Approaches to SSR with v8go

1-approach.md

First Approach

Fastest one. The idea is to run SSR script, get function with sensitive args and run it.

iso object has Isolate *v8go.Isolate and RenderScript *v8go.UnboundScript (it was compiled before).

Go Code

// renderer.go
// ...

func (r *Renderer) Render(urlPath string) (string, error) {
	iso := r.pool.Get()
	defer r.pool.Put(iso)

	ctx := v8go.NewContext(iso.Isolate)
	defer ctx.Close()

	iso.RenderScript.Run(ctx)

	renderCmd := fmt.Sprintf(`ssrRender("%s")`, urlPath)
	val, err := ctx.RunScript(renderCmd, r.ssrScriptName)
	if err != nil {
		if jsErr, ok := err.(*v8go.JSError); ok {
			err = fmt.Errorf("%v", jsErr.StackTrace)
		}
		return "", nil
	}

	return val.String(), nil
}

JS Code

// entry-server.ts
// ...

function ssrRender(url: string) {
  return render(url).then((html) => {
    return html
  })
}

(globalThis as any).ssrRender = ssrRender

2-approach.md

Second Approach

Create global object in Go with render function that recieves rendered html, concat string in Go and return.

Go Code

iso object has Isolate *v8go.Isolate and RenderScript *v8go.UnboundScript (it was compiled before).

// renderer.go
// ...

func (r *Renderer) Render(urlPath string) (string, error) {
	iso := r.pool.Get()
	defer r.pool.Put(iso)

	outputHTML := ""
	
	ssrObject := v8go.NewObjectTemplate(iso.Isolate)
	ssrObject.Set("href", urlPath)
	ssrObject.Set("render", v8go.NewFunctionTemplate(iso.Isolate, func(info *v8go.FunctionCallbackInfo) *v8go.Value {
		args := info.Args()
		if len(args) > 0 {
			outputHTML = args[0].String()
		}
		return nil
	}))
	
	globalObject := v8go.NewObjectTemplate(iso.Isolate)
	globalObject.Set("ssr", ssrObject)
	
	ctx := v8go.NewContext(iso.Isolate, globalObject)
  defer ctx.Close()
	
	start := time.Now()
	iso.RenderScript.Run(ctx)
	//if _, err := ctx.RunScript(r.scriptSource, r.Path); err != nil {
	//	return "", err
	//}
	fmt.Println("Script run:", time.Since(start))
	
	return outputHTML, nil
}

JS Code

// entry-server.ts
// ...

if (typeof ssr !== 'undefined') {
  render(ssr.href).then((html) => {
    ssr.render(html)
  })
}