utils.go

package mixed

import (
	"net/http"

	echo "github.com/labstack/echo/v4"
)

// copyContext creates a new echo.Context with the same Request, Path, Params and Handler
// but with a Response that contains an in-memory ResponseWriter
func copyContext(c echo.Context, preserveKeys []string) echo.Context {
	cc := c.Echo().AcquireContext()
	cc.SetRequest(c.Request())
	cc.SetPath(c.Path())
	cc.SetParamNames(c.ParamNames()...)
	cc.SetParamValues(c.ParamValues()...)
	cc.SetHandler(c.Handler())

	for _, key := range preserveKeys {
		if val := c.Get(key); val != nil {
			cc.Set(key, val)
		}
	}

	rw := tempResponseWriter{
		header:  make(http.Header),
		Content: []byte{},
	}
	resp := echo.NewResponse(&rw, c.Echo())
	cc.SetResponse(resp)
	return cc
}

// copyResponse copy c2 headers and content into c1
func copyResponse(c1, c2 echo.Context, preserveKeys []string) {
	for _, key := range preserveKeys {
		if val := c2.Get(key); val != nil {
			c1.Set(key, val)
		}
	}

	for k, v := range c2.Response().Header() {
		for _, vv := range v {
			c1.Response().Header().Set(k, vv)
		}
	}

	if c2.Response().Status > 0 {
		c1.Response().WriteHeader(c2.Response().Status)
	}

	_, err := c1.Response().Write(c2.Response().Writer.(*tempResponseWriter).Content)
	if err != nil {
		panic(err)
	}
}