Class: Tabula::Extractors::Spreadsheet

Inherits:
ExtractionAlgorithm show all
Defined in:
lib/tabula/extractors/spreadsheet_extraction_algorithm.rb

Overview

Lattice-mode extraction algorithm. Extracts tables by analyzing ruling lines (cell borders) in the PDF.

Constant Summary collapse

MIN_CELLS =

Minimum cells required for a valid table

4
TABULAR_RATIO_THRESHOLD =

Magic heuristic for determining tabular content

0.65

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from ExtractionAlgorithm

extract, #initialize, #name

Constructor Details

This class inherits a constructor from Tabula::Extractors::ExtractionAlgorithm

Class Method Details

.tabular?(page) ⇒ Boolean

Check if a page contains tabular content

Parameters:

  • page (Page) —

    page to check

Returns:

  • (Boolean) 


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# File 'lib/tabula/extractors/spreadsheet_extraction_algorithm.rb', line 42

def self.tabular?(page)
  extractor = new
  tables = extractor.extract(page)
  return false if tables.empty?

  # Check if tables have reasonable structure
  tables.any? do |table|
    ratio = table.row_count.to_f / table.col_count
    ratio.between?(TABULAR_RATIO_THRESHOLD, 1.0 / TABULAR_RATIO_THRESHOLD)
  end
end

Instance Method Details

#extract(page) ⇒ Array<Table>

Extract tables from a page

Parameters:

  • page (Page) —

    page to extract from

Returns:



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# File 'lib/tabula/extractors/spreadsheet_extraction_algorithm.rb', line 17

def extract(page)
  horizontal = page.horizontal_rulings
  vertical = page.vertical_rulings

  return [] if horizontal.empty? || vertical.empty?

  # Find cells from ruling intersections
  cells = find_cells(horizontal, vertical)
  return [] if cells.size < MIN_CELLS

  # Find spreadsheet regions from cells and get cells per region
  cell_groups = find_spreadsheet_areas_with_cells(cells)
  return [] if cell_groups.empty?

  # Extract tables from each region using the found cells
  tables = cell_groups.map do |region_cells|
    extract_table_from_cells(page, region_cells, horizontal, vertical)
  end

  tables.reject(&:empty?)
end