Lua Requires Chilkat v11.7.0+

PDF Footnotes in Markdown: Inline, at the End, or Dropped

See more PDF Text Extraction Examples

Demonstrates the "footnotes" option of the "markdown" operation. Small-print notes at the foot of a page are kept where they are ("inline", the default), gathered at the end of the document ("end"), or left out ("none"). Lua

local chilkat = require("chilkat")

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

-- The two-page PDF used in this example is available at footnotes.pdf

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

local json = chilkat.JsonObject.new()
local jsonOut = chilkat.JsonObject.new()

-- Page 1 has two superscript references in the text and the two notes in small print at its foot;
-- page 2 has a third.
success = pdf:extract_text("markdown", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("---- footnotes: inline (default) ----")
print(jsonOut:string_of("markdown"))

json:update_string("footnotes", "end")
success = pdf:extract_text("markdown", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("---- footnotes: end ----")
print(jsonOut:string_of("markdown"))

json:update_string("footnotes", "none")
success = pdf:extract_text("markdown", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("---- footnotes: none ----")
print(jsonOut:string_of("markdown"))

-- Sample output:

-- ---- footnotes: inline (default) ----
-- <!-- page 1 -->
--
-- # The Lens on Loan
--
-- The society located a fourth-order lens of the correct period at a museum1 in the next county, and an agreement to loan it for ten years was signed in November.2 The lens will be lit with a low-wattage electric lamp rather than oil, and it will be displayed as a historic light rather than registered as an aid to navigation.
--
-- 1 The county maritime museum, which holds three lenses from decommissioned lights. 2 The loan is renewable and carries no fee; the society insures the lens.
--
-- <!-- page 2 -->
--
-- # Public Access
--
-- The grounds opened to visitors on weekends from July. Nearly three thousand people climbed the tower over the summer,3 with no incidents.
--
-- 3 Counted at the entrance by the volunteers on duty.
--
-- ---- footnotes: end ----
-- <!-- page 1 -->
--
-- # The Lens on Loan
--
-- The society located a fourth-order lens of the correct period at a museum1 in the next county, and an agreement to loan it for ten years was signed in November.2 The lens will be lit with a low-wattage electric lamp rather than oil, and it will be displayed as a historic light rather than registered as an aid to navigation.
--
-- <!-- page 2 -->
--
-- # Public Access
--
-- The grounds opened to visitors on weekends from July. Nearly three thousand people climbed the tower over the summer,3 with no incidents.
--
-- 1 The county maritime museum, which holds three lenses from decommissioned lights. 2 The loan is renewable and carries no fee; the society insures the lens.
--
-- 3 Counted at the entrance by the volunteers on duty.
--
-- ---- footnotes: none ----
-- <!-- page 1 -->
--
-- # The Lens on Loan
--
-- The society located a fourth-order lens of the correct period at a museum1 in the next county, and an agreement to loan it for ten years was signed in November.2 The lens will be lit with a low-wattage electric lamp rather than oil, and it will be displayed as a historic light rather than registered as an aid to navigation.
--
-- <!-- page 2 -->
--
-- # Public Access
--
-- The grounds opened to visitors on weekends from July. Nearly three thousand people climbed the tower over the summer,3 with no incidents.