# Addon Tools


## Synopsis

This is a set of helpers for simplification and standardization of addons and
dependency packages.

* EventEmitter C++ implementation.
* Contains helpers of following types: GYP, C++, JS, BAT (Windows).
* Platforms: win x32/x64, linux x32/x64, mac x64.
* Useful links: [V8 Ref](https://v8docs.nodesource.com/node-0.8/d2/dc3/namespacev8.html),
[Nan Docs](https://github.com/nodejs/nan#api),
[GYP Docs](https://gyp.gsrc.io/docs/UserDocumentation.md).


## Install

`npm i -s addon-tools-raub`


---

## Contents

[Snippets](#snippets)

[include/addon-tools.hpp](#includeaddon-toolshpp)

[index.js](#indexjs)

[Cross-platform commands](#cross-platform-commands)

[Class EventEmitter](#class-eventemitter)

---


## Snippets

### binding.gyp

* Cross-platform file/folder removers/creators are present, you can put them into variables for later use.

```
'variables': {
	'rm'    : '<!(node -e "require(\'addon-tools-raub\').rm()")',
	'cp'    : '<!(node -e "require(\'addon-tools-raub\').cp()")',
	'mkdir' : '<!(node -e "require(\'addon-tools-raub\').mkdir()")',
},
```

* Include directories for Addon Tools and Nan (which is preinstalled with Addon Tools)
are accessible as shown below.

```
	'include_dirs': [
		'<!@(node -e "require(\'addon-tools-raub\').include()")',
	],
```

* Intermediate files can be removed in a separate build-step with `<(rm)`.

```
	[ 'OS=="linux"', { 'action' : [
		'<(rm)',
		'<(module_root_dir)/build/Release/obj.target/addon/cpp/addon.o',
		'<(module_root_dir)/build/Release/addon.node'
	] } ],
	[ 'OS=="mac"', { 'action' : [
		'<(rm)',
		'<(module_root_dir)/build/Release/obj.target/addon/cpp/addon.o',
		'<(module_root_dir)/build/Release/addon.node'
	] } ],
	[ 'OS=="win"', { 'action' : [
		'<(rm)',
		'<(module_root_dir)/build/Release/addon.*',
		'<(module_root_dir)/build/Release/obj/addon/*.*'
	] } ],
```


### Binary dependencies

If you design a module with binary dependencies for several platforms, Addon Tools
would encourage you to abide by the following rules:

* Your binary directories are:
	* bin-win32
	* bin-win64
	* bin-linux32
	* bin-linux64
	* bin-mac64

* The following piece of code in your `index.js` without changes. Method `paths()`
is described [here](#indexjs).

```
module.exports = require('addon-tools-raub').paths(__dirname);
```

* Your whole `binding.gyp`:

```
{
	'variables': {
		'rm'  : '<!(node -e "require(\'addon-tools-raub\').rm()")',
		'rem' : '<!(node -e "require(\'.\').rem()")',
	},
	'targets': [
		{
			'target_name' : 'remove_extras',
			'type'        : 'none',
			'actions'     : [
				{
					'action_name' : 'Unnecessary binaries removed.',
					'inputs'      : [],
					'outputs'     : ['build'],
					'action'      : ['<(rm)', '-rf', '<@(rem)'],
				}
			],
		}
	]
}

```



### Compiled addon

If you always copy your compiled addon to the `binary` directory, it will be easy to
`require()` it without any hesitation. For copying, you can use the following snippet:

```
{
	'target_name'  : 'make_directory',
	'type'         : 'none',
	'dependencies' : ['MY_ADDON'],
	'actions'      : [{
		'action_name' : 'Directory created.',
		'inputs'      : [],
		'outputs'     : ['build'],
		'action': ['<(mkdir)', '-p', 'binary']
	}],
},
{
	'target_name'  : 'copy_binary',
	'type'         : 'none',
	'dependencies' : ['make_directory'],
	'actions'      : [{
		'action_name' : 'Module copied.',
		'inputs'      : [],
		'outputs'     : ['binary'],
		'action'      : ['<(cp)', 'build/Release/MY_ADDON.node', 'binary/MY_ADDON.node'],
	}],
},
```

Here `MY_ADDON` should be replaced by any name you like. Then require like
this:

```
module.exports = require('./binary/MY_ADDON');
```

#### Generic addon snippet

<details>

<summary>binding.gyp</summary>

* Assume `EXT_LIB` is the name of an Addon Tools compliant binary dependency module.
* Assume `MY_ADDON` is the name of this addon.
* Assume C++ code goes to `cpp` directory.

```
{
	'variables': {
		'rm'              : '<!(node -e "require(\'addon-tools-raub\').rm()")',
		'cp'              : '<!(node -e "require(\'addon-tools-raub\').cp()")',
		'mkdir'           : '<!(node -e "require(\'addon-tools-raub\').mkdir()")',
		'EXT_LIB_include' : '<!(node -e "require(\'node-deps-EXT_LIB-raub\').include()")',
		'EXT_LIB_bin'     : '<!(node -e "require(\'node-deps-EXT_LIB-raub\').bin()")',
	},
	'targets': [
		{
			'target_name': 'MY_ADDON',
			'sources': [
				'cpp/MY_ADDON.cpp',
			],
			'include_dirs': [
				'<!(node -e "require(\'addon-tools-raub\').include()")',
				'<(EXT_LIB_include)',
				'<(module_root_dir)/include',
			],
			'library_dirs': [ '<(EXT_LIB_bin)' ],
			'conditions': [
				[
					'OS=="linux"',
					{
						'libraries': [
							'-Wl,-rpath,<(EXT_LIB_bin)',
							'<(EXT_LIB_bin)/libEXT_LIB.so',
						],
					}
				],
				[
					'OS=="mac"',
					{
						'libraries': [
							'-Wl,-rpath,<(EXT_LIB_bin)',
							'<(EXT_LIB_bin)/EXT_LIB.dylib',
						],
					}
				],
				[
					'OS=="win"',
					{
						'libraries': [ 'EXT_LIB.lib' ],
						'defines' : [
							'WIN32_LEAN_AND_MEAN',
							'VC_EXTRALEAN'
						],
						'msvs_version'  : '2013',
						'msvs_settings' : {
							'VCCLCompilerTool' : {
								'AdditionalOptions' : [
									'/O2','/Oy','/GL','/GF','/Gm-','/EHsc',
									'/MT','/GS','/Gy','/GR-','/Gd',
								]
							},
							'VCLinkerTool' : {
								'AdditionalOptions' : ['/OPT:REF','/OPT:ICF','/LTCG']
							},
						},
					}
				],
			],
		},
		
		{
			'target_name'  : 'make_directory',
			'type'         : 'none',
			'dependencies' : ['MY_ADDON'],
			'actions'      : [{
				'action_name' : 'Directory created.',
				'inputs'      : [],
				'outputs'     : ['build'],
				'action': ['<(mkdir)', '-p', 'binary']
			}],
		},
		{
			'target_name'  : 'copy_binary',
			'type'         : 'none',
			'dependencies' : ['make_directory'],
			'actions'      : [{
				'action_name' : 'Module copied.',
				'inputs'      : [],
				'outputs'     : ['binary'],
				'action'      : ['<(cp)', 'build/Release/MY_ADDON.node', 'binary/MY_ADDON.node'],
			}],
		},
		
		{
			'target_name'  : 'remove_extras',
			'type'         : 'none',
			'dependencies' : ['copy_binary'],
			'actions'      : [{
				'action_name' : 'Build intermediates removed.',
				'inputs'      : [],
				'outputs'     : ['cpp'],
				'conditions'  : [
					[ 'OS=="linux"', { 'action' : [
						'rm',
						'<(module_root_dir)/build/Release/obj.target/MY_ADDON/cpp/MY_ADDON.o',
						'<(module_root_dir)/build/Release/obj.target/MY_ADDON.node',
						'<(module_root_dir)/build/Release/MY_ADDON.node'
					] } ],
					[ 'OS=="mac"', { 'action' : [
						'rm',
						'<(module_root_dir)/build/Release/obj.target/MY_ADDON/cpp/MY_ADDON.o',
						'<(module_root_dir)/build/Release/MY_ADDON.node'
					] } ],
					[ 'OS=="win"', { 'action' : [
						'<(_del)',
						'<(module_root_dir)/build/Release/MY_ADDON.*',
						'<(module_root_dir)/build/Release/obj/MY_ADDON/*.*'
					] } ],
				],
			}],
		},
		
	]
}
```

</details>


---

## include/addon-tools.hpp

There is a C++ header file, `addon-tools.hpp`, shipped with this package. It
introduces several useful macros and utilities. Also it includes Nan automatically,
so that you can replace:

```
// #include <v8.h> // node.h includes it
// #include <node.h> // nan.h includes it
#include <nan.h>
```

with

```
#include <addon-tools.hpp>
```

In gyp, the include directory should be set for your addon to know where to get it.
As it was mentioned above, this can be done automatically. Also an actual path to the
directory is exported from the module and is accessible like this:

```
require('addon-tools-raub').include() // implicit console.log()
require('addon-tools-raub').includePath // just a string
```

In the file, currently there are following helpers:


#### Handle scope

* `NAN_HS` - creates a HandleScope. Also, you do not need them within `NAN_METHOD`,
`NAN_SETTER`, and `NAN_GETTER`, as it is stated in
[Nan doc](https://github.com/nodejs/nan/blob/master/doc/methods.md#api_nan_method).
So it is most likely to be used in parts of code called from C++ land.

```
void windowFocusCB(GLFWwindow *window, int focused) { NAN_HS;
	...
}
...
glfwSetWindowFocusCallback(window, windowFocusCB);
```


#### Method return

* `RET_VALUE(VAL)` - set method return value
* `RET_UNDEFINED` - set method return value as undefined


#### New JS value

* `JS_STR(...)` - create a string value
* `JS_UTF8(...)` - same as JS_STR
* `JS_INT(val)` - create an integer value
* `JS_INT32(val)` - same as `JS_INT`
* `JS_UINT32(val)` - same as `JS_INT`
* `JS_NUM(val)` - create a numeric value
* `JS_OFFS(val)` - same as `JS_NUM`, but has a cast designed to avoid `size_t -> double` warning
* `JS_FLOAT(val)` - same as `JS_NUM`
* `JS_DOUBLE(val)` - same as `JS_NUM`
* `JS_EXT(val)` - create an external (pointer) value
* `JS_BOOL(val)` - create a boolean value
* `JS_FUN(val)` - get a function from persistent.
* `JS_OBJ(val)` - get an object from persistent.


#### Method check

These checks throw JS TypeError if not passed. Here `T` is always used as a typename
in error messages. `C` is
[v8::Value](https://v8docs.nodesource.com/node-0.8/dc/d0a/classv8_1_1_value.html)
check method, like `IsObject()`. `I` is the index of argument as in `info[I]`,
starting from `0`.

* `REQ_ARGS(N)` - check if at least `N` arguments passed
* `IS_ARG_EMPTY(I)` - check if argument `I` is `undefined` or `null`
* `CHECK_REQ_ARG(I, C, T)` - check if argument `I` is approved by `C` check.
* `CHECK_LET_ARG(I, C, T) - check if argument `I` is approved by `C` check or empty.
* `CTOR_CHECK(T)` - check if method is called as a constructor
* `SETTER_CHECK(C, T)` - check if setter `value` is approved by `C` check.
* `DES_CHECK` - within dynamic method check if the instance wasn't destroyed by `_destroy()`.


#### Method arguments

Two types of argument retrieval are supported: `REQ_` and `LET_`. The difference
is that `LET_` allows the argument to be empty, using some zero-default in this case.
`I` is the index of argument as in `info[I]`,
starting from `0`. `VAR` is the name of the `Local<Value>` variable to be created.

* `REQ_UTF8_ARG(I, VAR)` - require `I`'th argument to be a `string`. Stored at `Nan::Utf8String VAR`.
* `LET_UTF8_ARG(I, VAR)` - let optional `I`'th argument to be a `string`, the default is `""`. Stored at `Nan::Utf8String VAR`.
* `REQ_STR_ARG(I, VAR)` - require `I`'th argument to be a `string`. Stored at `Nan::Utf8String VAR`.
* `LET_STR_ARG(I, VAR)` - let optional `I`'th argument to be a `string`, the default is `""`. Stored at `Nan::Utf8String VAR`.
* `REQ_INT32_ARG(I, VAR)` - require `I`'th argument to be a `number`. Stored at `int VAR`.
* `LET_INT32_ARG(I, VAR)` - let optional `I`'th argument to be a `number`, the default is `0`. Stored at `int VAR`.
* `REQ_INT32_ARG(I, VAR)` - require `I`'th argument to be a `number`. Stored at `int VAR`.
* `LET_INT32_ARG(I, VAR)` - let optional `I`'th argument to be a `number`, the default is `0`. Stored at `int VAR`.
* `REQ_UINT32_ARG(I, VAR)` - require `I`'th argument to be a `number`. Stored at `unsigned VAR`.
* `LET_UINT32_ARG(I, VAR)` - let optional `I`'th argument to be a `number`, the default is `0`. Stored at `unsigned VAR`.
* `REQ_BOOL_ARG(I, VAR)` - require `I`'th argument to be a `boolean`. Stored at `bool VAR`.
* `LET_BOOL_ARG(I, VAR)` - let optional `I`'th argument to be a `boolean`, the default is `""`. Stored at `Nan::Utf8String VAR`.
* `REQ_OFFS_ARG(I, VAR)` - require `I`'th argument to be a `number`. Stored at `size_t VAR`.
* `LET_OFFS_ARG(I, VAR)` - let optional `I`'th argument to be a `number`, the default is `""`. Stored at `Nan::Utf8String VAR`.
* `REQ_DOUBLE_ARG(I, VAR)` - require `I`'th argument to be a `number`. Stored at `double VAR`.
* `LET_DOUBLE_ARG(I, VAR)` - let optional `I`'th argument to be a `number`, the default is `""`. Stored at `Nan::Utf8String VAR`.
* `REQ_FLOAT_ARG(I, VAR)` - require `I`'th argument to be a `number`. Stored at `float VAR`.
* `LET_FLOAT_ARG(I, VAR)` - let optional `I`'th argument to be a `number`, the default is `""`. Stored at `Nan::Utf8String VAR`.
* `REQ_EXT_ARG(I, VAR)` - require `I`'th argument to be an `external`. Stored at `Local<External> VAR`.
* `LET_EXT_ARG(I, VAR)` - let optional `I`'th argument to be an `external`, the default is `""`. Stored at `Nan::Utf8String VAR`.
* `REQ_FUN_ARG(I, VAR)` - require `I`'th argument to be a `function`. Stored at `Local<Function> VAR`.
* `REQ_OBJ_ARG(I, VAR)` - require `I`'th argument to be an `object`. Stored at `Local<Object> VAR`.
* `REQ_ARRV_ARG(I, VAR)` - require `I`'th argument to be a `TypedArray`. Stored at `Local<ArrayBufferView> VAR`.

```
NAN_METHOD(test) {
	
	REQ_UINT32_ARG(0, width);
	REQ_UINT32_ARG(1, height);
	LET_FLOAT_ARG(2, z);
	// Variables created: unsigned int width, height; float z;
	...
```

NOTE: The conversion from `Nan::Utf8String` to `std::string` (via `char *`) is possible with unary `*` operator.


#### Set properties

Set-helpers for string and numeric keys. String keys are converted to JS strings
automatically.

* `SET_PROP(OBJ, KEY, VAL)`
* `SET_I(ARR, I, VAL)`


#### Set object accessors

Simplified accessor assignment, adds accessors of NAME for OBJ. Read accessor is
assumed to have the name `NAME+'Getter'` and write accessor is `NAME+'Setter'`.

* `ACCESSOR_RW(OBJ, NAME)` - add read and write accessors of NAME for OBJ.
* `ACCESSOR_R(OBJ, NAME)` - read-only property.

```
void MyClass::init(Handle<Object> target) {
	...
	Local<ObjectTemplate> proto = ctor->PrototypeTemplate();
	ACCESSOR_RW(proto, message);
	...
}
NAN_GETTER(MyClass::messageGetter) { ...
NAN_SETTER(MyClass::messageSetter) { ...
```


#### Setter argument

Useful addition to NAN_SETTER macro. Works similar to method arguments. But there
is always only one required argument stored in `v`.

* `SETTER_UTF8_ARG` - require the value to be a `string`. Stored at `Nan::Utf8String v`.
* `SETTER_STR_ARG` - require the value to be a `string`. Stored at `Nan::Utf8String v`.
* `SETTER_INT32_ARG` - require the value to be a `number`. Stored at `int v`.
* `SETTER_INT_ARG` - require the value to be a `number`. Stored at `int v`.
* `SETTER_UINT32_ARG` - require the value to be a `number`. Stored at `unsigned v`.
* `SETTER_BOOL_ARG` - require the value to be a `boolean`. Stored at `bool v`.
* `SETTER_OFFS_ARG` - require the value to be a `number`. Stored at `size_t v`.
* `SETTER_DOUBLE_ARG` - require the value to be a `number`. Stored at `double v`.
* `SETTER_FLOAT_ARG` - require the value to be a `number`. Stored at `float v`.
* `SETTER_EXT_ARG` - require the value to be an `external`. Stored at `Local<External> v`.
* `SETTER_FUN_ARG` - require the value to be a `function`. Stored at `Local<Function> v`.
* `SETTER_OBJ_ARG` - require the value to be an `object`. Stored at `Local<Object> v`.
* `SETTER_ARRV_ARG` - require the value to be a `TypedArray`. Stored at `Local<ArrayBufferView> v`.

```
NAN_SETTER(MyClass::messageSetter) { SETTER_UTF8_ARG;
	// Variable created: Nan::Utf8String v;
	...
```


#### Data retrieval

* `T *getArrayData(value, num = NULL)` - extracts TypedArray data of any type from
the given JS value. Does not accept Array, checked with `IsArrayBufferView()`.
Returns `NULL` for empty JS values. For unacceptable values throws TypeError.


* `BYTE *getImageData(value)` - if value is a TypedArray, then the result of
`getArrayData(value)` is returned. Otherwise if value has `'data'` property, it's
content is then returned as `node::Buffer`. Returns `NULL` for empty JS values.
For unacceptable values throws TypeError.


---

## index.js

Exports:
* `paths(dir)` - function. Returns a set of platform dependent paths depending on
input `dir`.
	* `bin()` - prints platform binary path.
	* `rem()` - prints a space-separated list of binary paths to be cleaned on this platform.
	* `include()` - prints include directory for this `dir`.
	* `binPath` - platform binary path.
	* `remPath` - a space-separated list of binary paths to be cleaned on this platform.
	* `includePath` - include directory for this `dir`.
* `root()` - prints where `'addon-tools-raub'` module is situated.
* `include()` - prints both `'addon-tools-raub'` and `'nan'` include paths. Use with
`node -e` through list context command expansion `<!@(...)`
* `rm()` - prints the location of `'_rm.bat'` file on Windows and plain `rm` on Unix.
* `cp()` - prints the location of `'_cp.bat'` file on Windows and plain `cp` on Unix.
* `mkdir()` - prints the location of `'_mkdir.bat'` file on Windows and plain `mkdir` on Unix.
* `rootPath` - where `'addon-tools-raub'` module is situated.
* `includePath` - both `'addon-tools-raub'` and `'nan'` include paths.
* `rmPath` - the location of `'_rm.bat'` file on Windows and plain `rm` on Unix.
* `cpPath` - the location of `'_cp.bat'` file on Windows and plain `cp` on Unix.
* `mkdirPath` - the location of `'_mkdir.bat'` file on Windows and plain `mkdir` on Unix.


---

## Cross-platform commands

Because of the differences between Windows and Unix command shells, often a whole
lot of conditions have to be introduced in **binding.gyp** file. Now some of
them can be easily omitted with the new crossplatform commands, supplied by this
package.

This comes especially handy together with GYP's executable list expansion. For
example a list of files to be removed for cleaning. Or a list of unnecessary
binaries to be removed upon installation of a binary-dependency package.


### mkdir

On Unix, it will be an actual system `mkdir`, whereas on Windows it will use the
**mkdir.bat** file, located at the root of this package. This BAT file behaves
as if it was a `mkdir -p ...` call. You can still pass `-p` switch, which is
ignored. And the limitation is that you can not create a relative-path **-p**
folder. This can possibly be bypassed by supplying `./-p` or something like this.


```
'variables': {
	'mkdir' : '<!(node -e "require(\'addon-tools-raub\').mkdir()")',
},
...
'action' : ['<(mkdir)', '-p', 'binary'],
```


### rm

Disregard `del` vs `rd` aspect of Windows command line. Now the same command can
be used on all platforms to remove single and multiple files and directories.

```
'variables': {
	'rm'  : '<!(node -e "require(\'addon-tools-raub\').rm()")',
	'rem' : '<!(node -e "require(\'.\').rem()")',
},
...
'action' : ['<(rm)', '-rf', '<@(rem)'],
```

### cp

For Windows the `/y` flag was embedded.

```
'variables': {
	'cp'  : '<!(node -e "require(\'addon-tools-raub\').cp()")',
},
...
'action' : ['<(cp)', 'a', 'b'],
```

---


## class EventEmitter

A C++ implementation of [Events API](https://nodejs.org/api/events.html).

NOTE: This implementation has some minor deviations from the above standard.
Specifically there is no static `EventEmitter.defaultMaxListeners` property.
However the dynamic one persists and is infinite (`0`) by default.

An example can be found in **examples/node-addon** directory.
There is `Example` class, implemented in **cpp/example.cpp**, that inherits
EventEmitter behavior and is exported to JS.

For the C++ side `EventEmitter` has following public methods:

* `void emit(const std::string &name, int argc = 0, v8::Local<v8::Value> *argv = NULL)`
emits an event with the given `name` and, optionally, some additional arguments where
`argc` is the number of arguments and `argv` is a pointer to the arguments array.

* `void on(const std::string &name, v8::Local<v8::Value> that, const std::string &method)`
subscribes `that[method]` to receive `name` events from this emitter, basically
`emitter.on(name, that[method])`.

* `virtual void _destroy()` - destroys the object, i.e. deactivates it and frees
resources, also emitting a `'destroy'` event. This is what also called inside
`~EventEmitter()`, but only the first call is effective anyway.


Be sure to add the include directory in **binding.gyp**:

```
	'include_dirs': [
		'<!@(node -e "require(\'addon-tools-raub\').include()")',
	],
```

Though it is the same directory for all the **addon-tools**.
Then include the **event-emitter.hpp**, it also includes **addon-tools.hpp**.
Inherit from `EventEmitter`, it already inherits from `Nan::ObjectWrap`:

```
#include <event-emitter.hpp>

class Example : public EventEmitter {
	...
}
```

NOTE: Do not forget to call `EventEmitter::init()` once, in the module `init()`.


Now that everything is in place, consider providing **V8** with JS inheritance info:

```
void Example::init(Handle<Object> target) {
	
	Local<FunctionTemplate> proto = Nan::New<FunctionTemplate>(newCtor);
	
	// -------------------------- HERE!
	// class Example extends EventEmitter
	Local<FunctionTemplate> parent = Nan::New(EventEmitter::_prototype);
	proto->Inherit(parent);
	// --------------------------
	
	proto->InstanceTemplate()->SetInternalFieldCount(1);
	proto->SetClassName(JS_STR("Example"));
	
	Local<Function> ctor = Nan::GetFunction(proto).ToLocalChecked();
	
	_prototype.Reset(proto);
	
	Nan::Set(target, JS_STR("Example"), ctor);
	
}
```