add transform_object_properties in jerryx/arg (#1879)

Add a function in jerryx/arg.
jerryx_arg_transform_object_properties, it will validate the properties of a JS object, and convert those properties into native type.

JerryScript-DCO-1.0-Signed-off-by: Zidong Jiang zidong.jiang@intel.com

jerry-ext/arg/arg-transform-functions.c

@@ -63,7 +63,7 @@ jerryx_arg_transform_number_strict (jerryx_arg_js_iterator_t *js_arg_iter_p, /**
 } /* jerryx_arg_transform_number_strict */
 
 /**
- * Tranform a JS argument to a double. Type coercion is allowed.
+ * Transform a JS argument to a double. Type coercion is allowed.
  *
  * @return jerry undefined: the transformer passes,
  *         jerry error: the transformer fails.
@@ -251,7 +251,7 @@ jerryx_arg_transform_native_pointer (jerryx_arg_js_iterator_t *js_arg_iter_p, /*
   if (!jerry_value_is_object (js_arg))
   {
     return jerry_create_error (JERRY_ERROR_TYPE,
-                               (jerry_char_t *) "It is not a object.");
+                               (jerry_char_t *) "It is not an object.");
   }
 
   const jerry_object_native_info_t *expected_info_p;
@@ -269,6 +269,27 @@ jerryx_arg_transform_native_pointer (jerryx_arg_js_iterator_t *js_arg_iter_p, /*
   return jerry_create_undefined ();
 } /* jerryx_arg_transform_native_pointer */
 
+/**
+ * Check whether the JS object's properties have expected types, and transform them into native args.
+ *
+ * @return jerry undefined: the transformer passes,
+ *         jerry error: the transformer fails.
+ */
+jerry_value_t
+jerryx_arg_transform_object_props (jerryx_arg_js_iterator_t *js_arg_iter_p, /**< available JS args */
+                                   const jerryx_arg_t *c_arg_p) /**< the native arg */
+{
+  jerry_value_t js_arg = jerryx_arg_js_iterator_pop (js_arg_iter_p);
+
+  const jerryx_arg_object_props_t *object_props = (const jerryx_arg_object_props_t *) c_arg_p->extra_info;
+
+  return jerryx_arg_transform_object_properties (js_arg,
+                                                 object_props->name_p,
+                                                 object_props->name_cnt,
+                                                 object_props->c_arg_p,
+                                                 object_props->c_arg_cnt);
+} /* jerryx_arg_transform_object_props */
+
 /**
  * Define transformer for optional argument.
  */
@@ -288,6 +309,7 @@ JERRYX_ARG_TRANSFORM_OPTIONAL (string)
 JERRYX_ARG_TRANSFORM_OPTIONAL (string_strict)
 JERRYX_ARG_TRANSFORM_OPTIONAL (function)
 JERRYX_ARG_TRANSFORM_OPTIONAL (native_pointer)
+JERRYX_ARG_TRANSFORM_OPTIONAL (object_props)
 
 /**
  * Ignore the JS argument.

jerry-ext/arg/arg.c

@@ -81,8 +81,56 @@ jerryx_arg_transform_this_and_args (const jerry_value_t this_val, /**< the this_
   {
     jerry_release_value (ret);
 
-    return jerry_create_error (JERRY_ERROR_TYPE, (jerry_char_t *) "'this' validation failed");
+    return jerry_create_error (JERRY_ERROR_TYPE, (jerry_char_t *) "'this' validation failed.");
   }
 
   return jerryx_arg_transform_args (js_arg_p, js_arg_cnt, c_arg_p + 1, c_arg_cnt - 1);
 } /* jerryx_arg_transform_this_and_args */
+
+/**
+ * Validate the `obj_val`'s properties,
+ * and assign them to the native arguments.
+ *
+ * @return jerry undefined: all validators passed,
+ *         jerry error: a validator failed.
+ */
+jerry_value_t
+jerryx_arg_transform_object_properties (const jerry_value_t obj_val,/**< the JS object */
+                                        const jerry_char_t **name_p, /**< property name list of the JS object */
+                                        const jerry_length_t name_cnt, /**< count of the name list */
+                                        const jerryx_arg_t *c_arg_p, /**< points to the array of transformation steps */
+                                        jerry_length_t c_arg_cnt) /**< the count of the `c_arg_p` array */
+{
+  if (!jerry_value_is_object (obj_val))
+  {
+    return jerry_create_error (JERRY_ERROR_TYPE, (jerry_char_t *) "Not an object.");
+  }
+
+  jerry_value_t prop[name_cnt];
+
+  for (jerry_length_t i = 0; i < name_cnt; i++, name_p++)
+  {
+    const jerry_value_t name_str = jerry_create_string (*name_p);
+    prop[i] = jerry_get_property (obj_val, name_str);
+    jerry_release_value (name_str);
+
+    if (jerry_value_has_error_flag (prop[i]))
+    {
+      for (jerry_length_t j = 0; j < i; j++)
+      {
+        jerry_release_value (prop[j]);
+      }
+
+      return prop[i];
+    }
+  }
+
+  const jerry_value_t ret = jerryx_arg_transform_args (prop, name_cnt, c_arg_p, c_arg_cnt);
+
+  for (jerry_length_t i = 0; i < name_cnt; i++)
+  {
+    jerry_release_value (prop[i]);
+  }
+
+  return ret;
+} /* jerryx_arg_transform_object_properties */