Lua Requires Chilkat v11.7.0+

Extract Tables from a PDF

See more PDF Text Extraction Examples

Demonstrates the "tables" operation, which returns the tables detected on the pages as rows and cells. Each cell has its row and column (counted from 0), its row and column span, and its text. 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 price_list.pdf

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

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

-- The "tables" operation returns the tables found on the selected pages.
-- Tables are recognized by their drawn cell borders.
success = pdf:extract_text("tables", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("Number of tables: " .. jsonOut:int_of("count"))

-- Used to build each row of output.
local sbRow = chilkat.StringBuilder.new()
local currentRow = 0
local row = 0
local j = 0
local count_j = 0

local i = 0
local count_i = jsonOut:size_of_array("tables")
while i < count_i do
    jsonOut.i = i
    print("Table on page " .. jsonOut:int_of("tables[i].page") .. ": " .. jsonOut:int_of("tables[i].rows") .. " rows x " .. jsonOut:int_of("tables[i].columns") .. " columns, detected by " .. jsonOut:string_of("tables[i].detectedBy"))

    -- The cells are listed row by row.  Print each row as its cells separated by " | ".
    currentRow = -1
    sbRow:set_string("")
    j = 0
    count_j = jsonOut:size_of_array("tables[i].cells")
    while j < count_j do
        jsonOut.j = j
        row = jsonOut:int_of("tables[i].cells[j].row")
        if row ~= currentRow then
            if currentRow >= 0 then
                print(sbRow:get_as_string())
            end

            currentRow = row
            sbRow:set_string("  ")
        else
            sbRow:append(" | ")
        end

        sbRow:append(jsonOut:string_of("tables[i].cells[j].text"))
        j = j + 1
    end

    print(sbRow:get_as_string())
    i = i + 1
end

-- The cells of the first table as JSON:
jsonOut.emit_compact = false
print(jsonOut:emit())

-- Sample output:

-- Number of tables: 1
-- Table on page 1: 8 rows x 5 columns, detected by ruled
--   Code | Product | Unit | Price | In Stock
--   HT-101 | Claw hammer, 16 oz | each | $18.00 | 24
--   HT-102 | Adjustable wrench, 10 in | each | $14.50 | 31
--   HT-103 | Screwdriver set, 6 piece | set | $22.00 | 12
--   HT-104 | Tape measure, 25 ft | each | $9.75 | 40
--   HT-105 | Utility knife | each | $6.20 | 58
--   HT-106 | Pliers, needle nose | each | $11.00 | 19
--   HT-107 | Hand saw, 20 in | each | $21.40 | 8
-- {
--   "count": 1,
--   "tables": [
--     {
--       "page": 1,
--       "detectedBy": "ruled",
--       "rows": 8,
--       "columns": 5,
--       "cells": [
--         {
--           "row": 0,
--           "col": 0,
--           "rowSpan": 1,
--           "colSpan": 1,
--           "text": "Code"
--         },
--         {
--           "row": 0,
--           "col": 1,
--           "rowSpan": 1,
--           "colSpan": 1,
--           "text": "Product"
--         },
--         ...
--       ]
--     }
--   ],
--   "quality": {
--     "rating": "good",
--     ...
--   }
-- }