API/JSValueRef.h

   1 /*
   2  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef JSValueRef_h
  27 #define JSValueRef_h
  28
  29 #include <JavaScriptCore/JSBase.h>
  30 #include <JavaScriptCore/WebKitAvailability.h>
  31
  32 #ifndef __cplusplus
  33 #include <stdbool.h>
  34 #endif
  35
  36 /*!
  37 @enum JSType
  38 @abstract     A constant identifying the type of a JSValue.
  39 @constant     kJSTypeUndefined  The unique undefined value.
  40 @constant     kJSTypeNull       The unique null value.
  41 @constant     kJSTypeBoolean    A primitive boolean value, one of true or false.
  42 @constant     kJSTypeNumber     A primitive number value.
  43 @constant     kJSTypeString     A primitive string value.
  44 @constant     kJSTypeObject     An object value (meaning that this JSValueRef is a JSObjectRef).
  45 */
  46 typedef enum {
  47     kJSTypeUndefined,
  48     kJSTypeNull,
  49     kJSTypeBoolean,
  50     kJSTypeNumber,
  51     kJSTypeString,
  52     kJSTypeObject
  53 } JSType;
  54
  55 #ifdef __cplusplus
  56 extern "C" {
  57 #endif
  58
  59 /*!
  60 @function
  61 @abstract       Returns a JavaScript value's type.
  62 @param ctx  The execution context to use.
  63 @param value    The JSValue whose type you want to obtain.
  64 @result         A value of type JSType that identifies value's type.
  65 */
  66 JS_EXPORT JSType JSValueGetType(JSContextRef ctx, JSValueRef value);
  67
  68 /*!
  69 @function
  70 @abstract       Tests whether a JavaScript value's type is the undefined type.
  71 @param ctx  The execution context to use.
  72 @param value    The JSValue to test.
  73 @result         true if value's type is the undefined type, otherwise false.
  74 */
  75 JS_EXPORT bool JSValueIsUndefined(JSContextRef ctx, JSValueRef value);
  76
  77 /*!
  78 @function
  79 @abstract       Tests whether a JavaScript value's type is the null type.
  80 @param ctx  The execution context to use.
  81 @param value    The JSValue to test.
  82 @result         true if value's type is the null type, otherwise false.
  83 */
  84 JS_EXPORT bool JSValueIsNull(JSContextRef ctx, JSValueRef value);
  85
  86 /*!
  87 @function
  88 @abstract       Tests whether a JavaScript value's type is the boolean type.
  89 @param ctx  The execution context to use.
  90 @param value    The JSValue to test.
  91 @result         true if value's type is the boolean type, otherwise false.
  92 */
  93 JS_EXPORT bool JSValueIsBoolean(JSContextRef ctx, JSValueRef value);
  94
  95 /*!
  96 @function
  97 @abstract       Tests whether a JavaScript value's type is the number type.
  98 @param ctx  The execution context to use.
  99 @param value    The JSValue to test.
 100 @result         true if value's type is the number type, otherwise false.
 101 */
 102 JS_EXPORT bool JSValueIsNumber(JSContextRef ctx, JSValueRef value);
 103
 104 /*!
 105 @function
 106 @abstract       Tests whether a JavaScript value's type is the string type.
 107 @param ctx  The execution context to use.
 108 @param value    The JSValue to test.
 109 @result         true if value's type is the string type, otherwise false.
 110 */
 111 JS_EXPORT bool JSValueIsString(JSContextRef ctx, JSValueRef value);
 112
 113 /*!
 114 @function
 115 @abstract       Tests whether a JavaScript value's type is the object type.
 116 @param ctx  The execution context to use.
 117 @param value    The JSValue to test.
 118 @result         true if value's type is the object type, otherwise false.
 119 */
 120 JS_EXPORT bool JSValueIsObject(JSContextRef ctx, JSValueRef value);
 121
 122 /*!
 123 @function
 124 @abstract Tests whether a JavaScript value is an object with a given class in its class chain.
 125 @param ctx The execution context to use.
 126 @param value The JSValue to test.
 127 @param jsClass The JSClass to test against.
 128 @result true if value is an object and has jsClass in its class chain, otherwise false.
 129 */
 130 JS_EXPORT bool JSValueIsObjectOfClass(JSContextRef ctx, JSValueRef value, JSClassRef jsClass);
 131
 132 /* Comparing values */
 133
 134 /*!
 135 @function
 136 @abstract Tests whether two JavaScript values are equal, as compared by the JS == operator.
 137 @param ctx The execution context to use.
 138 @param a The first value to test.
 139 @param b The second value to test.
 140 @param exception A pointer to a JSValueRef in which to store an exception, if any. Pass NULL if you do not care to store an exception.
 141 @result true if the two values are equal, false if they are not equal or an exception is thrown.
 142 */
 143 JS_EXPORT bool JSValueIsEqual(JSContextRef ctx, JSValueRef a, JSValueRef b, JSValueRef* exception);
 144
 145 /*!
 146 @function
 147 @abstract       Tests whether two JavaScript values are strict equal, as compared by the JS === operator.
 148 @param ctx  The execution context to use.
 149 @param a        The first value to test.
 150 @param b        The second value to test.
 151 @result         true if the two values are strict equal, otherwise false.
 152 */
 153 JS_EXPORT bool JSValueIsStrictEqual(JSContextRef ctx, JSValueRef a, JSValueRef b);
 154
 155 /*!
 156 @function
 157 @abstract Tests whether a JavaScript value is an object constructed by a given constructor, as compared by the JS instanceof operator.
 158 @param ctx The execution context to use.
 159 @param value The JSValue to test.
 160 @param constructor The constructor to test against.
 161 @param exception A pointer to a JSValueRef in which to store an exception, if any. Pass NULL if you do not care to store an exception.
 162 @result true if value is an object constructed by constructor, as compared by the JS instanceof operator, otherwise false.
 163 */
 164 JS_EXPORT bool JSValueIsInstanceOfConstructor(JSContextRef ctx, JSValueRef value, JSObjectRef constructor, JSValueRef* exception);
 165
 166 /* Creating values */
 167
 168 /*!
 169 @function
 170 @abstract       Creates a JavaScript value of the undefined type.
 171 @param ctx  The execution context to use.
 172 @result         The unique undefined value.
 173 */
 174 JS_EXPORT JSValueRef JSValueMakeUndefined(JSContextRef ctx);
 175
 176 /*!
 177 @function
 178 @abstract       Creates a JavaScript value of the null type.
 179 @param ctx  The execution context to use.
 180 @result         The unique null value.
 181 */
 182 JS_EXPORT JSValueRef JSValueMakeNull(JSContextRef ctx);
 183
 184 /*!
 185 @function
 186 @abstract       Creates a JavaScript value of the boolean type.
 187 @param ctx  The execution context to use.
 188 @param boolean  The bool to assign to the newly created JSValue.
 189 @result         A JSValue of the boolean type, representing the value of boolean.
 190 */
 191 JS_EXPORT JSValueRef JSValueMakeBoolean(JSContextRef ctx, bool boolean);
 192
 193 /*!
 194 @function
 195 @abstract       Creates a JavaScript value of the number type.
 196 @param ctx  The execution context to use.
 197 @param number   The double to assign to the newly created JSValue.
 198 @result         A JSValue of the number type, representing the value of number.
 199 */
 200 JS_EXPORT JSValueRef JSValueMakeNumber(JSContextRef ctx, double number);
 201
 202 /*!
 203 @function
 204 @abstract       Creates a JavaScript value of the string type.
 205 @param ctx  The execution context to use.
 206 @param string   The JSString to assign to the newly created JSValue. The
 207  newly created JSValue retains string, and releases it upon garbage collection.
 208 @result         A JSValue of the string type, representing the value of string.
 209 */
 210 JS_EXPORT JSValueRef JSValueMakeString(JSContextRef ctx, JSStringRef string);
 211
 212 /* Converting to and from JSON formatted strings */
 213
 214 /*!
 215  @function
 216  @abstract       Creates a JavaScript value from a JSON formatted string.
 217  @param ctx      The execution context to use.
 218  @param string   The JSString containing the JSON string to be parsed.
 219  @result         A JSValue containing the parsed value, or NULL if the input is invalid.
 220  */
 221 JS_EXPORT JSValueRef JSValueMakeFromJSONString(JSContextRef ctx, JSStringRef string) AVAILABLE_AFTER_WEBKIT_VERSION_4_0;
 222
 223 /*!
 224  @function
 225  @abstract       Creates a JavaScript string containing the JSON serialized representation of a JS value.
 226  @param ctx      The execution context to use.
 227  @param value    The value to serialize.
 228  @param indent   The number of spaces to indent when nesting.  If 0, the resulting JSON will not contains newlines.  The size of the indent is clamped to 10 spaces.
 229  @param exception A pointer to a JSValueRef in which to store an exception, if any. Pass NULL if you do not care to store an exception.
 230  @result         A JSString with the result of serialization, or NULL if an exception is thrown.
 231  */
 232 JS_EXPORT JSStringRef JSValueCreateJSONString(JSContextRef ctx, JSValueRef value, unsigned indent, JSValueRef* exception) AVAILABLE_AFTER_WEBKIT_VERSION_4_0;
 233
 234 /* Converting to primitive values */
 235
 236 /*!
 237 @function
 238 @abstract       Converts a JavaScript value to boolean and returns the resulting boolean.
 239 @param ctx  The execution context to use.
 240 @param value    The JSValue to convert.
 241 @result         The boolean result of conversion.
 242 */
 243 JS_EXPORT bool JSValueToBoolean(JSContextRef ctx, JSValueRef value);
 244
 245 /*!
 246 @function
 247 @abstract       Converts a JavaScript value to number and returns the resulting number.
 248 @param ctx  The execution context to use.
 249 @param value    The JSValue to convert.
 250 @param exception A pointer to a JSValueRef in which to store an exception, if any. Pass NULL if you do not care to store an exception.
 251 @result         The numeric result of conversion, or NaN if an exception is thrown.
 252 */
 253 JS_EXPORT double JSValueToNumber(JSContextRef ctx, JSValueRef value, JSValueRef* exception);
 254
 255 /*!
 256 @function
 257 @abstract       Converts a JavaScript value to string and copies the result into a JavaScript string.
 258 @param ctx  The execution context to use.
 259 @param value    The JSValue to convert.
 260 @param exception A pointer to a JSValueRef in which to store an exception, if any. Pass NULL if you do not care to store an exception.
 261 @result         A JSString with the result of conversion, or NULL if an exception is thrown. Ownership follows the Create Rule.
 262 */
 263 JS_EXPORT JSStringRef JSValueToStringCopy(JSContextRef ctx, JSValueRef value, JSValueRef* exception);
 264
 265 /*!
 266 @function
 267 @abstract Converts a JavaScript value to object and returns the resulting object.
 268 @param ctx  The execution context to use.
 269 @param value    The JSValue to convert.
 270 @param exception A pointer to a JSValueRef in which to store an exception, if any. Pass NULL if you do not care to store an exception.
 271 @result         The JSObject result of conversion, or NULL if an exception is thrown.
 272 */
 273 JS_EXPORT JSObjectRef JSValueToObject(JSContextRef ctx, JSValueRef value, JSValueRef* exception);
 274
 275 /* Garbage collection */
 276 /*!
 277 @function
 278 @abstract Protects a JavaScript value from garbage collection.
 279 @param ctx The execution context to use.
 280 @param value The JSValue to protect.
 281 @discussion Use this method when you want to store a JSValue in a global or on the heap, where the garbage collector will not be able to discover your reference to it.
 282
 283 A value may be protected multiple times and must be unprotected an equal number of times before becoming eligible for garbage collection.
 284 */
 285 JS_EXPORT void JSValueProtect(JSContextRef ctx, JSValueRef value);
 286
 287 /*!
 288 @function
 289 @abstract       Unprotects a JavaScript value from garbage collection.
 290 @param ctx      The execution context to use.
 291 @param value    The JSValue to unprotect.
 292 @discussion     A value may be protected multiple times and must be unprotected an
 293  equal number of times before becoming eligible for garbage collection.
 294 */
 295 JS_EXPORT void JSValueUnprotect(JSContextRef ctx, JSValueRef value);
 296
 297 #ifdef __cplusplus
 298 }
 299 #endif
 300
 301 #endif /* JSValueRef_h */