Update the webpage

JerryScript-DCO-1.0-Signed-off-by: Zsolt Borbély zsborbely.u-szeged@partner.samsung.com
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Zsolt Borbély 2017-11-29 15:20:06 +01:00 committed by yichoi
parent 196c4cb17e
commit 4e6dc2f538
3 changed files with 186 additions and 1 deletions

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@ -561,6 +561,50 @@ Value of x is 12
Value of x is 17
```
## Step 8. Changing the seed of pseudorandom generated numbers
If you want to change the seed of `Math.random()` generated numbers, you have to initialize the seed value with `srand`.
A recommended method is using `jerry_port_get_current_time()` or something based on a constantly changing value, therefore every run produces truly random numbers.
[doctest]: # ()
```c
#include <string.h>
#include <stdlib.h>
#include "jerryscript.h"
#include "jerryscript-port.h"
#include "jerryscript-ext/handler.h"
int
main (void)
{
/* Initialize srand value */
srand ((unsigned) jerry_port_get_current_time ());
/* Generate a random number, and print it */
const jerry_char_t script[] = "var a = Math.random (); print(a)";
size_t script_size = strlen ((const char *) script);
/* Initialize the engine */
jerry_init (JERRY_INIT_EMPTY);
/* Register the print function */
jerryx_handler_register_global ((const jerry_char_t *) "print",
jerryx_handler_print);
/* Evaluate the script */
jerry_value_t eval_ret = jerry_eval (script, script_size, false);
/* Free the JavaScript value returned by eval */
jerry_release_value (eval_ret);
/* Cleanup the engine */
jerry_cleanup ();
return 0;
}
```
## Further steps
For further API description, please visit [API Reference page](https://jerryscript-project.github.io/jerryscript/api-reference/) on [JerryScript home page](https://jerryscript-project.github.io/jerryscript/).

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@ -115,7 +115,7 @@ Allow user to provide external buffer for jerry instance (which includes an isol
*
*Note:
* This port function will be called automatically by jerry-core
* wnen JERRY_ENABLE_EXTERNAL_CONTEXT is defined. If not, this function will never be called.
* when JERRY_ENABLE_EXTERNAL_CONTEXT is defined. If not, this function will never be called.
*
* @return the pointer to the jerry instance.
*/

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@ -66,6 +66,27 @@ typedef struct
- [jerryx_arg_object_properties](#jerryx_arg_object_properties)
## jerryx_arg_array_items_t
**Summary**
The structure is used in `jerryx_arg_array`. It provides the array items' corresponding
JS-to-C mappings and count.
**Prototype**
```c
typedef struct
{
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 */
} jerryx_arg_array_items_t;
```
**See also**
- [jerryx_arg_array](#jerryx_arg_array)
## jerryx_arg_transform_func_t
**Summary**
@ -320,6 +341,35 @@ jerryx_arg_transform_object_properties (const jerry_value_t obj_val,
- [jerryx_arg_object_properties](#jerryx_arg_object_properties)
## jerryx_arg_transform_array
**Summary**
Validate the JS array and assign its items to the native arguments.
*Note*: This function transforms items of a single JS array into native C values.
To transform multiple JS arguments in one pass, please use `jerryx_arg_array` together with
`jerryx_arg_transform_this_and_args` or `jerryx_arg_transform_args`.
**Prototype**
```c
jerry_value_t
jerryx_arg_transform_array (const jerry_value_t array_val,
const jerryx_arg_t *c_arg_p,
jerry_length_t c_arg_cnt);
```
- `array_val` - the JS array.
- `c_arg_p` - points to the array of validation/transformation steps
- `c_arg_cnt` - the count of the `c_arg_p` array.
- return value - a `jerry_value_t` representing `undefined` if all validators passed or an `Error` if a validator failed.
**See also**
- [jerryx_arg_array](#jerryx_arg_array)
# Helpers for commonly used validations
@ -590,6 +640,97 @@ my_external_handler (const jerry_value_t function_obj,
- [jerryx_arg_transform_this_and_args](#jerryx_arg_transform_this_and_args)
- [jerryx_arg_transform_object_properties](#jerryx_arg_transform_object_properties)
## jerryx_arg_array
**Summary**
Create a validation/transformation step (`jerryx_arg_t`) that expects to
consume one `array` JS argument and call `jerryx_arg_transform_array_items` inside
to transform its items to native arguments.
User should prepare the `jerryx_arg_array_items_t` instance, and pass it to this function.
**Prototype**
```c
static inline jerryx_arg_t
jerryx_arg_array (const jerryx_arg_array_items_t *array_items_p, jerryx_arg_optional_t opt_flag);
```
- return value - the created `jerryx_arg_t` instance.
- `array_items_p` - provides items information for transform.
- `opt_flag` - whether the argument is optional.
**Example**
[doctest]: # (test="compile")
```c
#include "jerryscript.h"
#include "jerryscript-ext/arg.h"
/**
* The binding function expects args_p[0] is an array, which has 3 items:
* first: boolean
* second: number
* third: number, optional
*/
static jerry_value_t
my_external_handler (const jerry_value_t function_obj,
const jerry_value_t this_val,
const jerry_value_t args_p[],
const jerry_length_t args_count)
{
bool required_bool;
double required_num;
double optional_num = 1234.567; // default value
/* "item_mapping" defines the steps to transform array items to C variables. */
const jerryx_arg_t item_mapping[] =
{
jerryx_arg_boolean (&required_bool, JERRYX_ARG_COERCE, JERRYX_ARG_REQUIRED),
jerryx_arg_number (&required_num, JERRYX_ARG_COERCE, JERRYX_ARG_REQUIRED),
jerryx_arg_number (&optional_num, JERRYX_ARG_COERCE, JERRYX_ARG_OPTIONAL)
};
/* Prepare the jerryx_arg_array_items_t instance. */
const jerryx_arg_array_items_t array_info =
{
.c_arg_p = item_mapping,
.c_arg_cnt = 3
};
/* It is the mapping used in the jerryx_arg_transform_args. */
const jerryx_arg_t mapping[] =
{
jerryx_arg_array (&array_info, JERRYX_ARG_REQUIRED)
};
/* Validate and transform. */
const jerry_value_t rv = jerryx_arg_transform_args (args_p,
args_count,
mapping,
1);
if (jerry_value_has_error_flag (rv))
{
/* Handle error. */
return rv;
}
/*
* Validated and transformed successfully!
* required_bool, required_num and optional_num can now be used.
*/
return jerry_create_undefined (); /* Or return something more meaningful. */
}
```
**See also**
- [jerryx_arg_transform_this_and_args](#jerryx_arg_transform_this_and_args)
- [jerryx_arg_transform_object_properties](#jerryx_arg_transform_object_properties)
# Functions to create custom validations
## jerryx_arg_custom