英文:
Can not pass parameters to js.Func
问题
我有以下代码，其中函数正确地附加到按钮的onclick事件上：
func f(this js.Value, args []js.Value) interface{} {
println("hello world")
return nil
}
btn.Set("onclick", js.FuncOf(f))
我尝试将参数传递给这个函数：
btn.Set("onclick", js.FuncOf(f).Invoke("Hello World"))
并在js.Func中进行操作：
for x := range args {
println(x)
}
但是我得到了错误：
wasm_exec.js:421 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'exports')
at syscall/js.valueInvoke (wasm_exec.js:421)
at syscall_js.valueInvoke (main.wasm:0x133521)
at syscall_js.Value.Invoke (main.wasm:0x131300)
at main.html (main.wasm:0x25b572)
at main.main (main.wasm:0x25e591)
at runtime.main (main.wasm:0x7f285)
at wasm_pc_f_loop (main.wasm:0xddf81)
at wasm_export_run (main.wasm:0xddf54)
at global.Go.run (wasm_exec.js:577)
at init (wasm.js:7)
有什么想法吗？
英文:
I've the below code where the function attached properly to the button onclick event:
func f(this js.Value, args []js.Value) interface{} {
println("hello world")
return nil
}
btn.Set("onclick", js.FuncOf(f))
I tried to pass args for this function as:
btn.Set("onclick", js.FuncOf(f).Invoke("Hello World"))
And manipulate it in the js.Func as:
for x := range args {
println(x)
}
But I got the error:
wasm_exec.js:421 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'exports')
at syscall/js.valueInvoke (wasm_exec.js:421)
at syscall_js.valueInvoke (main.wasm:0x133521)
at syscall_js.Value.Invoke (main.wasm:0x131300)
at main.html (main.wasm:0x25b572)
at main.main (main.wasm:0x25e591)
at runtime.main (main.wasm:0x7f285)
at wasm_pc_f_loop (main.wasm:0xddf81)
at wasm_export_run (main.wasm:0xddf54)
at global.Go.run (wasm_exec.js:577)
at init (wasm.js:7)
Any thought?
答案1
得分: 1
我使用.bind解决了这个问题，代码如下所示：
element.Set("onclick", js.FuncOf(f).Call("bind", e, args...))
// bind(event, arguments...), 作为(arguments..., event)传递给函数f
所以，我的代码变成了：
btn.Set("onclick", js.FuncOf(f).Call("bind", btn, "hi", "hello"))
func f(this js.Value, args []js.Value) interface{} {
for index, item := range args {
if x < len(args)-1 { // len(args)-1 是事件本身
println(index, item.String())
}
}
self := args[len(args)-1].Get("target")
// self = event.target == this
self.Get("style").Call("setProperty", "background-color", "red")
// 同样的效果:
// this.Get("style").Call("setProperty", "background-color", "red")
return nil
}
英文:
I solved it using .bind as below:
element.Set("onclick", js.FuncOf(f).Call("bind", e, args...))
// bind(event, arguments...), passed to function f as (arguments..., event)
So, my code become:
btn.Set("onclick", js.FuncOf(f).Call("bind", btn, "hi", "hello"))
func f(this js.Value, args []js.Value) interface{} {
for index, item := range args {
if x < len(args)-1 { // len(args)-1 is the event itself
println(index, item.String())
}
}
self := args[len(args)-1].Get("target")
// self = event.target == this
self.Get("style").Call("setProperty", "background-color", "red")
// same as:
// this.Get("style").Call("setProperty", "background-color", "red")
return nil
}
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