Editing HTML in Dreamweaver > About Roundtrip HTML

About Roundtrip HTML

Roundtrip HTML is a unique feature in Dreamweaver that lets you move your documents back and forth between a text-based HTML editor and Dreamweaver with little or no effect on the content and structure of the document's original HTML source code. Dreamweaver even maintains and renders some HTML that is technically invalid (such as a font tag enclosing multiple p tags) if such code is supported by browsers. However, the HTML source code that Dreamweaver generates as you edit graphically is always technically valid.

The following are key features of Roundtrip HTML:

	By default, Dreamweaver rewrites overlapping tags, closes open tags that aren't allowed to remain open, and removes extra closing tags when you switch back to Dreamweaver from an external HTML editor or when you open an existing HTML document. If you don't want Dreamweaver to rewrite any HTML, choose Edit > Preferences, then select Code Rewriting to turn off all rewriting. See Code Rewriting preferences. If you turn off code rewriting, any HTML that Dreamweaver would have rewritten is displayed as invalid.
	When Highlight Invalid HTML is turned on, Dreamweaver highlights invalid HTML (that it does not support) in yellow. When you select an invalid tag, Dreamweaver displays information in the Property inspector about how to correct the error. Highlight Invalid HTML is turned on by default in the Code view (or Code inspector). To turn it off, choose Highlight Invalid HTML from the Options menu in the Code view (or Code inspector) window. Error highlighting is always on in the Design view.
	Note: Enable/Disable Invalid HTML Highlighting is only available in the Code view (or Code inspector). Design view always displays error highlighting.
	Dreamweaver does not change tags that it does not recognize—including XML tags—because it has no criteria by which to judge them valid or invalid. If an unrecognizable tag overlaps a valid one, Dreamweaver may mark it as erroneous but does not rewrite the code. For example, the custom tag in the following would be marked erroneous: <MyNewTag><b>text</MyNewTag></b>.
	Dreamweaver does not alter ColdFusion Markup Language (CFML) or Microsoft Active Server Pages (ASP) tags, and it displays icons to identify blocks of CFML or ASP code in the Document window whenever possible. See Editing ColdFusion and Active Server files in Dreamweaver.
	Dreamweaver lets you launch a text-based HTML editor to edit the current document. Dreamweaver is integrated with HomeSite (Windows) and BBEdit (Macintosh). See Using external HTML editors.