Text Formatter

The built-in XML text formatter can adjust whitespace between elements and attributes to make code more readable.

The Text Formatting topic talks about text formatters in general and how to register them as a "feature" language service.

The XmlTextFormatter class is the default implementation of an ITextFormatter service for this language.

Registering with a Syntax Language

Any object that implements ITextFormatter can be associated with a syntax language by registering it as an ITextFormatter service on the language.

The XmlSyntaxLanguage class automatically registers a XmlTextFormatter with itself when it is created, so normally text formatters never need to be set on a XML language unless a custom one is made.

This code creates a custom text formatter (defined in a make-believe CustomXmlTextFormatter class) and registers it with the syntax language that is already declared in the language variable:

language.RegisterTextFormatter(new CustomXmlTextFormatter());

Note

The SyntaxLanguageExtensions.RegisterTextFormatter method in the code snippet above is a helper extension method that gets added to ISyntaxLanguage objects when the ActiproSoftware.Text namespace is imported. See the Service Locator Architecture topic for details on registering and retrieving various service object instances, both via extension methods and generically, as there are some additional requirements for using the extension methods.

Disabling the Functionality

Since this feature is installed as a "feature" service on the language and is installed on XmlSyntaxLanguage by default, it can be disabled by uninstalling the service from the language.

Attribute Spacing Mode

The XmlTextFormatter has an AttributeSpacingMode property that can be set to alter the behavior of the formatter when dealing with whitespace around attributes within an element. None of the modes affect the TagWrapLength feature (described below). The XmlAttributeSpacingMode enumeration defines these three mode options:

Mode	Formatter Behavior
`Preserve`	The formatter will not make changes to the whitespace around attributes. This is the default mode.
`NormalizeWhitespace`	The formatter will adjust any whitespace around attributes to be exactly one space.
`SeparateLines`	The formatter will adjust any whitespace such that each attribute is on a separate line.

Element Spacing Mode

The XmlTextFormatter has an ElementSpacingMode property that can be set to alter the behavior of the formatter when dealing with whitespace in element content. The XmlElementSpacingMode enumeration defines these three mode options:

Mode	Formatter Behavior
`Preserve`	The formatter will not make changes to the whitespace in element content. This is the default mode.
`NormalizeEmptyLines`	The formatter will adjust any whitespace around element content so that there is no more than a single empty line between the content and the containing element.
`RemoveEmptyLines`	The formatter will remove extra whitespace around element content. The actual result depends on the type of content, which can be text-only, one or more elements, or mixed content.

Tag Wrap Length

The XmlTextFormatter has a TagWrapLength property that can be set to cause the formatter to wrap an attribute to the next line when the element length on a particular line exceeds the specified length. This feature will operate regardless of the AttributeSpacingMode.

Setting the value to 0 (zero) will disable the feature, which is the default value. When enabling this wrap feature, a common setting is 120.