/
reloader.js.go
191 lines (161 loc) · 4.43 KB
/
reloader.js.go
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package livepkg
// jsreloader is the default file reloader
const jsreloader = `
var Reloader = {};
(function(Reloader){
"use strict";
Reloader.ReloadAfter = 2000;
var xhr = new XMLHttpRequest();
var src = (PkgJSON || document.currentScript.src.replace(".js", ".json"));
xhr.open("GET", src);
xhr.onreadystatechange = function(){
if(xhr.readyState !== 4){ return; }
if(xhr.status != 200){
window.setTimeout(window.location.reload, Reloader.ReloadAfter);
return;
}
var result = JSON.parse(xhr.responseText);
LoadFiles(result.files);
if(typeof WebSocket !== 'undefined'){
ListenChanges(result.live);
}
};
xhr.send();
var loading = {};
var unloaded = [];
Reloader.loading = loading;
Reloader.unloaded = unloaded;
function LoadFiles(files){
unloaded = files;
flush();
var loadMonitor = window.setInterval(flush, 100);
// tries to load as many unblocked files as possible
function flush(){
// clear loaded
for(var name in loading){
var asset = document.getElementById("~" + name);
if(typeof asset === 'undefined'){ continue; }
if((asset.readyState === 'complete') ||
(asset.readyState === 'loaded')){
delete loading[name];
}
}
// try load something new
while(unloaded.length > 0){
if(!tryLoad(unloaded[0])){
return;
};
unloaded.shift();
}
// done?
if(Object.keys(loading).length == 0){
console.log("reloader", "+++");
window.clearInterval(loadMonitor);
}
}
// tries to load a file, returns true if it started loading
function tryLoad(file){
for(var i = 0; i < file.deps.length; i += 1){
if(loading[file.deps[i]]){ return false; }
}
console.log("reloader", "+ " + file.path);
loading[file.path] = true;
var asset = injectFile(file);
asset.onreadystatechange = flush;
asset.onload = function(){
delete loading[file.path];
flush();
};
asset.onerror = function(){
delete loading[file.path];
flush();
};
return true;
}
}
function makeDOMElement(file){
switch(file.ext){
case ".js":
var asset = document.createElement("script");
asset.src = file.path + "?" + Math.random();
break;
case ".css":
var asset = document.createElement("link");
asset.href = file.path + "?" + Math.random();
asset.rel = "stylesheet";
break;
default:
return;
}
asset.id = "~" + file.path;
return asset;
}
function injectFile(file){
var asset = makeDOMElement(file);
document.getElementsByTagName('head')[0].appendChild(asset);
return asset;
}
function removeFile(file){
var previous = document.getElementById("~" + file.path);
previous.parentNode.removeChild(previous);
}
function swapFile(prev, next){
var next = makeDOMElement(next);
var prev = document.getElementById(next.id);
prev.parentNode.insertBefore(next, prev);
setTimeout(function(){
prev.parentNode.removeChild(prev);
}, 20);
return next;
}
function reload(){
window.location.reload();
}
function onFileChanged(change){
return function(){
console.log("reloader", "%", change);
Reloader.Change && Reloader.Change(change);
Reloader.onchange && Reloader.onchange(change);
};
}
var OnceConnected = false;
var ConnectionDelay = 100;
function ListenChanges(livepath){
if(livepath == null){ return; }
var ws = new WebSocket("ws://" + window.location.host + livepath);
ws.addEventListener('message', function(ev){
if(ev.data === "") { return; }
var change = JSON.parse(ev.data);
if(change.deps){
reload();
return;
}
if(change.prev == null){
var asset = injectFile(change.next);
asset.onload = onFileChanged(change);
} else if(change.next == null){
removeFile(change.prev);
} else {
var asset = swapFile(change.prev, change.next);
asset.onload = onFileChanged(change);
}
});
ws.addEventListener('open', function(){
console.log("livepkg connected");
if(OnceConnected){
// server changed, force reload
window.location.reload();
}
OnceConnected = true;
});
ws.addEventListener('close', function(ev){
console.log("livepkg disconnected", ev);
window.setTimeout(function(){ ListenChanges(livepath); }, ConnectionDelay);
ConnectionDelay *= 2;
if(ConnectionDelay > 5000){
ConnectionDelay = 5000;
}
});
}
})(Reloader);
`