Lua Requires Chilkat v9.5.0.97+

Add File Attachments to a PDF

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Demonstrates how to attach files to a PDF. This is also known as embedding a file within a PDF. Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local pdf = chilkat.Pdf.new()

-- We'll be adding attachments to this PDF file..
-- Note: We are loading the PDF file into memory.  The PDF file is not kept open at this point.
local success = pdf:load_file("qa_data/pdf/helloWorld.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

-- Build JSON to provide information about the files to be embedded in the PDF.
local json = chilkat.JsonObject.new()
json.emit_compact = false

local i = 0

-- We can attach multiple files in one operation.

-- Here we specify the local relative file path of the 1st file to be embedded.
json.i = i
json:update_string("files[i].description", "Hello World")
json:update_string("files[i].localFilePath", "qa_data/xml/helloWorld.xml")
i = i + 1

-- Specify the 2nd file to be attached.
json.i = i
json:update_string("files[i].description", "Image of starfish")
json:update_string("files[i].localFilePath", "qa_data/jpg/starfish.jpg")
-- You can explicitly specify the subType (i.e. MIME type) of the file.
-- Otherwise Chilkat will use the default MIME type based on the filename extension.
-- If no default MIME type exists, then "application/octet-stream" is used.
json:update_string("files[i].subType", "image/jpeg")
i = i + 1

-- You can alternatively provide the file data from base64 encoded data rather than from a local file.
json.i = i
json:update_string("files[i].description", "Hello World from Data")
json:update_string("files[i].fileData", "SGVsbG8gV29ybGQsIEhlbGxvIFdvcmxkLCBIZWxsbyBXb3JsZCwgSGVsbG8gV29ybGQsIEhlbGxvIFdvcmxk")
json:update_string("files[i].embeddedFilename", "abc.txt")
i = i + 1

-- By default, the filename used within the PDF is the filename part of the local file path.
-- You can change it by specifying the embeddedFilename.
json.i = i
json:update_string("files[i].description", "Invoice")
json:update_string("files[i].localFilePath", "qa_data/xml/invoice.xml")
json:update_string("files[i].embeddedFilename", "invoice_1234.xml")
json:update_string("files[i].subType", "application/xml")

-- The above JSON provides instructions for attaching 4 files to the PDF.
-- Let's attach the files..
-- It is perfectly acceptable to write over the PDF file that was loaded,
-- but in this example we'll write the PDF with attachments to a new PDF file.
success = pdf:add_embedded_files(json, "qa_output/helloWorld_withAttachments.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

-- You can alternatively write the PDF file with attachments to a Chilkat BinData object..
local bd = chilkat.BinData.new()
success = pdf:add_embedded_files_bd(json, bd)
if not success then
    print(pdf.last_error_text)
    return
end

-- Then you can do what you want with the BinData, which contains the binary image of the PDF with attachments.

print("Success.")