hugo/livereload/livereload.go

// Copyright 2015 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Contains an embedded version of livereload.js
//
// Copyright (c) 2010-2015 Andrey Tarantsov
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

package livereload

import (
	"fmt"
	"net/http"
	"path/filepath"

	"github.com/gorilla/websocket"
)

// Prefix to signal to LiveReload that we need to navigate to another path.
const hugoNavigatePrefix = "__hugo_navigate"

var upgrader = &websocket.Upgrader{ReadBufferSize: 1024, WriteBufferSize: 1024}

// Handler is a HandlerFunc handling the livereload
// Websocket interaction.
func Handler(w http.ResponseWriter, r *http.Request) {
	ws, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		return
	}
	c := &connection{send: make(chan []byte, 256), ws: ws}
	wsHub.register <- c
	defer func() { wsHub.unregister <- c }()
	go c.writer()
	c.reader()
}

// Initialize starts the Websocket Hub handling live reloads.
func Initialize() {
	go wsHub.run()
}

// ForceRefresh tells livereload to force a hard refresh.
func ForceRefresh() {
	RefreshPath("/x.js")
}

// NavigateToPath tells livereload to navigate to the given path.
// This translates to `window.location.href = path` in the client.
func NavigateToPath(path string) {
	RefreshPath(hugoNavigatePrefix + path)
}

// RefreshPath tells livereload to refresh only the given path.
// If that path points to a CSS stylesheet or an image, only the changes
// will be updated in the browser, not the entire page.
func RefreshPath(s string) {
	// Tell livereload a file has changed - will force a hard refresh if not CSS or an image
	urlPath := filepath.ToSlash(s)
	wsHub.broadcast <- []byte(`{"command":"reload","path":"` + urlPath + `","originalPath":"","liveCSS":true,"liveImg":true}`)
}

// ServeJS serves the liverreload.js who's reference is injected into the page.
func ServeJS(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/javascript")
	w.Write(liveReloadJS())
}

func liveReloadJS() []byte {
	return []byte(livereloadJS + hugoLiveReloadPlugin)
}

var (
	// This is temporary patched with this PR (enables sensible error messages):
	// https://github.com/livereload/livereload-js/pull/64
	// TODO(bep) replace with distribution once merged.
	livereloadJS         = `(function e(t,n,o){function i(s,l){if(!n[s]){if(!t[s]){var c=typeof require=="function"&&require;if(!l&&c)return c(s,!0);if(r)return r(s,!0);var a=new Error("Cannot find module '"+s+"'");throw a.code="MODULE_NOT_FOUND",a}var h=n[s]={exports:{}};t[s][0].call(h.exports,function(e){var n=t[s][1][e];return i(n?n:e)},h,h.exports,e,t,n,o)}return n[s].exports}var r=typeof require=="function"&&require;for(var s=0;s<o.length;s++)i(o[s]);return i})({1:[function(e,t,n){(function(){var t,o,i,r,s,l;l=e("./protocol"),r=l.Parser,o=l.PROTOCOL_6,i=l.PROTOCOL_7;s="2.2.2";n.Connector=t=function(){function e(e,t,n,o){this.options=e;this.WebSocket=t;this.Timer=n;this.handlers=o;this._uri="ws"+(this.options.https?"s":"")+"://"+this.options.host+":"+this.options.port+"/livereload";this._nextDelay=this.options.mindelay;this._connectionDesired=false;this.protocol=0;this.protocolParser=new r({connected:function(e){return function(t){e.protocol=t;e._handshakeTimeout.stop();e._nextDelay=e.options.mindelay;e._disconnectionReason="broken";return e.handlers.connected(t)}}(this),error:function(e){return function(t){e.handlers.error(t);return e._closeOnError()}}(this),message:function(e){return function(t){return e.handlers.message(t)}}(this)});this._handshakeTimeout=new n(function(e){return function(){if(!e._isSocketConnected()){return}e._disconnectionReason="handshake-timeout";return e.socket.close()}}(this));this._reconnectTimer=new n(function(e){return function(){if(!e._connectionDesired){return}return e.connect()}}(this));this.connect()}e.prototype._isSocketConnected=function(){return this.socket&&this.socket.readyState===this.WebSocket.OPEN};e.prototype.connect=function(){this._connectionDesired=true;if(this._isSocketConnected()){return}this._reconnectTimer.stop();this._disconnectionReason="cannot-connect";this.protocolParser.reset();this.handlers.connecting();this.socket=new this.WebSocket(this._uri);this.socket.onopen=function(e){return function(t){return e._onopen(t)}}(this);this.socket.onclose=function(e){return function(t){return e._onclose(t)}}(this);this.socket.onmessage=function(e){return function(t){return e._onmessage(t)}}(this);return this.socket.onerror=function(e){return function(t){return e._onerror(t)}}(this)};e.prototype.disconnect=function(){this._connectionDesired=false;this._reconnectTimer.stop();if(!this._isSocketConnected()){return}this._disconnectionReason="manual";return this.socket.close()};e.prototype._scheduleReconnection=function(){if(!this._connectionDesired){return}if(!this._reconnectTimer.running){this._reconnectTimer.start(this._nextDelay);return this._nextDelay=Math.min(this.options.maxdelay,this._nextDelay*2)}};e.prototype.sendCommand=function(e){if(this.protocol==null){return}return this._sendCommand(e)};e.prototype._sendCommand=function(e){return this.socket.send(JSON.stringify(e))};e.prototype._closeOnError=function(){this._handshakeTimeout.stop();this._disconnectionReason="error";return this.socket.close()};e.prototype._onopen=function(e){var t;this.handlers.socketConnected();this._disconnectionReason="handshake-failed";t={command:"hello",protocols:[o,i]};t.ver=s;if(this.options.ext){t.ext=this.options.ext}if(this.options.extver){t.extver=this.options.extver}if(this.options.snipver){t.snipver=this.options.snipver}this._sendCommand(t);return this._handshakeTimeout.start(this.options.handshake_timeout)};e.prototype._onclose=function(e){this.protocol=0;this.handlers.disconnected(this._disconnectionReason,this._nextDelay);return this._scheduleReconnection()};e.prototype._onerror=function(e){};e.prototype._onmessage=function(e){return this.protocolParser.process(e.data)};return e}()}).call(this)},{"./protocol":6}],2:[function(e,t,n){(function(){var e;e={bind:function(e,t,n){if(e.addEventListener){return e.addEventListener(t,n,false)}else if(e.attachEvent){e[t]=1;return e.attachEvent("onpropertychange",function(e){if(e.propertyName===t){return n()}})}else{throw new Error("Attempt to attach custom event "+t+" to something which isn't a DOMElement")}},fire:function(e,t){var n;if(e.addEventList
	hugoLiveReloadPlugin = fmt.Sprintf(`
/*
Hugo adds a specific prefix, "__hugo_navigate", to the path in certain situations to signal
navigation to another content page.
*/

function HugoReload() {}

HugoReload.identifier = 'hugoReloader';
HugoReload.version = '0.9';

HugoReload.prototype.reload = function(path, options) {
	var prefix = %q;

	if (path.lastIndexOf(prefix, 0) !== 0) {
		return false
	}

	path = path.substring(prefix.length);
	window.location.href = path;

	return true;
};

LiveReload.addPlugin(HugoReload)
`, hugoNavigatePrefix)
)