Add settings for escape_formulas at global, workbook, worksheet, row and cell levels.

1 files changed, 19 insertions, 1 deletions

diff --git a/examples/escape_formula_example.md b/examples/escape_formula_example.md
index fb23ce66..9a8efc21 100644
--- a/examples/escape_formula_example.md
+++ b/examples/escape_formula_example.md
@@ -1,14 +1,30 @@
 ## Description
 
-You could escape formulas
+You may escape formulas using `escape_formulas` on the global, workbook, worksheet, row and/or cell level.
+This is used to prevent [Formula Injection](https://www.owasp.org/index.php/CSV_Injection) vulnerabilities.
+
+The following are possible:
+
+| Scope     | Example                                                                  | Notes                                                                                      |
+|-----------|--------------------------------------------------------------------------|--------------------------------------------------------------------------------------------|
+| Global    | `Axlsx.escape_formulas = true`                                           | Affects worksheets created *after* setting. Does not affect existing worksheets.           |
+| Workbook  | `workbook.escape_formulas = true`                                        | Affects child worksheets added *after* setting. Does not affect existing child worksheets. |
+| Worksheet | `workbook.add_worksheet(name: 'Name', escape_formulas: true)`            |                                                                                            |
+| Worksheet | `worksheet.worksheet = true`                                             | Affects child rows/cells added *after* setting. Does not affect existing child rows/cells. |
+| Row       | `worksheet.add_row(['=FOO()', '=BAR()], escape_formulas: [true, false])` | Can specify as either Boolean (all cells) or Array (one value per cell).                   |
+| Row       | `row.escape_formulas = [true, false]`                                    | Changes the `escape_formulas` value on existing cells. Can use either Boolean or Array.    |
+| Cell      | `cell.escape_formulas = true`                                            |                                                                                            |
 
 ## Code
 
 ```ruby
 require 'axlsx'
 
+Axlsx.escape_formulas = true
+
 p = Axlsx::Package.new
 wb = p.workbook
+wb.escape_formulas #=> true (initial value will be Axlsx.escape_formulas)
 
 wb.add_worksheet(name: 'Escaping Formulas') do |sheet|
   sheet.add_row [1, 2, 3, '=SUM(A2:C2)'], escape_formulas: true
@@ -17,6 +33,8 @@ wb.add_worksheet(name: 'Escaping Formulas') do |sheet|
     '=IF(13+13=4,4,5)',
     '=IF(99+99=4,4,5)'
   ], escape_formulas: [true, false, true]
+
+  sheet.rows.first.cells.first.escape_formulas = false
 end
 
 p.serialize 'escape_formula_example.xlsx'