Text Input Elements
Overview
Text Inputs include: 
Watir::TextField and
Watir::TextArea.
Note that any Input element that does not define a type attribute is
considered to be a TextField.
These are accessed by calling Browser#text_field or Browser#textarea, respectively.
Creating a TextFieldCollection is accomplished with Browser#text_fields, 
and creating a TextareaCollection is accomplished with Browser#textareas,
For all of the different ways of locating a TextField or TextArea element,
take a look at our Locating Elements Guide.
They also inherit methods from standard Web Elements
Common or Special Methods
The first 3 are defined in Watir::UserEditable module
Standard Setter Interface
TextField#set and TextArea#set take a String argument.
Watir clears the field, then sends the provided keys to the element.
Example
browser = Watir::Browser.start 'watir.com/examples/simple_form.html'
text_field = browser.text_field(id: 'first_name')
text_field.set 'Luke'
text_field.value == 'Luke' # => true
text_field.append ' Perry'
text_field.value == 'Luke Perry' # => true
text_field.clear
text_field.value == '' # => true
text_field.append 'Luke'
text_field.value == 'Luke' # => true
text_field.set ' Perry'
text_field.value == ' Perry' # => true
browser.closeWYSIWYG Editors
Most WYSIWYG Editors function by setting non-input elements to editable with
the attribute content-editable. See WYSIWYG Editors page for more information.