Writer, fileNames []string, conf *pdf.Configuration) error

RemoveAttachments deletes embedded files from a PDF context read from rs and writes the result to w.

func RemoveAttachmentsFile 

func RemoveAttachmentsFile(inFile, outFile string, files []string, conf *pdf.Configuration) (err error)

RemoveAttachmentsFile deletes embedded files from a PDF context read from inFile and writes the result to outFile.

Example 
// Remove 1 attachment from in.pdf.
RemoveAttachmentsFile("in.pdf", "", []string{"img.jpg"}, nil)

// Remove all attachments from in.pdf
RemoveAttachmentsFile("in.pdf", "", nil, nil)

Output:

func RemovePages 

func RemovePages(rs io.ReadSeeker, w io.Writer, selectedPages []string, conf *pdf.Configuration) error

RemovePages removes selected pages from rs and writes the result to w.

func RemovePagesFile 

func RemovePagesFile(inFile, outFile string, selectedPages []string, conf *pdf.Configuration) (err error)

RemovePagesFile removes selected inFile pages and writes the result to outFile..

Example 
// Remove pages 2 and 8 of in.pdf.
RemovePagesFile("in.pdf", "", []string{"2", "8"}, nil)

// Remove first 2 pages of in.pdf.
RemovePagesFile("in.pdf", "", []string{"-2"}, nil)

// Remove all pages >= 10 of in.pdf.
RemovePagesFile("in.pdf", "", []string{"10-"}, nil)

Output:

func Rotate 

func Rotate(rs io.ReadSeeker, w io.Writer, rotation int, selectedPages []string, conf *pdf.Configuration) error

Rotate rotates selected pages of rs clockwise by rotation degrees and writes the result to w.

func RotateFile 

func RotateFile(inFile, outFile string, rotation int, selectedPages []string, conf *pdf.Configuration) (err error)

RotateFile rotates selected pages of inFile clockwise by rotation degrees and writes the result to outFile.

Example 
// Rotate all pages of in.pdf, clockwise by 90 degrees and write the result to out.pdf.
RotateFile("in.pdf", "out.pdf", 90, nil, nil)

// Rotate the first page of in.pdf by 180 degrees.
// If you want to modify the original file, pass an empty string as outFile.
RotateFile("in.pdf", "", 180, []string{"1"}, nil)

Output:

func SetPermissions 

func SetPermissions(rs io.ReadSeeker, w io.Writer, conf *pdf.Configuration) error

SetPermissions sets user access permissions. inFile has to be encrypted. A configuration containing the current passwords is required.

func SetPermissionsFile 

func SetPermissionsFile(inFile, outFile string, conf *pdf.Configuration) (err error)

SetPermissionsFile sets inFile's user access permissions. inFile has to be encrypted. A configuration containing the current passwords is required.

Example 
// Setting all permissions for the AES-256 encrypted in.pdf.
conf := pdf.NewAESConfiguration("upw", "opw", 256)
conf.Permissions = pdfcpu.PermissionsAll
SetPermissionsFile("in.pdf", "", conf)

// Restricting permissions for the AES-256 encrypted in.pdf.
conf = pdf.NewAESConfiguration("upw", "opw", 256)
conf.Permissions = pdfcpu.PermissionsNone
SetPermissionsFile("in.pdf", "", conf)

Output:

func Split 

func Split(rs io.ReadSeeker, outDir, fileName string, span int, conf *pdf.Configuration) error

Split generates a sequence of PDF files in outDir for the PDF stream read from rs obeying given split span. The default span 1 creates a sequence of single page PDFs.

func SplitFile 

func SplitFile(inFile, outDir string, span int, conf *pdf.Configuration) error

SplitFile generates a sequence of PDF files in outDir for inFile obeying given split span. The default span 1 creates a sequence of single page PDFs.

Example 
// Create single page PDFs for in.pdf in outDir using the default configuration.
SplitFile("in.pdf", "outDir", 1, nil)

// Create dual page PDFs for in.pdf in outDir using the default configuration.
SplitFile("in.pdf", "outDir", 2, nil)

Output:

func Trim 

func Trim(rs io.ReadSeeker, w io.Writer, selectedPages []string, conf *pdf.Configuration) error

Trim generates a trimmed version of rs containing all selected pages and writes the result to w.

func TrimFile 

func TrimFile(inFile, outFile string, selectedPages []string, conf *pdf.Configuration) (err error)

TrimFile generates a trimmed version of inFile containing all selected pages and writes the result to outFile.

Example 
// Create a trimmed version of in.pdf containing odd page numbers only.
TrimFile("in.pdf", "outFile", []string{"odd"}, nil)

// Create a trimmed version of in.pdf containing the first two pages only.
// If you want to modify the original file, pass an empty string for outFile.
TrimFile("in.pdf", "", []string{"1-2"}, nil)

Output:

func Validate 

func Validate(rs io.ReadSeeker, conf *pdf.Configuration) error

Validate validates a PDF stream read from rs.

func ValidateContext 

func ValidateContext(ctx *pdf.Context) error

ValidateContext validates a PDF context.

func ValidateFile 

func ValidateFile(inFile string, conf *pdf.Configuration) error

ValidateFile validates inFile.

Example 
// Use the default configuration to validate in.pdf.
ValidateFile("in.pdf", nil)

Output:

func WriteContext 

func WriteContext(ctx *pdf.Context, w io.Writer) error

WriteContext writes a PDF context to w.

Types

type ReadSeekerCloser 

type ReadSeekerCloser interface {
	io.ReadSeeker
	io.Closer
}

ReadSeekerCloser combines io.ReadSeeker and io.Closer

Source Files

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