MessageFormat prepares strings for display to users, * with optional arguments (variables/placeholders). * The arguments can occur in any order, which is necessary for translation * into languages with different grammars. * *
A MessageFormat is constructed from a pattern string * with arguments in {curly braces} which will be replaced by formatted values. * *
MessageFormat differs from the other Format
* classes in that you create a MessageFormat object with one
* of its constructors (not with a createInstance style factory
* method). Factory methods aren't necessary because MessageFormat
* itself doesn't implement locale-specific behavior. Any locale-specific
* behavior is defined by the pattern that you provide and the
* subformats used for inserted arguments.
*
*
Arguments can be named (using identifiers) or numbered (using small ASCII-digit integers). * Some of the API methods work only with argument numbers and throw an exception * if the pattern has named arguments (see {@link #usesNamedArguments()}). * *
An argument might not specify any format type. In this case, * a numeric value is formatted with a default (for the locale) NumberFormat, * and a date/time value is formatted with a default (for the locale) DateFormat. * *
An argument might specify a "simple" type for which the specified * Format object is created, cached and used. * *
An argument might have a "complex" type with nested MessageFormat sub-patterns. * During formatting, one of these sub-messages is selected according to the argument value * and recursively formatted. * *
After construction, a custom Format object can be set for * a top-level argument, overriding the default formatting and parsing behavior * for that argument. * However, custom formatting can be achieved more simply by writing * a typeless argument in the pattern string * and supplying it with a preformatted string value. * *
When formatting, MessageFormat takes a collection of argument values * and writes an output string. * The argument values may be passed as an array * (when the pattern contains only numbered arguments) * or as an array of names and and an array of arguments (which works for both named * and numbered arguments). * *
Each argument is matched with one of the input values by array index or argument name * and formatted according to its pattern specification * (or using a custom Format object if one was set). * A numbered pattern argument is matched with an argument name that contains that number * as an ASCII-decimal-digit string (without leading zero). * *
MessageFormat uses patterns of the following form:
*
* message = messageText (argument messageText)*
* argument = noneArg | simpleArg | complexArg
* complexArg = choiceArg | pluralArg | selectArg | selectordinalArg
*
* noneArg = '{' argNameOrNumber '}'
* simpleArg = '{' argNameOrNumber ',' argType [',' argStyle] '}'
* choiceArg = '{' argNameOrNumber ',' "choice" ',' choiceStyle '}'
* pluralArg = '{' argNameOrNumber ',' "plural" ',' pluralStyle '}'
* selectArg = '{' argNameOrNumber ',' "select" ',' selectStyle '}'
* selectordinalArg = '{' argNameOrNumber ',' "selectordinal" ',' pluralStyle '}'
*
* choiceStyle: see {@link ChoiceFormat}
* pluralStyle: see {@link PluralFormat}
* selectStyle: see {@link SelectFormat}
*
* argNameOrNumber = argName | argNumber
* argName = [^[[:Pattern_Syntax:][:Pattern_White_Space:]]]+
* argNumber = '0' | ('1'..'9' ('0'..'9')*)
*
* argType = "number" | "date" | "time" | "spellout" | "ordinal" | "duration"
* argStyle = "short" | "medium" | "long" | "full" | "integer" | "currency" | "percent" | argStyleText | "::" argSkeletonText
*
*
* Recommendation: Use the real apostrophe (single quote) character * \htmlonly’\endhtmlonly (U+2019) for * human-readable text, and use the ASCII apostrophe ' (U+0027) * only in program syntax, like quoting in MessageFormat. * See the annotations for U+0027 Apostrophe in The Unicode Standard. * *
The choice argument type is deprecated.
* Use plural arguments for proper plural selection,
* and select arguments for simple selection among a fixed set of choices.
*
*
The argType and argStyle values are used to create
* a Format instance for the format element. The following
* table shows how the values map to Format instances. Combinations not
* shown in the table are illegal. Any argStyleText must
* be a valid pattern string for the Format subclass used.
*
*
| argType * | argStyle * | resulting Format object * |
|---|---|---|
| (none) * | null
* | |
number
* | (none) * | NumberFormat.createInstance(getLocale(), status)
* |
integer
* | NumberFormat.createInstance(getLocale(), kNumberStyle, status)
* | |
currency
* | NumberFormat.createCurrencyInstance(getLocale(), status)
* | |
percent
* | NumberFormat.createPercentInstance(getLocale(), status)
* | |
| argStyleText * | new DecimalFormat(argStyleText, new DecimalFormatSymbols(getLocale(), status), status)
* | |
| argSkeletonText * | NumberFormatter::forSkeleton(argSkeletonText, status).locale(getLocale()).toFormat(status)
* | |
date
* | (none) * | DateFormat.createDateInstance(kDefault, getLocale(), status)
* |
short
* | DateFormat.createDateInstance(kShort, getLocale(), status)
* | |
medium
* | DateFormat.createDateInstance(kDefault, getLocale(), status)
* | |
long
* | DateFormat.createDateInstance(kLong, getLocale(), status)
* | |
full
* | DateFormat.createDateInstance(kFull, getLocale(), status)
* | |
| argStyleText * | new SimpleDateFormat(argStyleText, getLocale(), status)
* | |
| argSkeletonText * | DateFormat::createInstanceForSkeleton(argSkeletonText, getLocale(), status)
* | |
time
* | (none) * | DateFormat.createTimeInstance(kDefault, getLocale(), status)
* |
short
* | DateFormat.createTimeInstance(kShort, getLocale(), status)
* | |
medium
* | DateFormat.createTimeInstance(kDefault, getLocale(), status)
* | |
long
* | DateFormat.createTimeInstance(kLong, getLocale(), status)
* | |
full
* | DateFormat.createTimeInstance(kFull, getLocale(), status)
* | |
| argStyleText * | new SimpleDateFormat(argStyleText, getLocale(), status)
* | |
spellout
* | argStyleText (optional) * | new RuleBasedNumberFormat(URBNF_SPELLOUT, getLocale(), status)
*
* |
ordinal
* | argStyleText (optional) * | new RuleBasedNumberFormat(URBNF_ORDINAL, getLocale(), status)
*
* |
duration
* | argStyleText (optional) * | new RuleBasedNumberFormat(URBNF_DURATION, getLocale(), status)
*
* |
* *
Arguments are formatted according to their type, using the default * ICU formatters for those types, unless otherwise specified.
* *There are also several ways to control the formatting.
* *We recommend you use default styles, predefined style values, skeletons, * or preformatted values, but not pattern strings or custom format objects.
* *For more details, see the * ICU User Guide.
* *Here are some examples of usage: * Example 1: * *
* \code
* UErrorCode success = U_ZERO_ERROR;
* GregorianCalendar cal(success);
* Formattable arguments[] = {
* 7L,
* Formattable( (Date) cal.getTime(success), Formattable::kIsDate),
* "a disturbance in the Force"
* };
*
* UnicodeString result;
* MessageFormat::format(
* "At {1,time,::jmm} on {1,date,::dMMMM}, there was {2} on planet {0,number}.",
* arguments, 3, result, success );
*
* cout << "result: " << result << endl;
* //
*
* Typically, the message format will come from resources, and the
* arguments will be dynamically set at runtime.
*
* Example 2: * *
* \code
* success = U_ZERO_ERROR;
* Formattable testArgs[] = {3L, "MyDisk"};
*
* MessageFormat form(
* "The disk \"{1}\" contains {0} file(s).", success );
*
* UnicodeString string;
* FieldPosition fpos = 0;
* cout << "format: " << form.format(testArgs, 2, string, fpos, success ) << endl;
*
* // output, with different testArgs:
* // output: The disk "MyDisk" contains 0 file(s).
* // output: The disk "MyDisk" contains 1 file(s).
* // output: The disk "MyDisk" contains 1,273 file(s).
* \endcode
*
*
*
* For messages that include plural forms, you can use a plural argument: *
* \code
* success = U_ZERO_ERROR;
* MessageFormat msgFmt(
* "{num_files, plural, "
* "=0{There are no files on disk \"{disk_name}\".}"
* "=1{There is one file on disk \"{disk_name}\".}"
* "other{There are # files on disk \"{disk_name}\".}}",
* Locale("en"),
* success);
* FieldPosition fpos = 0;
* Formattable testArgs[] = {0L, "MyDisk"};
* UnicodeString testArgsNames[] = {"num_files", "disk_name"};
* UnicodeString result;
* cout << msgFmt.format(testArgs, testArgsNames, 2, result, fpos, 0, success);
* testArgs[0] = 3L;
* cout << msgFmt.format(testArgs, testArgsNames, 2, result, fpos, 0, success);
* \endcode
* output:
* There are no files on disk "MyDisk".
* There are 3 files on "MyDisk".
*
* See {@link PluralFormat} and {@link PluralRules} for details.
*
* MessageFormats are not synchronized. * It is recommended to create separate format instances for each thread. * If multiple threads access a format concurrently, it must be synchronized * externally. * * @stable ICU 2.0 */ class U_I18N_API MessageFormat : public Format { public: #ifndef U_HIDE_OBSOLETE_API /** * Enum type for kMaxFormat. * @obsolete ICU 3.0. The 10-argument limit was removed as of ICU 2.6, * rendering this enum type obsolete. */ enum EFormatNumber { /** * The maximum number of arguments. * @obsolete ICU 3.0. The 10-argument limit was removed as of ICU 2.6, * rendering this constant obsolete. */ kMaxFormat = 10 }; #endif /* U_HIDE_OBSOLETE_API */ /** * Constructs a new MessageFormat using the given pattern and the * default locale. * * @param pattern Pattern used to construct object. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @stable ICU 2.0 */ MessageFormat(const UnicodeString& pattern, UErrorCode &status); /** * Constructs a new MessageFormat using the given pattern and locale. * @param pattern Pattern used to construct object. * @param newLocale The locale to use for formatting dates and numbers. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @stable ICU 2.0 */ MessageFormat(const UnicodeString& pattern, const Locale& newLocale, UErrorCode& status); /** * Constructs a new MessageFormat using the given pattern and locale. * @param pattern Pattern used to construct object. * @param newLocale The locale to use for formatting dates and numbers. * @param parseError Struct to receive information on the position * of an error within the pattern. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @stable ICU 2.0 */ MessageFormat(const UnicodeString& pattern, const Locale& newLocale, UParseError& parseError, UErrorCode& status); /** * Constructs a new MessageFormat from an existing one. * @stable ICU 2.0 */ MessageFormat(const MessageFormat&); /** * Assignment operator. * @stable ICU 2.0 */ const MessageFormat& operator=(const MessageFormat&); /** * Destructor. * @stable ICU 2.0 */ virtual ~MessageFormat(); /** * Clones this Format object polymorphically. The caller owns the * result and should delete it when done. * @stable ICU 2.0 */ virtual MessageFormat* clone() const override; /** * Returns true if the given Format objects are semantically equal. * Objects of different subclasses are considered unequal. * @param other the object to be compared with. * @return true if the given Format objects are semantically equal. * @stable ICU 2.0 */ virtual bool operator==(const Format& other) const override; /** * Sets the locale to be used for creating argument Format objects. * @param theLocale the new locale value to be set. * @stable ICU 2.0 */ virtual void setLocale(const Locale& theLocale); /** * Gets the locale used for creating argument Format objects. * format information. * @return the locale of the object. * @stable ICU 2.0 */ virtual const Locale& getLocale(void) const; /** * Applies the given pattern string to this message format. * * @param pattern The pattern to be applied. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @stable ICU 2.0 */ virtual void applyPattern(const UnicodeString& pattern, UErrorCode& status); /** * Applies the given pattern string to this message format. * * @param pattern The pattern to be applied. * @param parseError Struct to receive information on the position * of an error within the pattern. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @stable ICU 2.0 */ virtual void applyPattern(const UnicodeString& pattern, UParseError& parseError, UErrorCode& status); /** * Sets the UMessagePatternApostropheMode and the pattern used by this message format. * Parses the pattern and caches Format objects for simple argument types. * Patterns and their interpretation are specified in the * class description. *
* This method is best used only once on a given object to avoid confusion about the mode, * and after constructing the object with an empty pattern string to minimize overhead. * * @param pattern The pattern to be applied. * @param aposMode The new apostrophe mode. * @param parseError Struct to receive information on the position * of an error within the pattern. * Can be nullptr. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @stable ICU 4.8 */ virtual void applyPattern(const UnicodeString& pattern, UMessagePatternApostropheMode aposMode, UParseError* parseError, UErrorCode& status); /** * @return this instance's UMessagePatternApostropheMode. * @stable ICU 4.8 */ UMessagePatternApostropheMode getApostropheMode() const { return msgPattern.getApostropheMode(); } /** * Returns a pattern that can be used to recreate this object. * * @param appendTo Output parameter to receive the pattern. * Result is appended to existing contents. * @return Reference to 'appendTo' parameter. * @stable ICU 2.0 */ virtual UnicodeString& toPattern(UnicodeString& appendTo) const; /** * Sets subformats. * See the class description about format numbering. * The caller should not delete the Format objects after this call. * The array formatsToAdopt is not itself adopted. Its * ownership is retained by the caller. If the call fails because * memory cannot be allocated, then the formats will be deleted * by this method, and this object will remain unchanged. * *
If this format uses named arguments, the new formats are discarded * and this format remains unchanged. * * @stable ICU 2.0 * @param formatsToAdopt the format to be adopted. * @param count the size of the array. */ virtual void adoptFormats(Format** formatsToAdopt, int32_t count); /** * Sets subformats. * See the class description about format numbering. * Each item in the array is cloned into the internal array. * If the call fails because memory cannot be allocated, then this * object will remain unchanged. * *
If this format uses named arguments, the new formats are discarded * and this format remains unchanged. * * @stable ICU 2.0 * @param newFormats the new format to be set. * @param cnt the size of the array. */ virtual void setFormats(const Format** newFormats, int32_t cnt); /** * Sets one subformat. * See the class description about format numbering. * The caller should not delete the Format object after this call. * If the number is over the number of formats already set, * the item will be deleted and ignored. * *
If this format uses named arguments, the new format is discarded * and this format remains unchanged. * * @stable ICU 2.0 * @param formatNumber index of the subformat. * @param formatToAdopt the format to be adopted. */ virtual void adoptFormat(int32_t formatNumber, Format* formatToAdopt); /** * Sets one subformat. * See the class description about format numbering. * If the number is over the number of formats already set, * the item will be ignored. * @param formatNumber index of the subformat. * @param format the format to be set. * @stable ICU 2.0 */ virtual void setFormat(int32_t formatNumber, const Format& format); /** * Gets format names. This function returns formatNames in StringEnumerations * which can be used with getFormat() and setFormat() to export formattable * array from current MessageFormat to another. It is the caller's responsibility * to delete the returned formatNames. * @param status output param set to success/failure code. * @stable ICU 4.0 */ virtual StringEnumeration* getFormatNames(UErrorCode& status); /** * Gets subformat pointer for given format name. * This function supports both named and numbered * arguments. If numbered, the formatName is the * corresponding UnicodeStrings (e.g. "0", "1", "2"...). * The returned Format object should not be deleted by the caller, * nor should the pointer of other object . The pointer and its * contents remain valid only until the next call to any method * of this class is made with this object. * @param formatName the name or number specifying a format * @param status output param set to success/failure code. * @stable ICU 4.0 */ virtual Format* getFormat(const UnicodeString& formatName, UErrorCode& status); /** * Sets one subformat for given format name. * See the class description about format name. * This function supports both named and numbered * arguments-- if numbered, the formatName is the * corresponding UnicodeStrings (e.g. "0", "1", "2"...). * If there is no matched formatName or wrong type, * the item will be ignored. * @param formatName Name of the subformat. * @param format the format to be set. * @param status output param set to success/failure code. * @stable ICU 4.0 */ virtual void setFormat(const UnicodeString& formatName, const Format& format, UErrorCode& status); /** * Sets one subformat for given format name. * See the class description about format name. * This function supports both named and numbered * arguments-- if numbered, the formatName is the * corresponding UnicodeStrings (e.g. "0", "1", "2"...). * If there is no matched formatName or wrong type, * the item will be ignored. * The caller should not delete the Format object after this call. * @param formatName Name of the subformat. * @param formatToAdopt Format to be adopted. * @param status output param set to success/failure code. * @stable ICU 4.0 */ virtual void adoptFormat(const UnicodeString& formatName, Format* formatToAdopt, UErrorCode& status); /** * Gets an array of subformats of this object. The returned array * should not be deleted by the caller, nor should the pointers * within the array. The array and its contents remain valid only * until the next call to this format. See the class description * about format numbering. * * @param count output parameter to receive the size of the array * @return an array of count Format* objects, or nullptr if out of * memory. Any or all of the array elements may be nullptr. * @stable ICU 2.0 */ virtual const Format** getFormats(int32_t& count) const; using Format::format; /** * Formats the given array of arguments into a user-readable string. * Does not take ownership of the Formattable* array or its contents. * *
If this format uses named arguments, appendTo is unchanged and * status is set to U_ILLEGAL_ARGUMENT_ERROR. * * @param source An array of objects to be formatted. * @param count The number of elements of 'source'. * @param appendTo Output parameter to receive result. * Result is appended to existing contents. * @param ignore Not used; inherited from base class API. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @return Reference to 'appendTo' parameter. * @stable ICU 2.0 */ UnicodeString& format(const Formattable* source, int32_t count, UnicodeString& appendTo, FieldPosition& ignore, UErrorCode& status) const; /** * Formats the given array of arguments into a user-readable string * using the given pattern. * *
If this format uses named arguments, appendTo is unchanged and * status is set to U_ILLEGAL_ARGUMENT_ERROR. * * @param pattern The pattern. * @param arguments An array of objects to be formatted. * @param count The number of elements of 'source'. * @param appendTo Output parameter to receive result. * Result is appended to existing contents. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @return Reference to 'appendTo' parameter. * @stable ICU 2.0 */ static UnicodeString& format(const UnicodeString& pattern, const Formattable* arguments, int32_t count, UnicodeString& appendTo, UErrorCode& status); /** * Formats the given array of arguments into a user-readable * string. The array must be stored within a single Formattable * object of type kArray. If the Formattable object type is not of * type kArray, then returns a failing UErrorCode. * *
If this format uses named arguments, appendTo is unchanged and * status is set to U_ILLEGAL_ARGUMENT_ERROR. * * @param obj A Formattable of type kArray containing * arguments to be formatted. * @param appendTo Output parameter to receive result. * Result is appended to existing contents. * @param pos On input: an alignment field, if desired. * On output: the offsets of the alignment field. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @return Reference to 'appendTo' parameter. * @stable ICU 2.0 */ virtual UnicodeString& format(const Formattable& obj, UnicodeString& appendTo, FieldPosition& pos, UErrorCode& status) const override; /** * Formats the given array of arguments into a user-defined argument name * array. This function supports both named and numbered * arguments-- if numbered, the formatName is the * corresponding UnicodeStrings (e.g. "0", "1", "2"...). * * @param argumentNames argument name array * @param arguments An array of objects to be formatted. * @param count The number of elements of 'argumentNames' and * arguments. The number of argumentNames and arguments * must be the same. * @param appendTo Output parameter to receive result. * Result is appended to existing contents. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @return Reference to 'appendTo' parameter. * @stable ICU 4.0 */ UnicodeString& format(const UnicodeString* argumentNames, const Formattable* arguments, int32_t count, UnicodeString& appendTo, UErrorCode& status) const; /** * Parses the given string into an array of output arguments. * * @param source String to be parsed. * @param pos On input, starting position for parse. On output, * final position after parse. Unchanged if parse * fails. * @param count Output parameter to receive the number of arguments * parsed. * @return an array of parsed arguments. The caller owns both * the array and its contents. * @stable ICU 2.0 */ virtual Formattable* parse(const UnicodeString& source, ParsePosition& pos, int32_t& count) const; /** * Parses the given string into an array of output arguments. * *
If this format uses named arguments, status is set to * U_ARGUMENT_TYPE_MISMATCH. * * @param source String to be parsed. * @param count Output param to receive size of returned array. * @param status Input/output error code. If the * pattern cannot be parsed, set to failure code. * @return an array of parsed arguments. The caller owns both * the array and its contents. Returns nullptr if status is not U_ZERO_ERROR. * * @stable ICU 2.0 */ virtual Formattable* parse(const UnicodeString& source, int32_t& count, UErrorCode& status) const; /** * Parses the given string into an array of output arguments * stored within a single Formattable of type kArray. * * @param source The string to be parsed into an object. * @param result Formattable to be set to the parse result. * If parse fails, return contents are undefined. * @param pos On input, starting position for parse. On output, * final position after parse. Unchanged if parse * fails. * @stable ICU 2.0 */ virtual void parseObject(const UnicodeString& source, Formattable& result, ParsePosition& pos) const override; /** * Convert an 'apostrophe-friendly' pattern into a standard * pattern. Standard patterns treat all apostrophes as * quotes, which is problematic in some languages, e.g. * French, where apostrophe is commonly used. This utility * assumes that only an unpaired apostrophe immediately before * a brace is a true quote. Other unpaired apostrophes are paired, * and the resulting standard pattern string is returned. * *
Note it is not guaranteed that the returned pattern * is indeed a valid pattern. The only effect is to convert * between patterns having different quoting semantics. * * @param pattern the 'apostrophe-friendly' patttern to convert * @param status Input/output error code. If the pattern * cannot be parsed, the failure code is set. * @return the standard equivalent of the original pattern * @stable ICU 3.4 */ static UnicodeString autoQuoteApostrophe(const UnicodeString& pattern, UErrorCode& status); /** * Returns true if this MessageFormat uses named arguments, * and false otherwise. See class description. * * @return true if named arguments are used. * @stable ICU 4.0 */ UBool usesNamedArguments() const; #ifndef U_HIDE_INTERNAL_API /** * This API is for ICU internal use only. * Please do not use it. * * Returns argument types count in the parsed pattern. * Used to distinguish pattern "{0} d" and "d". * * @return The number of formattable types in the pattern * @internal */ int32_t getArgTypeCount() const; #endif /* U_HIDE_INTERNAL_API */ /** * Returns a unique class ID POLYMORPHICALLY. Pure virtual override. * This method is to implement a simple version of RTTI, since not all * C++ compilers support genuine RTTI. Polymorphic operator==() and * clone() methods call this method. * * @return The class ID for this object. All objects of a * given class have the same class ID. Objects of * other classes have different class IDs. * @stable ICU 2.0 */ virtual UClassID getDynamicClassID(void) const override; /** * Return the class ID for this class. This is useful only for * comparing to a return value from getDynamicClassID(). For example: *
* . Base* polymorphic_pointer = createPolymorphicObject();
* . if (polymorphic_pointer->getDynamicClassID() ==
* . Derived::getStaticClassID()) ...
*
* @return The class ID for all objects of this class.
* @stable ICU 2.0
*/
static UClassID U_EXPORT2 getStaticClassID(void);
#ifndef U_HIDE_INTERNAL_API
/**
* Compares two Format objects. This is used for constructing the hash
* tables.
*
* @param left pointer to a Format object. Must not be nullptr.
* @param right pointer to a Format object. Must not be nullptr.
*
* @return whether the two objects are the same
* @internal
*/
static UBool equalFormats(const void* left, const void* right);
#endif /* U_HIDE_INTERNAL_API */
private:
Locale fLocale;
MessagePattern msgPattern;
Format** formatAliases; // see getFormats
int32_t formatAliasesCapacity;
MessageFormat() = delete; // default constructor not implemented
/**
* This provider helps defer instantiation of a PluralRules object
* until we actually need to select a keyword.
* For example, if the number matches an explicit-value selector like "=1"
* we do not need any PluralRules.
*/
class U_I18N_API PluralSelectorProvider : public PluralFormat::PluralSelector {
public:
PluralSelectorProvider(const MessageFormat &mf, UPluralType type);
virtual ~PluralSelectorProvider();
virtual UnicodeString select(void *ctx, double number, UErrorCode& ec) const override;
void reset();
private:
const MessageFormat &msgFormat;
PluralRules* rules;
UPluralType type;
};
/**
* A MessageFormat formats an array of arguments. Each argument
* has an expected type, based on the pattern. For example, if
* the pattern contains the subformat "{3,number,integer}", then
* we expect argument 3 to have type Formattable::kLong. This
* array needs to grow dynamically if the MessageFormat is
* modified.
*/
Formattable::Type* argTypes;
int32_t argTypeCount;
int32_t argTypeCapacity;
/**
* true if there are different argTypes for the same argument.
* This only matters when the MessageFormat is used in the plain C (umsg_xxx) API
* where the pattern argTypes determine how the va_arg list is read.
*/
UBool hasArgTypeConflicts;
// Variable-size array management
UBool allocateArgTypes(int32_t capacity, UErrorCode& status);
/**
* Default Format objects used when no format is specified and a
* numeric or date argument is formatted. These are volatile
* cache objects maintained only for performance. They do not
* participate in operator=(), copy constructor(), nor
* operator==().
*/
NumberFormat* defaultNumberFormat;
DateFormat* defaultDateFormat;
UHashtable* cachedFormatters;
UHashtable* customFormatArgStarts;
PluralSelectorProvider pluralProvider;
PluralSelectorProvider ordinalProvider;
/**
* Method to retrieve default formats (or nullptr on failure).
* These are semantically const, but may modify *this.
*/
const NumberFormat* getDefaultNumberFormat(UErrorCode&) const;
const DateFormat* getDefaultDateFormat(UErrorCode&) const;
/**
* Finds the word s, in the keyword list and returns the located index.
* @param s the keyword to be searched for.
* @param list the list of keywords to be searched with.
* @return the index of the list which matches the keyword s.
*/
static int32_t findKeyword( const UnicodeString& s,
const char16_t * const *list);
/**
* Thin wrapper around the format(... AppendableWrapper ...) variant.
* Wraps the destination UnicodeString into an AppendableWrapper and
* supplies default values for some other parameters.
*/
UnicodeString& format(const Formattable* arguments,
const UnicodeString *argumentNames,
int32_t cnt,
UnicodeString& appendTo,
FieldPosition* pos,
UErrorCode& status) const;
/**
* Formats the arguments and writes the result into the
* AppendableWrapper, updates the field position.
*
* @param msgStart Index to msgPattern part to start formatting from.
* @param plNumber nullptr except when formatting a plural argument sub-message
* where a '#' is replaced by the format string for this number.
* @param arguments The formattable objects array. (Must not be nullptr.)
* @param argumentNames nullptr if numbered values are used. Otherwise the same
* length as "arguments", and each entry is the name of the
* corresponding argument in "arguments".
* @param cnt The length of arguments (and of argumentNames if that is not nullptr).
* @param appendTo Output parameter to receive the result.
* The result string is appended to existing contents.
* @param pos Field position status.
* @param success The error code status.
*/
void format(int32_t msgStart,
const void *plNumber,
const Formattable* arguments,
const UnicodeString *argumentNames,
int32_t cnt,
AppendableWrapper& appendTo,
FieldPosition* pos,
UErrorCode& success) const;
UnicodeString getArgName(int32_t partIndex);
void setArgStartFormat(int32_t argStart, Format* formatter, UErrorCode& status);
void setCustomArgStartFormat(int32_t argStart, Format* formatter, UErrorCode& status);
int32_t nextTopLevelArgStart(int32_t partIndex) const;
UBool argNameMatches(int32_t partIndex, const UnicodeString& argName, int32_t argNumber);
void cacheExplicitFormats(UErrorCode& status);
Format* createAppropriateFormat(UnicodeString& type,
UnicodeString& style,
Formattable::Type& formattableType,
UParseError& parseError,
UErrorCode& ec);
const Formattable* getArgFromListByName(const Formattable* arguments,
const UnicodeString *argumentNames,
int32_t cnt, UnicodeString& name) const;
Formattable* parse(int32_t msgStart,
const UnicodeString& source,
ParsePosition& pos,
int32_t& count,
UErrorCode& ec) const;
FieldPosition* updateMetaData(AppendableWrapper& dest, int32_t prevLength,
FieldPosition* fp, const Formattable* argId) const;
/**
* Finds the "other" sub-message.
* @param partIndex the index of the first PluralFormat argument style part.
* @return the "other" sub-message start part index.
*/
int32_t findOtherSubMessage(int32_t partIndex) const;
/**
* Returns the ARG_START index of the first occurrence of the plural number in a sub-message.
* Returns -1 if it is a REPLACE_NUMBER.
* Returns 0 if there is neither.
*/
int32_t findFirstPluralNumberArg(int32_t msgStart, const UnicodeString &argName) const;
Format* getCachedFormatter(int32_t argumentNumber) const;
UnicodeString getLiteralStringUntilNextArgument(int32_t from) const;
void copyObjects(const MessageFormat& that, UErrorCode& ec);
void formatComplexSubMessage(int32_t msgStart,
const void *plNumber,
const Formattable* arguments,
const UnicodeString *argumentNames,
int32_t cnt,
AppendableWrapper& appendTo,
UErrorCode& success) const;
/**
* Convenience method that ought to be in NumberFormat
*/
NumberFormat* createIntegerFormat(const Locale& locale, UErrorCode& status) const;
/**
* Returns array of argument types in the parsed pattern
* for use in C API. Only for the use of umsg_vformat(). Not
* for public consumption.
* @param listCount Output parameter to receive the size of array
* @return The array of formattable types in the pattern
*/
const Formattable::Type* getArgTypeList(int32_t& listCount) const {
listCount = argTypeCount;
return argTypes;
}
/**
* Resets the internal MessagePattern, and other associated caches.
*/
void resetPattern();
/**
* A DummyFormatter that we use solely to store a nullptr value. UHash does
* not support storing nullptr values.
*/
class U_I18N_API DummyFormat : public Format {
public:
virtual bool operator==(const Format&) const override;
virtual DummyFormat* clone() const override;
virtual UnicodeString& format(const Formattable& obj,
UnicodeString& appendTo,
UErrorCode& status) const;
virtual UnicodeString& format(const Formattable&,
UnicodeString& appendTo,
FieldPosition&,
UErrorCode& status) const override;
virtual UnicodeString& format(const Formattable& obj,
UnicodeString& appendTo,
FieldPositionIterator* posIter,
UErrorCode& status) const override;
virtual void parseObject(const UnicodeString&,
Formattable&,
ParsePosition&) const override;
};
friend class MessageFormatAdapter; // getFormatTypeList() access
};
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */
#endif /* U_SHOW_CPLUSPLUS_API */
#endif // _MSGFMT
//eof