Technique H75:Ensuring that Web pages are well-formed
About this Technique
This technique relates to 4.1.1: Parsing (Obsolete and removed) (Sufficient when used for ensuring that Web pages can be parsed).
This technique applies to any XML-based markup languages.
Description
The objective of this technique is to avoid key errors that are known to cause problems for assistive technologies when they are trying to parse contents. Well-formedness is checked by parsing the document with a conforming XML parser and checking if the validation report mentions well-formedness errors. Every conforming XML parser is required to check well-formedness and stop normal processing when a well-formedness error is found (a conforming XML parser does not need to support validation).
Examples
Example 1
XML files include a document type declaration, a xsi:schemaLocation attribute or other type of reference to a schema. The developer can use off-line or online validators, an XML editor or an IDE with XML support (see Resources below) to check well-formedness.
Example 2
When XML files do not include a document type declaration, a xsi:schemaLocation attribute or a processing instruction referencing a schema even though there is a schema for them, the relevant schema is specified by a command line instruction, a user dialog or a configuration file, and the XML files are checked against the schema.
Example 3
When XML files do not include a document type declaration, a xsi:schemaLocation attribute or a processing instruction referencing a schema even though there is a schema for them, the namespace is dereferenced to retrieve a schema document or resource directory (Resource Directory Description Language: RDDL), and the XML files are checked against the schema.
Example 4
When a Website generates XML dynamically instead of serving only static documents, a developer can use XMLUnit, XML Test Suite or a similar framework to test the generated XML code.
Related Resources
No endorsement implied.
- Well-Formed XML Documents in Extensible Markup Language (XML) 1.0 (Third Edition), W3C Recommendation 04 February 2004.
- Well-Formed XML Documents in Extensible Markup Language (XML) 1.1, W3C Recommendation 04 February 2004.
- 4.3.2 Well-Formed Parsed Entities in Extensible Markup Language (XML) 1.1, W3C Recommendation 04 February 2004.
For other resources, see Validating Web pages.
Tests
Procedure
- Load each file into a validating XML parser.
- Check that there are no well-formedness errors.
Expected Results
Step 2 is true.