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Any XML-based markup languages.
This technique relates to:
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 parserand 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).
[end change] Both steps can be combined by validating the XML document and checking if
the validation report mentions these two types of errors. However, if the
XML document uses only the xml:id attribute as an ID attribute,
validation is not necessary: parsing the XML document with a validating
parser that supports the xml:id
specification is sufficient.
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[begin delete] and to check that all id attribute values are unique[end delete].
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.
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.
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.
Resources are for information purposes only, 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.
xml:id Version 1.0 - W3C Recommendation 9 September 2005.
[end delete]For other resources, see G134: Validating Web pages.
(none currently listed)
Load each file into a validating XML parser.
Check that all id attribute values are unique in the file.
Check that there are no well-formedness errors.
Step 2 is true.