Multi Highlighter

TSynMultiSyn (unit SynEdit.Highlighter.Multi) combines several highlighters in the same document, for example HTML with embedded CSS and JavaScript, or Pascal with SQL inside the strings.

How it works

The component has a default highlighter for the text outside the schemes, and a collection of schemes. A scheme is a region of the text, that starts with a given expression, ends with another one and is highlighted with its own highlighter.

Property of TSynMultiSyn	Description
Schemes	The collection of the schemes.
DefaultHighlighter	The highlighter of the text outside the schemes.
DefaultLanguageName	The language name of the whole combination.
OnCustomRange	Event to extend the ranges computed by the highlighters.

Property of a scheme (TScheme)	Description
StartExpr	Regular expression that starts the scheme.
EndExpr	Regular expression that ends the scheme.
Highlighter	The highlighter used inside the scheme.
CaseSensitive	Case sensitive matching of the expressions.
MarkerAttri	The attributes of the start and end markers.
SchemeName	The name of the scheme.
OnCheckStartMarker, OnCheckEndMarker	Events to decide in code whether a marker is valid.

Example

HTML pages with scripts:

1. Drop a TSynMultiSyn, a TSynHTMLSyn and a TSynJScriptSyn.
2. Set DefaultHighlighter to the HTML highlighter.
3. Add a scheme with StartExpr = <script[^>]*>, EndExpr = </script> and Highlighter = the JavaScript highlighter.
4. Assign the TSynMultiSyn to the Highlighter property of the editor.

The same technique allows the links of the comments to be recognized, combining a language with TSynURISyn for TSynURIOpener.