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