Add support for JavaScript Array in binding layer

[yichoi]

• Add array support in binding layer
  • create array / check if object is array / ...
  • add support to easily iterate over array elements (esp. for sparse array, maybe in jerry?)
  • ... (TBD)
• Use array support in IoT.js
  • in i2c module, many APIs should use array as input parameter or callback argument
  • in buffer module, enable new Buffer(array)
  • in http_incoming module, IncomingMessage.headers should be array type
  • ... (TBD)

[nova0821]

I think it will be better to support more APIs in binding layer. For example, push(add) and pop(remove) for numbered index and named index will be very helpful.

[glistening]

I made a PR for array creating and checking for char array. Please see #460.

[RedCarrottt]

Is there any progress in this issue? If anyone did not made a progress, I want to handle it.

[glistening]

We intentionally don't put more time into this issue since we don't want to make APIs bigger. We want to keep APIs minimal.

[glistening]

All the issues posted are in progress or in pending for some reason. Therefore I recommend you suggest your proposal in issue. You can refer to the guide in Development-Process, especially in Feature development process.

[glistening]

buffer module, enable new Buffer(array) - done
in http_incoming module, IncomingMessage.headers should be array type - landed in #776
add support to easily iterate over array elements - We want to keep the API minimal. Let's discuss this item when we need this API.

[akhilkedia]

@glistening Right now, there is no support to easily iterate over JS array elements on the C side.
This feature will be extremely useful in a OCF Things SDK I am currently working on.
Is support for this planned in the near future, or will it not be supported to keep APIs minimal?

Note - While it would be great to have support in binding for Array Iteration, there are some workarounds which can be used right now. Currently I convert the array to object on the JS side, pass the object to C side, iterate over the elements of the object and create a new array on the C side.
For example, this Array -
['a','b','c']
Becomes -
{ 0: 'a', 1: 'b', 2: 'c' }

[LaszloLango]

@akhilkedia you can call jerry_get_array_length and jerry_get_property_by_index directly until the IoT.js binding hasn't done.