Why do you think the World Wide Web Consortium (W3C) would recommend that XML fi

Question

Why do you think the World Wide Web Consortium (W3C) would recommend that XML files be the standard format for text files instead of CSV files?

Explanation / Answer

Extensible Markup Language (XML) is a markup language created to structure, store, and transport data by defining a set of rules for encoding documents in a format that is both human-readable and machine-readable. It is defined in the XML 1.0 Specification[4] produced by the W3C, and several other related specifications,[5] all gratis open standards.[6] The design goals of XML emphasize simplicity, generality, and usability over the Internet.[7] It is a textual data format with strong support via Unicode for the languages of the world. Although the design of XML focuses on documents, it is widely used for the representation of arbitrary data structures, for example in web services. Many application programming interfaces (APIs) have been developed for software developers to use to process XML data, and several schema systems exist to aid in the definition of XML-based languages. As of 2009, hundreds of XML-based languages have been developed,[8] including RSS, Atom, SOAP, and XHTML. XML-based formats have become the default for many office-productivity tools, including Microsoft Office (Office Open XML), OpenOffice.org and LibreOffice (OpenDocument), and Apple's iWork.[9] XML has also been employed as the base language for communication protocols, such as XMPP. Key terminology The material in this section is based on the XML Specification. This is not an exhaustive list of all the constructs that appear in XML; it provides an introduction to the key constructs most often encountered in day-to-day use. (Unicode) character By definition, an XML document is a string of characters. Almost every legal Unicode character may appear in an XML document. Processor and application The processor analyzes the markup and passes structured information to an application. The specification places requirements on what an XML processor must do and not do, but the application is outside its scope. The processor (as the specification calls it) is often referred to colloquially as an XML parser. Markup and content The characters making up an XML document are divided into markup and content, which may be distinguished by the application of simple syntactic rules. Generally, strings that constitute markup either begin with the character , or they begin with the character & and end with a ;. Strings of characters that are not markup are content. However, in a CDATA section, the delimiters are classified as markup, while the text between them is classified as content. In addition, whitespace before and after the outermost element is classified as markup. Tag A markup construct that begins with . Tags come in three flavors: start-tags; for example: end-tags; for example: empty-element tags; for example: Element A logical document component either begins with a start-tag and ends with a matching end-tag or consists only of an empty-element tag. The characters between the start- and end-tags, if any, are the element's content, and may contain markup, including other elements, which are called child elements. An example of an element is Hello, world. (see hello world). Another is . Attribute A markup construct consisting of a name/value pair that exists within a start-tag or empty-element tag. In the example (below) the element img has two attributes, src and alt: Another example would be Connect A to B. where the name of the attribute is "number" and the value is "3". XML Declaration XML documents may begin by declaring some information about themselves, as in the following example: [edit]Characters and escaping XML documents consist entirely of characters from the Unicode repertoire. Except for a small number of specifically excluded control characters, any character defined by Unicode may appear within the content of an XML document. XML includes facilities for identifying the encoding of the Unicode characters that make up the document, and for expressing characters that, for one reason or another, cannot be used directly. [edit]Valid characters Main article: Valid characters in XML Unicode code points in the following ranges are valid in XML 1.0 documents:[10] U+0009, U+000A, U+000D: these are the only C0 controls accepted in XML 1.0; U+0020–U+D7FF, U+E000–U+FFFD: this excludes some (not all) non-characters in the BMP (all surrogates, U+FFFE and U+FFFF are forbidden); U+10000–U+10FFFF: this includes all code points in supplementary planes, including non-characters. XML 1.1[11] extends the set of allowed characters to include all the above, plus the remaining characters in the range U+0001–U+001F. At the same time, however, it restricts the use of C0 and C1 control characters other than U+0009, U+000A, U+000D, and U+0085 by requiring them to be written in escaped form (for example U+0001 must be written as
or its equivalent). In the case of C1 characters, this restriction is a backwards incompatibility; it was introduced to allow common encoding errors to be detected. The code point U+0000 is the only character that is not permitted in any XML 1.0 or 1.1 document. [edit]Encoding detection The Unicode character set can be encoded into bytes for storage or transmission in a variety of different ways, called "encodings". Unicode itself defines encodings that cover the entire repertoire; well-known ones include UTF-8 and UTF-16.[12] There are many other text encodings that predate Unicode, such as ASCII and ISO/IEC 8859; their character repertoires in almost every case are subsets of the Unicode character set. XML allows the use of any of the Unicode-defined encodings, and any other encodings whose characters also appear in Unicode. XML also provides a mechanism whereby an XML processor can reliably, without any prior knowledge, determine which encoding is being used.[13] Encodings other than UTF-8 and UTF-16 will not necessarily be recognized by every XML parser. [edit]Escaping XML provides escape facilities for including characters which are problematic to include directly. For example: The characters "

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.