Universal JavaScript Framework


Paragraph Handling

The aim of the component is to facade all the browser differences concerning the behaviour when the user hits the Enter, the Shift+Enter or the Control+Enter combination. And this is by far not an easy task since the differences between the browsers are enormous.

Formatting across multiple paragraphs

Every formatting infos like underline, bold, text color, text size etc. are transferred to the new paragraph. It is likely that the user expects to write on with the same configuration/modifications he applied to the former paragraph.


A paragraph in always aligned completely - the way a word processor also work. This can be irritating at the first time of use if e.g. a paragraph contains multiple lines of text each separated by normal line-breaks, but concerning alignment the paragraph is treated only as whole. So every line of the paragraph (=the whole paragraph) is aligned and not only the line the cursor is currently located.


The HtmlArea offers you two properties to customize the paragraph handling globally and thus customize the behaviour of the component.


The default value of this property is true. It controls whether a new paragraph or a normal line-break is inserted when hitting the Enter key. Since the default behaviour of all word processors is to insert a new paragraph it is recommended to leave this property value with its default.


As every word processor the HtmlArea also supports inserting a normal line-break by using the key combination Shift+Enter


This property also has a default value of true. Since some users are familiar with the key combination Control+Enter to insert a normal line-break the HtmlArea component does support this. So in the default setup Control+Enter and Shift+Enter will end up with the same result.

Technical Background

Paragraph-Handling in Firefox

Browser control

Currently the HtmlArea does only take control and manage the paragraphs on its own if

  • SHIFT and CTRL keys are not pressed
  • caret is not within a word
  • focus node is not an element (current line is not empty)
  • the focus is inside a list

HtmlArea control

If the HtmlArea with its paragraph handling takes control, the following actions are taken.

Phase 1: Collecting styles
  • computed styles of the focus node are collected
  • these styles are grouped in the correct order (e.g. special handling for text-decoration because the text-decoration is linked to the elements color value)
Phase 2: Style string creation
  • a style attribute based on the computed styles is generated for the paragraph element -> only margin, padding and text-align can be applied at paragraph-level. All other styles need to be applied at span elements (=child elements)
  • a string with nested span / font element string is created. This element string is applied to the paragraph element. The nested structure is necessary because some styles need to be applied in the right order
Phase 3: Nodes creation

The following string is applied with the "insertHtml" command

  • an empty span element with an ID
  • a p element with the paragraph style
  • the nested span / font string to reflect the formatting which can't be applied at paragraph level
Phase 4: Cleanup
  • Gecko inserts a p element on his own even if we intercept. This element gets removed afterwards by selecting this paragragph and inserting an empty DIV element at the selection
  • the ID of the empty span is removed (Gecko will remove an empty span then automatically)
  • if an empty paragraph is detected it will be removed to avoid rendering problems

Reasons for own paragraph handling

  • support to keep formatting across multiple paragraphs or lists
  • keep the caret always inside a p element
  • keep control of the kind of line-breaking which is inserted
  • normalize line-breaking
  • act like MS Word


  • DOM manipulations can break Undo/Redo since Gecko is expecting a DOM node which does not exist anymore
  • edge cases can occur which are not targeted yet
  • future browser implementation can change and mess up the current implementation
  • MS Word behaviour can not be achieved in a browser, yet