是否可以从JS显式调用导出的Go WebAssembly函数? [英] Is it possible to explicitly call an exported Go WebAssembly function from JS?
问题描述
是否可以在Javascript中调用除 main
之外的Go WebAssembly函数?
Is it possible to call a Go WebAssembly function, other than main
, in Javascript?
首先让我展示一下我做了什么.我的Go函数定义如下:
Let me first show what I did. My Go functions are defined as follows:
package main
import "fmt"
func main() {
fmt.Println("it works!")
}
func add(a, b int) int {
return a + b
}
我只能调用 main
函数:
const go = new Go();
const data = await fetch("http://localhost:3333/main.wasm");
const result = await WebAssembly.instantiateStreaming(data, go.importObject);
go.run(result.instance);
返回它正常工作!
.
但是,每当我尝试调用 add
函数时,都会收到 TypeError:无法读取Welcome.getWasm
上未定义的属性"add",因为这两个result.exports
, result.instance.exports
不包含我的功能.我也尝试大写Go函数,但无济于事.
However, whenever I try to invoke the add
function, I receive TypeError: Cannot read property 'add' of undefined at Welcome.getWasm
, because both result.exports
, result.instance.exports
do not contain my function. I also tried capitalizing the Go function, but at no avail.
因此,我开始怀疑是什么问题– 是否甚至可以从Javascript调用随机Go函数?还是只能调用默认的 main()
功能?
Thus, I started wondering what could be a problem – is it even possible to call a random Go function from Javascript? Or can I only call the default main()
function?
推荐答案
是的,有可能.您可以将函数导出"到全局上下文(即浏览器中的窗口,在nodejs中为全局):
Yes, it is possible. You can "export" a function to the global context (i.e. window in browser, global in nodejs):
js.Global().Set("add", js.FuncOf(addFunction))
其中"add"是可用于从Javascript(window.add)调用函数的名称,"addFunction"是Go代码中位于主代码旁边的Go函数.
Where "add" is the name that you can use to call the function from Javascript (window.add) and "addFunction" is a Go function in your Go code, next to your main.
请注意,"addFunction"必须遵循该方法签名:
Note that "addFunction" must follow that method signature:
package main
import (
"syscall/js"
)
func addFunction(this js.Value, p []js.Value) interface{} {
sum := p[0].Int() + p[1].Int()
return js.ValueOf(sum)
}
func main() {
c := make(chan struct{}, 0)
js.Global().Set("add", js.FuncOf(addFunction))
<-c
}
在"go.run(result.instance);"之后您可以运行.
After "go.run(result.instance);" you can run.
go.run(result.instance);
add(100,200);
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