JavaScript runtime. More...

#include <OxygenEngine/ext/javascript.h>

Public Member Functions
void	addClass (CallableEntity class_info, const std::vector< CallableEntity > &methods)
	Add a class type available in JavaScript code.

void	addFunction (CallableEntity function_info)
	add a C function available in in JavaScript code

void	eval (const char *data)
	Evaluate a script in the current runtime.

Static Public Member Functions
static void	pushJson (duk_context *ctx, const nlohmann::json &data, bool is_object=true)
	push a nlhomann::json object as a json to the runtime

static nlohmann::json	getJson (duk_context *ctx, int index)
	pull a nlhomann::json object from a parameter

Public Attributes
duk_context *	ctx

Detailed Description

JavaScript runtime.

Can bind function calls to C functions

Usage:

oe::ext::js::Runtime js_runtime;
auto* ctx = js_runtime.ctx;
 
js_runtime.addClass(...);
js_runtime.addFunction(...);
 
js_runtime.eval(YOUR_SCRIPT_CODE);
 
// Call the function 'test' defined in JS, taking no arguments and returns a string
 
// Pushes "[global].test" into the stack
  duk_push_global_object(ctx);
  duk_get_prop_string(ctx, -1, "test");
 
// Call it (with 0 arguments)
duk_pcall(ctx, 0);
 
printf("test result is: %s\n", duk_safe_to_string(ctx, -1));

Here is another example where a class is defined and used as first argument:

// ... code from previous example ...
 
// Define a 'MyObject' class (callbacks are the same as the [Duktape tutorial about constructors](https://wiki.duktape.org/howtonativeconstructor))
js_runtime.addClass(
{
   .name = "MyObject",
   .callback = myobject_constructor,
   .callback_args_count = 1
},
{
   {
     .name = "printName",
     .callback = myobject_print_name,
     .callback_args_count = 1
   }
});
 
// Call the function 'test2' defined in JS, taking 1 argument of type MyObject (defined before) and returns a string
// Pushes "[global].test2" into the stack
  duk_get_global_string(ctx, "test2");
 
// Create an instance of MyObject with a member value of  gabuzomeu
  duk_get_global_string(ctx, "MyObject");
  duk_push_string(ctx, "gabuzomeu");
  duk_new(ctx, 1);
 
// Call it (with 1 arguments)
duk_pcall(ctx, 1);
 
printf("test2 result is: %s\n", duk_safe_to_string(ctx, -1));

Member Function Documentation

◆ addClass()

void oe::ext::js::Runtime::addClass	(	CallableEntity	class_info,
		const std::vector< CallableEntity > &	methods
	)

inline

Add a class type available in JavaScript code.

Note: No members definition here: In JavaScript this is done by the constructor

◆ eval()

void oe::ext::js::Runtime::eval ( const char * data )

inline

Evaluate a script in the current runtime.

This method may be called multiple times (for example when appending multiples JS files)

◆ getJson()

static nlohmann::json oe::ext::js::Runtime::getJson	(	duk_context *	ctx,
		int	index
	)

inlinestatic

pull a nlhomann::json object from a parameter

Used to fetch json parameters from C++ functions

◆ pushJson()

static void oe::ext::js::Runtime::pushJson	(	duk_context *	ctx,
		const nlohmann::json &	data,
		bool	is_object = `true`
	)

inlinestatic

push a nlhomann::json object as a json to the runtime

Parameters

ctx	Duktape context
data	JSON data
is_object	does the object should be sent as an object (true) or as an array (false)

Note: object sent as array will be silently ignored by Duktape and replaced by an empty array

The documentation for this struct was generated from the following file:

OxygenEngine/ext/javascript.h

Public Member Functions