Lua Requires Chilkat v11.7.0+

Extract a PDF Table with Merged Cells

See more PDF Text Extraction Examples

Demonstrates how merged cells are reported by the "tables" operation: a header cell that spans several columns has colSpan greater than 1, and a row label that spans several rows has rowSpan greater than 1. Also shows the minRows and minColumns options. 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 spans_table.pdf

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

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

-- Grids smaller than minRows x minColumns are not reported as tables.  The defaults are 2 and 2.
-- Setting them higher skips small boxes that are not really tables.
json:update_int("minRows", 3)
json:update_int("minColumns", 3)

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

print("Tables found: " .. jsonOut:int_of("count"))
print(jsonOut:int_of("tables[0].rows") .. " rows x " .. jsonOut:int_of("tables[0].columns") .. " columns")

-- A merged cell is reported once, at its top-left position, with its spans.
-- The positions it covers have no cell of their own.
local rowSpan = 0
local colSpan = 0
local j = 0
local count_j = jsonOut:size_of_array("tables[0].cells")
while j < count_j do
    jsonOut.j = j
    rowSpan = jsonOut:int_of("tables[0].cells[j].rowSpan")
    colSpan = jsonOut:int_of("tables[0].cells[j].colSpan")
    if (rowSpan > 1) or (colSpan > 1) then
        print("row " .. jsonOut:int_of("tables[0].cells[j].row") .. ", col " .. jsonOut:int_of("tables[0].cells[j].col") .. ": \"" .. jsonOut:string_of("tables[0].cells[j].text") .. "\" spans " .. rowSpan .. " row(s) and " .. colSpan .. " column(s)")
    end

    j = j + 1
end

-- Sample output:

-- Tables found: 1
-- 6 rows x 6 columns
-- row 0, col 0: "Area" spans 2 row(s) and 1 column(s)
-- row 0, col 1: "City" spans 2 row(s) and 1 column(s)
-- row 0, col 2: "First Half" spans 1 row(s) and 2 column(s)
-- row 0, col 4: "Second Half" spans 1 row(s) and 2 column(s)
-- row 2, col 0: "East" spans 2 row(s) and 1 column(s)
-- row 4, col 0: "West" spans 2 row(s) and 1 column(s)