Merge pull request #177 from ruby-docx/update-readme-headers-footers

Update README for headers/footers and fix stale examples

Author: satoryu

README.md

@@ -5,13 +5,13 @@
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-A ruby library/gem for interacting with `.docx` files. currently capabilities include reading paragraphs/bookmarks, inserting text at bookmarks, reading tables/rows/columns/cells and saving the document.
+A ruby library/gem for interacting with `.docx` files. currently capabilities include reading paragraphs/bookmarks, inserting text at bookmarks, reading and writing headers/footers, reading tables/rows/columns/cells and saving the document.
 
 ## Usage
 
 ### Prerequisites
 
-- Ruby 2.6 or later
+- Ruby 2.7 or later
 
 ### Install
 
@@ -63,6 +63,26 @@ doc = Docx::Document.open(buffer)
 # Everything about reading is the same as shown above
 ```
 
+### Reading headers and footers
+
+``` ruby
+require 'docx'
+
+doc = Docx::Document.open('example.docx')
+
+# Headers and footers are returned as hashes keyed by their file name
+# (e.g. "header1", "footer1"), with Nokogiri documents as values.
+doc.headers.each do |name, header|
+  puts name
+  puts header.text
+end
+
+doc.footers.each do |name, footer|
+  puts name
+  puts footer.text
+end
+```
+
 ### Rendering html
 ``` ruby
 require 'docx'
@@ -116,7 +136,11 @@ doc = Docx::Document.open('example.docx')
 doc.bookmarks['example_bookmark'].insert_text_after("Hello world.")
 
 # Insert multiple lines of text at our bookmark
-doc.bookmarks['example_bookmark_2'].insert_multiple_lines_after(['Hello', 'World', 'foo'])
+doc.bookmarks['example_bookmark_2'].insert_multiple_lines(['Hello', 'World', 'foo'])
+
+# Bookmarks placed in headers and footers are included too, and edits to them
+# are saved along with the document.
+doc.bookmarks['header_bookmark'].insert_text_after("Hello from the header.")
 
 # Remove paragraphs
 doc.paragraphs.each do |p|