Add json parse and stringify function to jerryscript c api

JerryScript-DCO-1.0-Signed-off-by: Zsolt Raduska [email protected]

Author: ZsoltRaduska

docs/02.API-REFERENCE.md

@@ -5561,3 +5561,67 @@ jerry_value_t jerry_get_typedarray_buffer (jerry_value_t value,
 **See also**
 
 - [jerry_create_typedarray](#jerry_create_typedarray)
+
+# JSON functions
+
+## jerry_json_parse
+
+**Summary**
+
+Parse a JSON string.
+Returns a jerry_value_t which contains key-value pairs imported from the JSON string.
+
+**Prototype**
+
+```c
+jerry_value_t jerry_json_parse (const char *json_string)
+```
+
+- `json_string` - a JSON formated string to parse
+
+**Example**
+
+```c
+{
+  const char *data_in_json = "{\"name\": \"John\", \"age\": 5}";
+  jerry_value_t parsed_json = jerry_json_parse (data_in_json);
+
+  // parsed_json now conatins all of data stored in data_in_json
+
+  jerry_release_value (parsed_json);
+}
+```
+
+## jerry_stringify
+
+  **Summary**
+
+  Stringify a jerry_value_t object.
+  Convert a jerry_value_t object into a json formated string.
+
+  **Prototype**
+
+```c
+jerry_value_t jerry_json_stringfy (const jerry_value_t object_to_stringify)
+```
+
+- `object_to_stringify` - a jerry_value_t object to stringify
+
+**Example**
+
+```c
+{
+  jerry_value_t obj = jerry_create_object ();
+  jerry_value_t key = jerry_create_string ((const jerry_char_t *) "name");
+  jerry_value_t value = jerry_create_string ((const jerry_char_t *) "John");
+  jerry_set_property (obj, key, value);
+  jerry_value_t stringified = jerry_json_stringfy (obj);
+
+  //stringified now contains a json formated string
+
+  jerry_release_value (obj);
+  jerry_release_value (key);
+  jerry_release_value (value);
+  jerry_release_value (stringified);
+}
+```

jerry-core/api/jerry.c

@@ -3334,6 +3334,63 @@ jerry_get_typedarray_buffer (jerry_value_t value, /**< TypedArray to get the arr
 #endif /* !CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN */
 } /* jerry_get_typedarray_buffer */
 
+/**
+ * Create an object from JSON
+ *
+ * Note:
+ *      The returned value must be freed with jerry_release_value
+ * @return jerry_value_t from json formated string
+ */
+jerry_value_t
+jerry_json_parse (const char *json_string)
+{
+  jerry_assert_api_available ();
+
+#ifndef CONFIG_DISABLE_JSON_BUILTIN
+  lit_utf8_size_t json_string_size = lit_zt_utf8_string_size ((lit_utf8_byte_t *) json_string);
+  const lit_utf8_byte_t *json_string_p = (const lit_utf8_byte_t *) (json_string);
+  ecma_value_t ret_value = ecma_builtin_json_fill_token_fields_from_string (json_string_p, json_string_size);
+
+  if (ecma_is_value_undefined (ret_value))
+  {
+    ret_value = jerry_throw (ecma_raise_syntax_error (ECMA_ERR_MSG ("JSON string parse error.")));
+  }
+
+  return ret_value;
+#else /* CONFIG_DISABLE_JSON_BUILTIN */
+  JERRY_UNUSED (json_string);
+
+  return jerry_throw (ecma_raise_syntax_error (ECMA_ERR_MSG ("The JSON has been disabled.")));
+#endif /* !CONFIG_DISABLE_JSON_BUILTIN */
+} /* jerry_json_parse */
+
+/**
+ * Create a Json formated string from an object
+ *
+ * Note:
+ *      The returned value must be freed with jerry_release_value
+ * @return json formated jerry_value_t
+ */
+jerry_value_t
+jerry_json_stringfy (const jerry_value_t object_to_stringify)
+{
+  jerry_assert_api_available ();
+#ifndef CONFIG_DISABLE_JSON_BUILTIN
+  ecma_value_t ret_value = ecma_builtin_json_string_from_object (object_to_stringify);
+
+  if (ecma_is_value_undefined (ret_value))
+  {
+    ret_value = jerry_throw (ecma_raise_syntax_error (ECMA_ERR_MSG ("JSON stringify error.")));
+  }
+
+  return ret_value;
+#else /* CONFIG_DISABLE_JSON_BUILTIN */
+  JERRY_UNUSED (object_to_stringify);
+
+  return jerry_throw (ecma_raise_syntax_error (ECMA_ERR_MSG ("The JSON has been disabled.")));
+#endif /* !CONFIG_DISABLE_JSON_BUILTIN */
+} /* jerry_json_stringfy */
+
 /**
  * @}
  */

jerry-core/ecma/builtin-objects/ecma-builtin-helpers-json.c

@@ -17,6 +17,10 @@
 #include "ecma-helpers.h"
 #include "ecma-builtin-helpers.h"
 #include "lit-char-helpers.h"
+#include "ecma-try-catch-macro.h"
+#include "ecma-objects.h"
+
+#ifndef CONFIG_DISABLE_JSON_BUILTIN
 
 /** \addtogroup ecma ECMA
  * @{
@@ -221,6 +225,91 @@ ecma_builtin_helper_json_create_non_formatted_json (lit_utf8_byte_t left_bracket
   return ecma_make_string_value (result_str_p);
 } /* ecma_builtin_helper_json_create_non_formatted_json */
 
+/**
+ * Function to set a string token from the given arguments, fill its fields and advances the string pointer.
+ *
+ * @return ecma value
+ *         Returned value must be freed with ecma_free_value.
+ */
+ecma_value_t
+ecma_builtin_json_fill_token_fields_from_string (const lit_utf8_byte_t * str_start_p, lit_utf8_size_t string_size)
+{
+  ecma_json_token_t token;
+  token.current_p = str_start_p;
+  token.end_p = str_start_p + string_size;
+
+  ecma_value_t final_result = ecma_builtin_json_parse_value (&token);
+
+  if (!ecma_is_value_undefined (final_result))
+  {
+    ecma_builtin_json_parse_next_token (&token, false);
+
+    if (token.type != end_token)
+    {
+      ecma_free_value (final_result);
+      final_result = ECMA_VALUE_UNDEFINED;
+    }
+  }
+  return final_result;
+} /*ecma_builtin_json_fill_token_fields_from_string*/
+
+/**
+ * Helper functions to stringify an object in JSON format representing an ecma_value.
+ *
+ *  @return ecma value
+ *          Returned value must be freed with ecma_free_value.
+ *
+ */
+ecma_value_t ema_builtin_json_str_helper (const ecma_value_t arg1, ecma_json_stringify_context_t context)
+{
+  ecma_value_t ret_value = ECMA_VALUE_EMPTY;
+  ecma_object_t *obj_wrapper_p = ecma_op_create_object_object_noarg ();
+  ecma_string_t *empty_str_p = ecma_get_magic_string (LIT_MAGIC_STRING__EMPTY);
+  ecma_value_t put_comp_val = ecma_op_object_put (obj_wrapper_p,
+                                                  empty_str_p,
+                                                  arg1,
+                                                  false);
+  JERRY_ASSERT (ecma_is_value_true (put_comp_val));
+  ecma_free_value (put_comp_val);
+  ECMA_TRY_CATCH (str_val,
+                  ecma_builtin_json_str (empty_str_p, obj_wrapper_p, &context),
+                  ret_value);
+  ret_value = ecma_copy_value (str_val);
+  ECMA_FINALIZE (str_val);
+  ecma_free_value (put_comp_val);
+  ecma_deref_ecma_string (empty_str_p);
+  ecma_deref_object (obj_wrapper_p);
+
+  return ret_value;
+} /* ema_builtin_json_str_helper */
+
+/**
+ * Function to create a json formated string from an object
+ *
+ * @return ecma value
+ *         Returned value must be freed with ecma_free_value.
+ */
+ecma_value_t
+ecma_builtin_json_string_from_object (const ecma_value_t arg1)
+{
+  ecma_value_t ret_value = ECMA_VALUE_EMPTY;
+  ecma_json_stringify_context_t context;
+  context.occurence_stack_last_p = NULL;
+  context.indent_str_p = ecma_get_magic_string (LIT_MAGIC_STRING__EMPTY);
+  context.property_list_p = ecma_new_values_collection ();
+  context.replacer_function_p = NULL;
+  context.gap_str_p = ecma_get_magic_string (LIT_MAGIC_STRING__EMPTY);
+
+  ret_value = ema_builtin_json_str_helper (arg1, context);
+
+  ecma_deref_ecma_string (context.gap_str_p);
+  ecma_deref_ecma_string (context.indent_str_p);
+  ecma_free_values_collection (context.property_list_p, 0);
+  return ret_value;
+} /*ecma_builtin_json_string_from_object*/
+
+#endif /* !CONFIG_DISABLE_JSON_BUILTIN */
+
 /**
  * @}
  * @}

jerry-core/ecma/builtin-objects/ecma-builtin-helpers.h

@@ -131,6 +131,44 @@ typedef struct struct_ecma_json_occurence_stack_item_t
   ecma_object_t *object_p; /**< current object */
 } ecma_json_occurence_stack_item_t;
 
+/**
+ * JSON token type
+ */
+typedef enum
+{
+  invalid_token, /**< error token */
+  end_token, /**< end of stream reached */
+  number_token, /**< JSON number */
+  string_token, /**< JSON string */
+  null_token, /**< JSON null primitive value */
+  true_token, /**< JSON true primitive value */
+  false_token, /**< JSON false primitive value */
+  left_brace_token, /**< JSON left brace */
+  right_brace_token, /**< JSON right brace */
+  left_square_token, /**< JSON left square bracket */
+  comma_token, /**< JSON comma */
+  colon_token /**< JSON colon */
+} ecma_json_token_type_t;
+
+/**
+ * JSON token
+ */
+typedef struct
+{
+  ecma_json_token_type_t type; /**< type of the current token */
+  const lit_utf8_byte_t *current_p; /**< current position of the string processed by the parser */
+  const lit_utf8_byte_t *end_p; /**< end of the string processed by the parser */
+
+  /**
+   * Fields depending on type.
+   */
+  union
+  {
+    ecma_string_t *string_p; /**< when type is string_token it contains the string */
+    ecma_number_t number; /**< when type is number_token, it contains the value of the number */
+  } u;
+} ecma_json_token_t;
+
 /**
  * Context for JSON.stringify()
  */
@@ -152,6 +190,26 @@ typedef struct
   ecma_object_t *replacer_function_p;
 } ecma_json_stringify_context_t;
 
+ecma_value_t ecma_builtin_json_parse_value (ecma_json_token_t *token_p);
+void ecma_builtin_json_parse_next_token (ecma_json_token_t *token_p, /**< token argument */
+                                    bool parse_string); /**< strings are allowed to parse */
+ecma_object_t *ecma_op_create_object_object_noarg (void);
+ecma_value_t
+ecma_op_object_put (ecma_object_t *object_p, /**< the object */
+                    ecma_string_t *property_name_p, /**< property name */
+                    ecma_value_t value, /**< ecma value */
+                    bool is_throw); /**< flag that controls failure handling */
+ecma_value_t
+ecma_builtin_json_str (ecma_string_t *key_p, /**< property key*/
+                       ecma_object_t *holder_p, /**< the object*/
+                       ecma_json_stringify_context_t *context_p) ;/**< context*/
+ecma_value_t ecma_builtin_json_fill_token_fields_from_string (const lit_utf8_byte_t * str_start_p,
+                                                              lit_utf8_size_t string_size);
+void ecma_deref_object (ecma_object_t *object_p);
+bool
+ecma_op_is_callable (ecma_value_t value);
+ecma_value_t ecma_builtin_json_string_from_object (const ecma_value_t arg1);
+ecma_value_t ema_builtin_json_str_helper (const ecma_value_t arg1, ecma_json_stringify_context_t context);
 bool ecma_json_has_object_in_stack (ecma_json_occurence_stack_item_t *stack_p, ecma_object_t *object_p);
 bool ecma_has_string_value_in_collection (ecma_collection_header_t *collection_p, ecma_value_t string_value);