xhr.go

package xhr

import (
	"bytes"
	"io"
	"io/ioutil"
	"net/http"
	"net/textproto"

	"github.com/dop251/goja"
	"github.com/dop251/goja_nodejs/eventloop"
)

var program *goja.Program

// Enable ...
func Enable(r *goja.Runtime, loop *eventloop.EventLoop) {
	r.Set("__xhr__", xhr(loop))
	_, err := r.RunProgram(program)
	if err != nil {
		panic(err)
	}
}

func xhr(loop *eventloop.EventLoop) func(goja.FunctionCall) goja.Value {
	return func(call goja.FunctionCall) goja.Value {
		if fn, ok := goja.AssertFunction(call.Argument(1)); ok {
			o := call.Argument(0).Export().(map[string]interface{})
			go func() {
				var body io.Reader
				method := http.MethodGet
				header := make(http.Header)

				if headers, ex := o["headers"]; ex {
					if hmap, okh := headers.(map[string]interface{}); okh {
						for key, value := range hmap {
							v := value.([]interface{})
							for _, item := range v {
								var i []string
								i = append(i, item.(string))
								header[textproto.CanonicalMIMEHeaderKey(key)] = i
							}
						}
					}
				}

				if b, ex := o["body"]; ex {
					if bo, ok := b.(string); ok {
						body = bytes.NewBufferString(bo)
					}
				}

				if m, ex := o["method"]; ex {
					if me, ok := m.(string); ok {
						method = me
					}
				}

				var url string

				if u, ex := o["url"]; ex {
					if ur, ok := u.(string); ok {
						url = ur
					} else {
						panic("bad url")
					}
				}

				var toRet map[string]interface{}

				req, err := http.NewRequest(method, url, body)
				if err != nil {
					toRet = map[string]interface{}{
						"status": 0,
					}
				} else {
					req.Header = header

					res, err := http.DefaultClient.Do(req)
					if err != nil {
						toRet = map[string]interface{}{
							"status": 0,
						}
					} else {
						toRet = map[string]interface{}{
							"headers":    res.Header,
							"status":     res.StatusCode,
							"statusText": res.Status,
							"method":     method,
							"url":        url,
						}
					}
				}

				loop.RunOnLoop(func(r *goja.Runtime) {
					fn(nil, r.ToValue(toRet))
				})
			}()
		}
		return nil
	}
}

func init() {
	b, err := ioutil.ReadFile("xhr.js")
	if err != nil {
		panic(err)
	}
	program = goja.MustCompile("xhr.js", string(b), false)
}

xhr.js

var __goxhr__ = global.__xhr__;
delete global.__xhr__;

function XMLHttpRequest() {
  // console.log("create a xhr")
}

XMLHttpRequest.UNSENT = 0
XMLHttpRequest.OPENED = 1
XMLHttpRequest.HEADERS_RECEIVED = 2
XMLHttpRequest.LOADING = 3
XMLHttpRequest.DONE = 4

XMLHttpRequest.prototype = {
  open: function (method, url, async) {
    // console.log("opened a xhr", method, url, async);
    this.__method = method
    this.__url = url
    this.__async = !!async
    this._updateReadyState(XMLHttpRequest.OPENED)
  },
  setRequestHeader: function (name, value) {
    this.__headers || (this.__headers = {})
    this.__headers[name] = value
  },

  send: function (body) {
    // console.log("xhr send");
    var that = this
    __goxhr__({
      url: this.__url,
      method: this.__method,
      headers: this.__headers,
      body: body
    }, function (res) {
      // console.log("xhr got response")//, JSON.stringify(res));
      that.status = res.status
      that.statusText = res.statusText
      that.responseHeaders = res.headers
      that.responseText = res.body
      that._updateReadyState(XMLHttpRequest.DONE)
    })
    this._updateReadyState(XMLHttpRequest.LOADING)
  },

  getResponseHeader: function (name) {
    // console.log("get response header");
    this.responseHeaders || (this.responseHeaders = {})
    return this.responseHeaders[name]
  },

  getAllResponseHeaders: function () {
    // console.log("get all response headers")
    this.responseHeaders || (this.responseHeaders = {});
    var keys = Object.keys(this.responseHeaders)
    var str = ""

    for (var i = keys.length; i <= 0; i--) {
      str += keys[i] + ": " + this.responseHeaders[keys[i]] + "\n"
    }

    return str
  },

  _updateReadyState: function (state) {
    // console.log("set ready state:", state)
    this.readyState = state
    if (typeof this.onreadystatechange == 'function') {
      this.onreadystatechange()
    }
  }
};