icuSources/common/unicode/localebuilder.h

   1 // © 2018 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html#License
   3 #ifndef __LOCALEBUILDER_H__
   4 #define __LOCALEBUILDER_H__
   5
   6 #include "unicode/utypes.h"
   7
   8 #if U_SHOW_CPLUSPLUS_API
   9
  10 #include "unicode/locid.h"
  11 #include "unicode/localematcher.h"
  12 #include "unicode/stringpiece.h"
  13 #include "unicode/uobject.h"
  14
  15 #ifndef U_HIDE_DRAFT_API
  16 /**
  17  * \file
  18  * \brief C++ API: Builder API for Locale
  19  */
  20
  21 U_NAMESPACE_BEGIN
  22 class CharString;
  23
  24 /**
  25  * <code>LocaleBuilder</code> is used to build instances of <code>Locale</code>
  26  * from values configured by the setters.  Unlike the <code>Locale</code>
  27  * constructors, the <code>LocaleBuilder</code> checks if a value configured by a
  28  * setter satisfies the syntax requirements defined by the <code>Locale</code>
  29  * class.  A <code>Locale</code> object created by a <code>LocaleBuilder</code> is
  30  * well-formed and can be transformed to a well-formed IETF BCP 47 language tag
  31  * without losing information.
  32  *
  33  * <p>The following example shows how to create a <code>Locale</code> object
  34  * with the <code>LocaleBuilder</code>.
  35  * <blockquote>
  36  * <pre>
  37  *     UErrorCode status = U_ZERO_ERROR;
  38  *     Locale aLocale = LocaleBuilder()
  39  *                          .setLanguage("sr")
  40  *                          .setScript("Latn")
  41  *                          .setRegion("RS")
  42  *                          .build(status);
  43  *     if (U_SUCCESS(status)) {
  44  *       // ...
  45  *     }
  46  * </pre>
  47  * </blockquote>
  48  *
  49  * <p>LocaleBuilders can be reused; <code>clear()</code> resets all
  50  * fields to their default values.
  51  *
  52  * <p>LocaleBuilder tracks errors in an internal UErrorCode. For all setters,
  53  * except setLanguageTag and setLocale, LocaleBuilder will return immediately
  54  * if the internal UErrorCode is in error state.
  55  * To reset internal state and error code, call clear method.
  56  * The setLanguageTag and setLocale method will first clear the internal
  57  * UErrorCode, then track the error of the validation of the input parameter
  58  * into the internal UErrorCode.
  59  *
  60  * @draft ICU 64
  61  */
  62 class U_COMMON_API LocaleBuilder : public UObject {
  63 public:
  64     /**
  65      * Constructs an empty LocaleBuilder. The default value of all
  66      * fields, extensions, and private use information is the
  67      * empty string.
  68      *
  69      * @draft ICU 64
  70      */
  71     LocaleBuilder();
  72
  73     /**
  74      * Destructor
  75      * @draft ICU 64
  76      */
  77     virtual ~LocaleBuilder();
  78
  79     /**
  80      * Resets the <code>LocaleBuilder</code> to match the provided
  81      * <code>locale</code>.  Existing state is discarded.
  82      *
  83      * <p>All fields of the locale must be well-formed.
  84      * <p>This method clears the internal UErrorCode.
  85      *
  86      * @param locale the locale
  87      * @return This builder.
  88      *
  89      * @draft ICU 64
  90      */
  91     LocaleBuilder& setLocale(const Locale& locale);
  92
  93     /**
  94      * Resets the LocaleBuilder to match the provided
  95      * [Unicode Locale Identifier](http://www.unicode.org/reports/tr35/tr35.html#unicode_locale_id) .
  96      * Discards the existing state. the empty string cause the builder to be
  97      * reset, like {@link #clear}.  Grandfathered tags are converted to their
  98      * canonical form before being processed.  Otherwise, the <code>language
  99      * tag</code> must be well-formed, or else the build() method will later
 100      * report an U_ILLEGAL_ARGUMENT_ERROR.
 101      *
 102      * <p>This method clears the internal UErrorCode.
 103      *
 104      * @param tag the language tag, defined as
 105      *   [unicode_locale_id](http://www.unicode.org/reports/tr35/tr35.html#unicode_locale_id).
 106      * @return This builder.
 107      * @draft ICU 64
 108      */
 109     LocaleBuilder& setLanguageTag(StringPiece tag);
 110
 111     /**
 112      * Sets the language.  If <code>language</code> is the empty string, the
 113      * language in this <code>LocaleBuilder</code> is removed. Otherwise, the
 114      * <code>language</code> must be well-formed, or else the build() method will
 115      * later report an U_ILLEGAL_ARGUMENT_ERROR.
 116      *
 117      * <p>The syntax of language value is defined as
 118      * [unicode_language_subtag](http://www.unicode.org/reports/tr35/tr35.html#unicode_language_subtag).
 119      *
 120      * @param language the language
 121      * @return This builder.
 122      * @draft ICU 64
 123      */
 124     LocaleBuilder& setLanguage(StringPiece language);
 125
 126     /**
 127      * Sets the script. If <code>script</code> is the empty string, the script in
 128      * this <code>LocaleBuilder</code> is removed.
 129      * Otherwise, the <code>script</code> must be well-formed, or else the build()
 130      * method will later report an U_ILLEGAL_ARGUMENT_ERROR.
 131      *
 132      * <p>The script value is a four-letter script code as
 133      * [unicode_script_subtag](http://www.unicode.org/reports/tr35/tr35.html#unicode_script_subtag)
 134      * defined by ISO 15924
 135      *
 136      * @param script the script
 137      * @return This builder.
 138      * @draft ICU 64
 139      */
 140     LocaleBuilder& setScript(StringPiece script);
 141
 142     /**
 143      * Sets the region.  If region is the empty string, the region in this
 144      * <code>LocaleBuilder</code> is removed. Otherwise, the <code>region</code>
 145      * must be well-formed, or else the build() method will later report an
 146      * U_ILLEGAL_ARGUMENT_ERROR.
 147      *
 148      * <p>The region value is defined by
 149      *  [unicode_region_subtag](http://www.unicode.org/reports/tr35/tr35.html#unicode_region_subtag)
 150      * as a two-letter ISO 3166 code or a three-digit UN M.49 area code.
 151      *
 152      * <p>The region value in the <code>Locale</code> created by the
 153      * <code>LocaleBuilder</code> is always normalized to upper case.
 154      *
 155      * @param region the region
 156      * @return This builder.
 157      * @draft ICU 64
 158      */
 159     LocaleBuilder& setRegion(StringPiece region);
 160
 161     /**
 162      * Sets the variant.  If variant is the empty string, the variant in this
 163      * <code>LocaleBuilder</code> is removed.  Otherwise, the <code>variant</code>
 164      * must be well-formed, or else the build() method will later report an
 165      * U_ILLEGAL_ARGUMENT_ERROR.
 166      *
 167      * <p><b>Note:</b> This method checks if <code>variant</code>
 168      * satisfies the
 169      * [unicode_variant_subtag](http://www.unicode.org/reports/tr35/tr35.html#unicode_variant_subtag)
 170      * syntax requirements, and normalizes the value to lowercase letters. However,
 171      * the <code>Locale</code> class does not impose any syntactic
 172      * restriction on variant. To set an ill-formed variant, use a Locale constructor.
 173      * If there are multiple unicode_variant_subtag, the caller must concatenate
 174      * them with '-' as separator (ex: "foobar-fibar").
 175      *
 176      * @param variant the variant
 177      * @return This builder.
 178      * @draft ICU 64
 179      */
 180     LocaleBuilder& setVariant(StringPiece variant);
 181
 182     /**
 183      * Sets the extension for the given key. If the value is the empty string,
 184      * the extension is removed.  Otherwise, the <code>key</code> and
 185      * <code>value</code> must be well-formed, or else the build() method will
 186      * later report an U_ILLEGAL_ARGUMENT_ERROR.
 187      *
 188      * <p><b>Note:</b> The key ('u') is used for the Unicode locale extension.
 189      * Setting a value for this key replaces any existing Unicode locale key/type
 190      * pairs with those defined in the extension.
 191      *
 192      * <p><b>Note:</b> The key ('x') is used for the private use code. To be
 193      * well-formed, the value for this key needs only to have subtags of one to
 194      * eight alphanumeric characters, not two to eight as in the general case.
 195      *
 196      * @param key the extension key
 197      * @param value the extension value
 198      * @return This builder.
 199      * @draft ICU 64
 200      */
 201     LocaleBuilder& setExtension(char key, StringPiece value);
 202
 203     /**
 204      * Sets the Unicode locale keyword type for the given key. If the type
 205      * StringPiece is constructed with a nullptr, the keyword is removed.
 206      * If the type is the empty string, the keyword is set without type subtags.
 207      * Otherwise, the key and type must be well-formed, or else the build()
 208      * method will later report an U_ILLEGAL_ARGUMENT_ERROR.
 209      *
 210      * <p>Keys and types are converted to lower case.
 211      *
 212      * <p><b>Note</b>:Setting the 'u' extension via {@link #setExtension}
 213      * replaces all Unicode locale keywords with those defined in the
 214      * extension.
 215      *
 216      * @param key the Unicode locale key
 217      * @param type the Unicode locale type
 218      * @return This builder.
 219      * @draft ICU 64
 220      */
 221     LocaleBuilder& setUnicodeLocaleKeyword(
 222         StringPiece key, StringPiece type);
 223
 224     /**
 225      * Adds a unicode locale attribute, if not already present, otherwise
 226      * has no effect.  The attribute must not be empty string and must be
 227      * well-formed or U_ILLEGAL_ARGUMENT_ERROR will be set to status
 228      * during the build() call.
 229      *
 230      * @param attribute the attribute
 231      * @return This builder.
 232      * @draft ICU 64
 233      */
 234     LocaleBuilder& addUnicodeLocaleAttribute(StringPiece attribute);
 235
 236     /**
 237      * Removes a unicode locale attribute, if present, otherwise has no
 238      * effect.  The attribute must not be empty string and must be well-formed
 239      * or U_ILLEGAL_ARGUMENT_ERROR will be set to status during the build() call.
 240      *
 241      * <p>Attribute comparison for removal is case-insensitive.
 242      *
 243      * @param attribute the attribute
 244      * @return This builder.
 245      * @draft ICU 64
 246      */
 247     LocaleBuilder& removeUnicodeLocaleAttribute(StringPiece attribute);
 248
 249     /**
 250      * Resets the builder to its initial, empty state.
 251      * <p>This method clears the internal UErrorCode.
 252      *
 253      * @return this builder
 254      * @draft ICU 64
 255      */
 256     LocaleBuilder& clear();
 257
 258     /**
 259      * Resets the extensions to their initial, empty state.
 260      * Language, script, region and variant are unchanged.
 261      *
 262      * @return this builder
 263      * @draft ICU 64
 264      */
 265     LocaleBuilder& clearExtensions();
 266
 267     /**
 268      * Returns an instance of <code>Locale</code> created from the fields set
 269      * on this builder.
 270      * If any set methods or during the build() call require memory allocation
 271      * but fail U_MEMORY_ALLOCATION_ERROR will be set to status.
 272      * If any of the fields set by the setters are not well-formed, the status
 273      * will be set to U_ILLEGAL_ARGUMENT_ERROR. The state of the builder will
 274      * not change after the build() call and the caller is free to keep using
 275      * the same builder to build more locales.
 276      *
 277      * @return a new Locale
 278      * @draft ICU 64
 279      */
 280     Locale build(UErrorCode& status);
 281
 282 #ifndef U_HIDE_DRAFT_API
 283     /**
 284      * Sets the UErrorCode if an error occurred while recording sets.
 285      * Preserves older error codes in the outErrorCode.
 286      * @param outErrorCode Set to an error code that occurred while setting subtags.
 287      *                  Unchanged if there is no such error or if outErrorCode
 288      *                  already contained an error.
 289      * @return TRUE if U_FAILURE(outErrorCode)
 290      * @draft ICU 65
 291      */
 292     UBool copyErrorTo(UErrorCode &outErrorCode) const;
 293 #endif  /* U_HIDE_DRAFT_API */
 294
 295 private:
 296     friend class LocaleMatcher::Result;
 297
 298     void copyExtensionsFrom(const Locale& src, UErrorCode& errorCode);
 299
 300     UErrorCode status_;
 301     char language_[9];
 302     char script_[5];
 303     char region_[4];
 304     CharString *variant_;  // Pointer not object so we need not #include internal charstr.h.
 305     icu::Locale *extensions_;  // Pointer not object. Storage for all other fields.
 306
 307 };
 308
 309 U_NAMESPACE_END
 310
 311 #endif  // U_HIDE_DRAFT_API
 312
 313 #endif /* U_SHOW_CPLUSPLUS_API */
 314
 315 #endif  // __LOCALEBUILDER_H__