将Go函数传递给html / js按钮“ onclick”响应

Question

I am using Go's "net/http" package to pass data between the html and the backend in Go. For example, we can used the location of an image like this:

<img src={{.MyPicture}} width=200 height=auto/>

We can do the same thing to pass in functions to the html and call them:

{{if .MyBool}}
    {{.MyFunction}}
{{end}}

---

Now my question is: how do I set the response of a button to call my function? I would expect this to work, but it doesn't:

<button onclick={{.ShowMoreLinks}}>Show more!</button>

I get "[js] Declaration or statement expected." I've tried wrapping it in a script (both inline and in the header), but neither of these seem to work. JS can't handle the passed in variable.

Answer 1

Actually, you're using Go's template mechanism to prepare the HTML that you send to the browser. This only fills in placeholders and ultimately only produces a string (in this case HTML) that will be sent over the network to the browser for interpretation. It's the browser that can only handle interactivity with the user via events such as "onclick". Furthermore, these events have to be Javascript code, like a JS expression or a function call:

onclick="jsFunction()"

You could make your Go template provide the function to be called in the placeholder:

onclick="{{.JSFuncCall}}"

Here ".JSFuncCall" would have to evaluate to some JS function name (and the parentheses to make the call) that you must have defined in your JS client-side code. That Javascript function could then make an XHR call to the server at some specific URL that triggers a Go handler, runs the Go code you want to run, and then returns a response that you can then handle back in the JS function.