CDATA sections are used to escape blocks of text containing characters that
would otherwise be regarded as markup. The only delimiter that is
recognized in a CDATA section is the "]]>" string that ends the CDATA
section. CDATA sections cannot be nested. Their primary purpose is for
including material such as XML fragments, without needing to escape all
DOMStringattribute of the
Textnode holds the text that is contained by the CDATA section. Note that this may contain characters that need to be escaped outside of CDATA sections and that, depending on the character encoding ("charset") chosen for serialization, it may be impossible to write out some characters as part of a CDATA section.
CDATASectioninterface inherits from the
CharacterDatainterface through the
CDATASectionnodes are not merged by use of the
normalizemethod of the
Nodeinterface. Because no markup is recognized within a
CDATASection, character numeric references cannot be used as an escape mechanism when serializing. Therefore, action needs to be taken when serializing a
CDATASectionwith a character encoding where some of the contained characters cannot be represented. Failure to do so would not produce well-formed XML.One potential solution in the serialization process is to end the CDATA section before the character, output the character using a character reference or entity reference, and open a new CDATA section for any further characters in the text node. Note, however, that some code conversion libraries at the time of writing do not return an error or exception when a character is missing from the encoding, making the task of ensuring that data is not corrupted on serialization more difficult.
See also the Document Object Model (DOM) Level 2 Core Specification.