Lua Requires Chilkat v11.7.0+

PDF to Markdown Options: Page Breaks, Images, Tables, Emphasis, Heading Levels

See more PDF Text Extraction Examples

Demonstrates the options of the "markdown" operation: pageBreaks (comment, rule or none), images (placeholder or none), tables (ruled or none), emphasis, and maxHeadingLevel. 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 markdown_options.pdf

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

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

-- First with the default options.
success = pdf:extract_text_sb("markdown", json, sbMarkdown, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("---- default options ----")
print(sbMarkdown:get_as_string())

-- Now change the options:

-- pageBreaks: "comment" (the default) separates pages with <!-- page N -->,
-- "rule" separates them with a horizontal rule (---), and "none" runs the pages together.
json:update_string("pageBreaks", "rule")

-- images: "placeholder" (the default) marks where each image sits with ![image](page-1-image-1);
-- "none" leaves images out.
json:update_string("images", "none")

-- tables: "ruled" (the default) converts tables that have drawn cell borders into Markdown tables;
-- "none" returns their cells as plain text.
json:update_string("tables", "none")

-- emphasis: false leaves out the ** and * markers for bold and italic.
json:update_bool("emphasis", false)

-- maxHeadingLevel: inferred headings deeper than this level are folded into this level.
-- The PDF has three heading levels; with maxHeadingLevel 2 the third level becomes ##.
json:update_int("maxHeadingLevel", 2)

sbMarkdown:clear()
success = pdf:extract_text_sb("markdown", json, sbMarkdown, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("---- custom options ----")
print(sbMarkdown:get_as_string())

-- Sample output:

-- ---- default options ----
-- <!-- page 1 -->
--
-- # Community Garden Handbook
--
-- ## Plots
--
-- ### Plot Sizes
--
-- Plots come in two sizes. A **full plot** is twenty feet by ten feet; a **half plot** is ten feet square. New gardeners are *strongly encouraged* to start with a half plot.
--
-- ![image](page-1-image-1)
--
-- ### Plot Fees
--
-- | Plot | Size | Annual Fee |
-- | --- | --- | --- |
-- | Full | 20 x 10 ft | $60 |
-- | Half | 10 x 10 ft | $35 |
--
-- <!-- page 2 -->
--
-- ## Watering
--
-- ### Schedule
--
-- The shared tanks are filled on Monday and Thursday mornings. Please water by hand from the tanks rather than running a hose from the street tap, which is metered.
--
-- ### Dry Spells
--
-- During a declared drought the committee may limit watering to **two days a week**. Notices are posted on the shed door and sent by e-mail.
--
-- ---- custom options ----
-- # Community Garden Handbook
--
-- ## Plots
--
-- ## Plot Sizes
--
-- Plots come in two sizes. A full plot is twenty feet by ten feet; a half plot is ten feet square. New gardeners are strongly encouraged to start with a half plot.
--
-- ## Plot Fees
--
-- Plot Size Annual Fee
--
-- Full 20 x 10 ft $60
--
-- Half 10 x 10 ft $35
--
-- ---
--
-- ## Watering
--
-- ## Schedule
--
-- The shared tanks are filled on Monday and Thursday mornings. Please water by hand from the tanks rather than running a hose from the street tap, which is metered.
--
-- ## Dry Spells
--
-- During a declared drought the committee may limit watering to two days a week. Notices are posted on the shed door and sent by e-mail.