# XML schema editor

XML schemas are an XML language for describing and constraining the content of XML files.

XML schemas are a proposed alternative for the document type definition (DTD) based on XML. They are a formal specification of element names that indicates which elements are allowed in an XML file, and in which combinations. A schema is functionally equivalent to a DTD, but is written in XML; a schema also provides for extended functionality such as data typing, inheritance, and presentation rules.

For more information on XML schema, refer to:

- http://www.w3.org/TR/xmlschema-0/
- http://www.w3.org/TR/xmlschema-1/
- http://www.w3.org/TR/xmlschema-2/

This product provides an XML schema editor for creating, viewing, and validating XML schemas. Using the XML schema editor, you can do the following:

- Create and delete XML schema components such as complex types, simple types, elements, attributes, attribute groups, and groups
- Edit XML schemas
- Import existing XML schemas for structured viewing

The XML schema support in the XML schema editor is based on the

W3C XML Schema Recommendation Specification of 2 May 2001

The XML Schema specification from the W3C Web site is used for validation.

#### XML schema editor views - Graph, Outline, Properties, and Source

There are four main views you can work with in the XML schema editor:

- Graph - the Graph view provides a graphical way to edit your schema
- Outline - the Outline view shows you the main components in your XML schema. You can use this view to add and remove certain components.
- Properties - the Properties view enables you to edit the properties of your XML schema components
- Source - the Source view enables you to edit your source code directly

#### Status of the XML schema

Three status indicators for the schema are available. They are in the bottom right corner:

- Writable or Read Only.
- (Source view only) Smart Insert or Overwrite. To toggle between these modes, press the Insert button on your keyboard.
- Line and column number.

Related tasks
Creating XML schemas
Editing XML schema properties
Validating an XML schema

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