Soprano  2.7.56
Public Types | Static Public Member Functions
Soprano::LanguageTag Class Reference

A LanguageTag represents a language according to RFC 3066 and RFC 4646. More...

#include <Soprano/LanguageTag>

List of all members.

Public Types

enum  MatchFilter { MatchFilterBasic = 0, MatchFilterExtended = 1 }
enum  LookupFlag { LookupFlagNone = 0, LookupFlagNoFallback = 1 }

Public Member Functions

Constructors
 LanguageTag ()
 LanguageTag (const LanguageTag &other)
 LanguageTag (const char *tag)
 LanguageTag (const QLatin1String &tag)
 LanguageTag (const QString &tag)
 LanguageTag (const QLocale &locale)
 LanguageTag (QLocale::Language lang, QLocale::Country country=QLocale::AnyCountry)
 ~LanguageTag ()
Operators
LanguageTagoperator= (const LanguageTag &other)
bool operator== (const LanguageTag &other) const
bool operator!= (const LanguageTag &other) const
bool operator< (const LanguageTag &other) const
bool operator<= (const LanguageTag &other) const
bool operator> (const LanguageTag &other) const
bool operator>= (const LanguageTag &other) const
bool matches (const LanguageTag &range, MatchFilter scheme=MatchFilterBasic) const
Information
bool isEmpty () const
bool isValid () const
QStringList subTags () const
Conversion
QString toString () const
QString toPrettyString () const
QLocale toLocale () const
 operator QString () const

Static Public Member Functions

static int lookup (const QList< LanguageTag > &choices, const QList< LanguageTag > &priority, LookupFlags flags=LookupFlagNone, MatchFilter scheme=MatchFilterBasic)
static int lookup (const QList< LanguageTag > &choices, const LanguageTag &priority, LookupFlags flags=LookupFlagNone, MatchFilter scheme=MatchFilterBasic)

Detailed Description

A LanguageTag represents a language according to RFC 3066 and RFC 4646.

Author:
Greg Beauchesne greg_.nosp@m.b@vi.nosp@m.sion-.nosp@m.play.nosp@m..com
Since:
2.3

Definition at line 44 of file languagetag.h.


Member Enumeration Documentation

Enumerator:
MatchFilterBasic 

Represents basic language filtering as described in RFC 3066 section 2.5 (or RFC 4647 section 3.3.1). Basic language filtering checks only that the range string is a prefix of a language tag and that the prefix is followed by "-" or the end of the string. Additionally, the language range "*" matches all tags.

MatchFilterExtended 

Represents extended language filtering as described in RFC 4647 section 3.3.2. Extended language filtering breaks tags up into subtags and is permitted to skip subtags in the language tag in order to match parts of the range string.

Definition at line 47 of file languagetag.h.

Flags for performing LanguageTag lookups.

See also:
lookup()
Enumerator:
LookupFlagNone 
LookupFlagNoFallback 

Disables fallback behavior for lookup ranges.

Definition at line 70 of file languagetag.h.


Constructor & Destructor Documentation

Default constructor. Creates an empty language tag.

Copy constructor.

Parameters:
otherThe language tag from which to copy
Soprano::LanguageTag::LanguageTag ( const char *  tag)

Creates a language tag.

Parameters:
tagThe language tag string

Creates a language tag.

Parameters:
tagThe language tag string

Creates a language tag.

Parameters:
tagThe language tag string
Soprano::LanguageTag::LanguageTag ( const QLocale locale) [explicit]

Creates a language tag from a QLocale. If the language is QLocale::C, then an empty LanguageTag is produced.

Parameters:
localethe locale
Soprano::LanguageTag::LanguageTag ( QLocale::Language  lang,
QLocale::Country  country = QLocale::AnyCountry 
)

Creates a language tag from a language and country. If lang is QLocale::C, then an empty LanguageTag is produced.

Parameters:
langthe language code
countrythe country code

Destructor.


Member Function Documentation

LanguageTag& Soprano::LanguageTag::operator= ( const LanguageTag other)

Assigns other to this tag.

bool Soprano::LanguageTag::operator== ( const LanguageTag other) const

Comparison operator. Language tag comparisons are case-insensitive.

Returns:
true if this tag and other are equal.
bool Soprano::LanguageTag::operator!= ( const LanguageTag other) const

Comparison operator. Language tag comparisons are case-insensitive.

Returns:
true if this tag and other differ.
bool Soprano::LanguageTag::operator< ( const LanguageTag other) const

Comparison operator.

Returns:
true if this tag is lexically less than other.
bool Soprano::LanguageTag::operator<= ( const LanguageTag other) const

Comparison operator.

Returns:
true if this tag is lexically less than or equal to other.
bool Soprano::LanguageTag::operator> ( const LanguageTag other) const

Comparison operator.

Returns:
true if this tag is lexically greater than other.
bool Soprano::LanguageTag::operator>= ( const LanguageTag other) const

Comparison operator.

Returns:
true if this tag is lexically greater than or equal to other.
bool Soprano::LanguageTag::matches ( const LanguageTag range,
MatchFilter  scheme = MatchFilterBasic 
) const

Match this language tag against range using the specified filtering scheme.

Parameters:
rangethe range against which to match
schemethe filtering scheme to use
Returns:
true if this tag matches pattern, false if not.
Returns:
true if this language tag is empty.

Determines if this language tag is valid. A valid language tag is divided into subtags that are divided by "-". The tag must adhere the following rules:

  • Each subtag is composed only of characters in the ASCII range [a-zA-Z0-9] (letters and digits), with the exception of the first subtag, which must be composed of letters only
  • No subtags are empty
  • No subtags are longer than 8 characters
  • Single-character subtags cannot end the tag unless after a private use ("x") subtag (e.g. "en-x-i" and "en-x-abcd-i" are legal; "en-x", "en-i", and "en-i-abcd-g" are illegal)
Returns:
true if this language tag is valid
Returns:
the subtag parts that make up this language tag

Converts this LanguageTag to a string.

Returns:
the string representation of this LanguageTag

Converts this LanguageTag to a string formatted according to the case rules in RFC 4647 section 4.4 (page 44).

Returns:
the pretty string representation of this LanguageTag

Converts this LanguageTag to a locale, using the primary language tag and first two-letter language subtag, if any. If the conversion could not be performed, then the "C" QLocale is returned.

Returns:
the converted locale
Note:
QLocale restricts the countries that can be paired with a particular language. If the language-country pair in this tag is not in the QLocale database, or if this language tag does not contain country information, then the most appropriate country will be used for the locale. For example, "de-US" (German as spoken in the United States) is not a valid combination, and the country would be changed to Germany.
Soprano::LanguageTag::operator QString ( ) const [inline]

A convenience operator to convert this LanguageTag to a string.

Returns:
the string representation of this LanguageTag
See also:
toString()

Definition at line 277 of file languagetag.h.

static int Soprano::LanguageTag::lookup ( const QList< LanguageTag > &  choices,
const QList< LanguageTag > &  priority,
LookupFlags  flags = LookupFlagNone,
MatchFilter  scheme = MatchFilterBasic 
) [static]

Compares a language tag against a list of language tags and selects the most suitable tag according to the rules of RFC 4647 Section 3.4.

The arguments consist of choices, a list of tags from which to select, and priority, a list of acceptable language ranges. Both lists must be sorted in descending order of preference.

The matching algorithm works as follows:

  1. For each item in the priority list, the choices list is scanned for matches. The wildcard value "*" is ignored in lookup operations, as it would match any tag. If a match occurs, the lookup is complete and the matching choices list index is returned.
  2. If no match has been found, the last subtag on the current priority item is truncated, and the choices list is scanned again. Single-character subtags are also truncated if they are at the end of the tag. This repeats until there are no subtags remaining. This fallback behavior can be skipped by specifying the LookupFlagsNoFallback flag.
  3. If neither the current priority item nor any of its fallback values matched the choices list, then the next item in the priority list is considered according to the above steps.
  4. If none of the priority items match the choices list, then a value < 0 is returned.
Parameters:
choicesthe list of available language choices
prioritythe language priority list
flagsflags for the lookup operation
schemethe matching scheme to use. RFC 4647 specifies that basic (MatchFilterBasic) processing should be used.
Returns:
the index of the matching language tag in choices, or < 0 if no tag matched.
static int Soprano::LanguageTag::lookup ( const QList< LanguageTag > &  choices,
const LanguageTag priority,
LookupFlags  flags = LookupFlagNone,
MatchFilter  scheme = MatchFilterBasic 
) [static]

A convenience method to select a language tag based on a single search pattern.

Parameters:
choicesthe list of available language choices
prioritythe language range against which to match
flagsflags for the lookup operation
schemethe matching scheme to use. RFC 4647 specifies that basic (MatchFilterBasic) processing should be used.
Returns:
the index of the matching language tag in choices, or < 0 if no tag matched.
See also:
lookup(const QList<LanguageTag> &, const QList<LanguageTag> &, LookupFlags, MatchFilter)

The documentation for this class was generated from the following file: