Lua Requires Chilkat v11.7.0+

Put a Letterhead Behind the First Page of a PDF

See more PDF Watermark Examples

Demonstrates the pdfPage type, which places a page of another PDF as the watermark. It is the way to use a letterhead, a cover overlay or a vector logo that was saved as a PDF, and unlike an image it stays sharp at any size because it is drawn, not resampled. "zOrder" set to back puts it behind the existing content, where a letterhead belongs, and "pages" set to first restricts it to page one. Lua

local chilkat = require("chilkat")

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

-- The PDF used in this example is available at two_page_memo.pdf

-- The PDF used in this example is available at letterhead.pdf

local pdf = chilkat.Pdf.new()
local success = pdf:load_file("qa_data/pdf/two_page_memo.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

local json = chilkat.JsonObject.new()
json:update_string("type", "pdfPage")
json:update_string("pdf.path", "qa_data/pdf/letterhead.pdf")

-- The page of the source PDF to use (1 by default).  "match" instead of a number places source
-- page n on target page n, which suits a set of per-page backgrounds.
json:update_int("pdf.page", 1)

-- Behind the memo's own text, on page one, scaled to the page.
json:update_string("zOrder", "back")
json:update_string("pages", "first")
json:update_string("scale.fit", "page")
json:update_string("id", "letterhead")

local jsonOut = chilkat.JsonObject.new()
success = pdf:watermark("add", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("id: " .. jsonOut:string_of("id") .. " pages: " .. jsonOut:string_of("pages"))

success = pdf:write_file("qa_output/memo_letterhead.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

-- Sample output:

-- id: letterhead pages: 1