从c ++调用带有参数的v8 javascript函数 [英] Calling a v8 javascript function from c++ with an argument
问题描述
我使用c ++和v8,并遇到以下挑战:我想能够使用v8在javascript中定义一个函数,然后通过c ++调用该函数。此外,我想能够传递一个参数到c ++的javascript函数。我认为下面的示例源代码将解释最好。检查示例代码的末尾,看看我想要完成什么。
I am working with c++ and v8, and have run into the following challenge: I want to be able to define a function in javascript using v8, then call the function later on through c++. Additionally, I want to be able to pass an argument to the javascript function from c++. I think the following sample source code would explain it best. Check towards the end of the sample code to see what I am trying to accomplish.
#include <v8.h>
#include <iostream>
#include <string>
#include <array>
using namespace v8;
int main(int argc, char* argv[]) {
// Create a stack-allocated handle scope.
HandleScope handle_scope;
// Create a new context.
Persistent<Context> context = Context::New();
Context::Scope context_scope(context);
Handle<String> source;
Handle<Script> script;
Handle<Value> result;
// Create a string containing the JavaScript source code.
source = String::New("function test_function(test_arg) { var match = 0;if(test_arg[0] == test_arg[1]) { match = 1; }");
// Compile the source code.
script = Script::Compile(source);
// What I want to be able to do (this part isn't valid code..
// it just represents what I would like to do.
// An array is defined in c++ called pass_arg,
// then passed to the javascript function test_function() as an argument
std::array< std::string, 2 > pass_arg = {"value1", "value2"};
int result = script->callFunction("test_function", pass_arg);
}
有任何提示吗?
UPDATE:
根据给出的建议,我已经能够编写以下代码。它已经过测试和工作:
Based on the advice given, I have been able to put together the following code. It has been tested and works:
#include <v8.h>
#include <iostream>
#include <string>
using namespace v8;
int main(int argc, char* argv[]) {
// Create a stack-allocated handle scope.
HandleScope handle_scope;
// Create a new context.
Persistent<Context> context = Context::New();
//context->AllowCodeGenerationFromStrings(true);
// Enter the created context for compiling and
// running the hello world script.
Context::Scope context_scope(context);
Handle<String> source;
Handle<Script> script;
Handle<Value> result;
// Create a string containing the JavaScript source code.
source = String::New("function test_function() { var match = 0;if(arguments[0] == arguments[1]) { match = 1; } return match; }");
// Compile the source code.
script = Script::Compile(source);
// Run the script to get the result.
result = script->Run();
// Dispose the persistent context.
context.Dispose();
// Convert the result to an ASCII string and print it.
//String::AsciiValue ascii(result);
//printf("%s\n", *ascii);
Handle<v8::Object> global = context->Global();
Handle<v8::Value> value = global->Get(String::New("test_function"));
Handle<v8::Function> func = v8::Handle<v8::Function>::Cast(value);
Handle<Value> args[2];
Handle<Value> js_result;
int final_result;
args[0] = v8::String::New("1");
args[1] = v8::String::New("1");
js_result = func->Call(global, 2, args);
String::AsciiValue ascii(js_result);
final_result = atoi(*ascii);
if(final_result == 1) {
std::cout << "Matched\n";
} else {
std::cout << "NOT Matched\n";
}
return 0;
}
推荐答案
测试这个,但是这样的东西可能会工作:
I haven't tested this, but it's possible that something like this will work:
// ...define and compile "test_function"
Handle<v8::Object> global = context->Global();
Handle<v8::Value> value = global->Get(String::New("test_function"));
if (value->IsFunction()) {
Handle<v8::Function> func = v8::Handle<v8::Function>::Cast(value);
Handle<Value> args[2];
args[0] = v8::String::New("value1");
args[1] = v8::String::New("value2");
Handle<Value> js_result = func->Call(global, 2, args);
if (js_result->IsInt32()) {
int32_t result = js_result->ToInt32().Value();
// do something with the result
}
}
编辑:
看起来你的javascript函数需要一个参数的两个值),但它看起来像我们通过传递两个参数调用 func
。
It looks like your javascript function expects a single argument (consisting of an array of two values), but it kinda looks like we're calling func
by passing in two arguments.
测试这个假设,你可以改变你的javascript函数接受两个参数并比较它们,例如:
To test this hypothesis, you could change your javascript function to take two arguments and compare them, e.g.:
function test_function(test_arg1, test_arg2) {
var match = 0;
if (test_arg1 == test_arg2) {
match = 1;
} else {
match = 0;
}
return match;
}
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