Develop Reference

Clearing multiple timeouts properly

I've been struggling for the past day trying to solve this one.
I'm trying to get some funky text effects going, basically a glorified string creation.
It writes a line a bit like a billboard and to do it I've used setTimeout.
Thing is I would like to put it in a function so I can reuse it and call it multiple times on different elements.
The problem is that I then need to update the text maybe halfway to a new text.
To do so I clear the timeout, but unless the timer variable is outside the scope it doesn't clear.
I can't really have it outside the function because of practicality;
I'm not sure how many times it is going to be called and it just feels wrong to declare 20 time variables outside the function.
Here's the code working CORRECTLY on one item
(click multiple times to interrupt and restart)
var t;
function writeStats(str,dest) {
var options = {
"step" : 8, // How many times should the letters be changed
"fps" : 25, // Frames Per Second
"text" : "" // Use this text instead of the contents
}
function randomChar(type){
var pool = "";
if (type == "lowerLetter"){
pool = "abcdefghijklmnopqrstuvwxyz0123456789";
}
else if (type == "upperLetter"){
pool = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
}
else if (type == "symbol"){
pool = ",.?/\\(^)![]{}*&^%$#'\"";
}
var arr = pool.split('');
return arr[Math.floor(Math.random()*arr.length)];
}
str = str.split('');
var types = [],
letters = [];
for(var i=0;i<str.length;i++){
var ch = str[i];
if(ch == " "){
types[i] = "space";
continue;
}
else if(/[a-z]/.test(ch)){
types[i] = "lowerLetter";
}
else if(/[A-Z]/.test(ch)){
types[i] = "upperLetter";
}
else {
types[i] = "symbol";
}
letters.push(i);
}
clearTimeout(t);
(function shuffle(start){
// This code is run options.fps times per second
// and updates the contents of the page element
var i,
len = letters.length,
strCopy = str.slice(0); // Fresh copy of the string
if(start>len){
return;
}
// All the work gets done here
for(i=Math.max(start,0); i < len; i++){
// The start argument and options.step limit
// the characters we will be working on at once
if( i < start+options.step){
// Generate a random character at this position
strCopy[letters[i]] = randomChar(types[letters[i]]);
}
else {
strCopy[letters[i]] = "";
}
}
//el.text(strCopy.join(""));
el = strCopy.join("");
//console.log(el);
$('.'+dest).text(el);
t = setTimeout(function(){
shuffle(start+1);
},500/options.fps);
})(-options.step);
}
$(document).ready(function(){
$(document).click(function(){
writeStats('this sentence is a great one','t1');
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<div class="t1"></div>
<div class="t2"></div>
and a Fiddle script: https://jsfiddle.net/phjzfw15/
If I bring the t variable inside the function like so it doesn't work as before:
function writeStats(str,dest) {
var t;
var options = {
"step" : 8, // How many times should the letters be changed
"fps" : 25, // Frames Per Second
"text" : "" // Use this text instead of the contents
}
function randomChar(type){
var pool = "";
if (type == "lowerLetter"){
pool = "abcdefghijklmnopqrstuvwxyz0123456789";
}
else if (type == "upperLetter"){
pool = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
}
else if (type == "symbol"){
pool = ",.?/\\(^)![]{}*&^%$#'\"";
}
var arr = pool.split('');
return arr[Math.floor(Math.random()*arr.length)];
}
str = str.split('');
var types = [],
letters = [];
for(var i=0;i<str.length;i++){
var ch = str[i];
if(ch == " "){
types[i] = "space";
continue;
}
else if(/[a-z]/.test(ch)){
types[i] = "lowerLetter";
}
else if(/[A-Z]/.test(ch)){
types[i] = "upperLetter";
}
else {
types[i] = "symbol";
}
letters.push(i);
}
clearTimeout(t);
(function shuffle(start){
// This code is run options.fps times per second
// and updates the contents of the page element
var i,
len = letters.length,
strCopy = str.slice(0); // Fresh copy of the string
if(start>len){
return;
}
// All the work gets done here
for(i=Math.max(start,0); i < len; i++){
// The start argument and options.step limit
// the characters we will be working on at once
if( i < start+options.step){
// Generate a random character at this position
strCopy[letters[i]] = randomChar(types[letters[i]]);
}
else {
strCopy[letters[i]] = "";
}
}
//el.text(strCopy.join(""));
el = strCopy.join("");
//console.log(el);
$('.'+dest).text(el);
t = setTimeout(function(){
shuffle(start+1);
},500/options.fps);
})(-options.step);
}
$(document).ready(function(){
$(document).click(function(){
writeStats('this sentence is a great one','t1');
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<div class="t1"></div>
<div class="t2"></div>
... and the relative fiddle if you prefer it there: https://jsfiddle.net/phjzfw15/1/
If you run the snippet you'll see it doesn't work properly anymore.
Clicking repeatedly will show you that the old sentence is still there and it gets overwritten.
How can I get this working clearing the timeout correctly inside the function?
I thought the "t" variable was local to each function and a separate instance of it would have been created?
Thanks!

Ok, here's a dumbed down version (maybe the amount of code was too much before)
CORRECT VERSION
var starr = [
'bloop the boop',
'cammy the shadow',
'i like cauliflower',
'bro, i kick u hard',
'like measels? I dont.',
'eat fish and pie'
];
var timer;
function writeStats(str, dest) {
$('.'+dest).text('');
var options = {
"step" : 8, // How many times should the letters be changed
"fps" : 25, // Frames Per Second
"text" : "" // Use this text instead of the contents
}
str = str.split('');
clearTimeout(timer);
var ll = '';
(function shuffle(start){
// This code is run options.fps times per second
// and updates the contents of the page element
var i, len = str.length, el;
if(start>=len){
return;
}
ll = ll + str[start];
$('.'+dest).text(ll);
timer = setTimeout(function(){
shuffle(start+1);
},1500/options.fps);
})(0);
}
$(document).ready(function(){
var index = 0;
$(document).click(function(){
writeStats(starr[index],'t1');
if (index == 5) index = 0; else index++;
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js"></script>
Correct version
<div class="t1">Click anywhere multiple times</div>
NOT WORKING VERSION
var starr = [
'bloop the boop',
'cammy the shadow',
'i like cauliflower',
'bro, i kick u hard',
'like measels? I dont.',
'eat fish and pie'
];
function writeStats(str, dest) {
var timer;
$('.'+dest).text('');
var options = {
"step" : 8, // How many times should the letters be changed
"fps" : 25, // Frames Per Second
"text" : "" // Use this text instead of the contents
}
str = str.split('');
clearTimeout(timer);
var ll = '';
(function shuffle(start){
// This code is run options.fps times per second
// and updates the contents of the page element
var i, len = str.length, el;
if(start>=len){
return;
}
ll = ll + str[start];
$('.'+dest).text(ll);
timer = setTimeout(function(){
shuffle(start+1);
},1500/options.fps);
})(0);
}
$(document).ready(function(){
var index = 0;
$(document).click(function(){
writeStats(starr[index],'t1');
if (index == 5) index = 0; else index++;
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
NOT WORKING VERSION (please note I just moved the timer declaration inside the function)
<div class="t1">Click anywhere multiple times fast</div>

Finally made it to work.
For posterities...
var starr = [
'bloop the boop',
'cammy the shadow',
'i like cauliflower',
'bro, i kick u hard',
'like measels? I dont.',
'eat fish and pie'
];
var writer = function(){
var timer;
this.writeStat = function(str,dest) {
var options = { "step" : 8, "fps" : 25, "text" : "" }
str = str.split('');
clearTimeout(timer);
var ll = '';
(function shuffle(start){
// This code is run options.fps times per second
// and updates the contents of the page element
var i, len = str.length, el;
if(start>=len){
return;
}
ll = ll + str[start];
$('.'+dest).text(ll);
timer = setTimeout(function(){
shuffle(start+1);
},1500/options.fps);
})(0);
}
}
$(document).ready(function(){
var index = 0;
w = new writer;
y = new writer;
$(document).click(function(){
w.writeStat(starr[index],'t1');
y.writeStat(starr[index],'t2');
if (index == 5) index = 0; else index++;
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
<div class="t1"></div>
<div class="t2"></div>

Debugging Javascript in IE 8

I'm trying to debug an issue that I'm only having in IE8. It works fine in IE 9+, and chrome. I'm using Aspera to select a file, and am calling a custom function on a callback. the function is as follows;
function uploadPathsRecieved(pathsArray) {
var file_path_selector = '#file_path';
...
$(file_path_selector).text(''); // (*)
...
}
On the (*) line, I get an error that file_path_selector is undefined. This didn't make much sense to me, so after some playing around to get a feel for the problem, I wound up with the following code:
function uploadPathsRecieved(pathsArray) {
var x = 3;
var y = 4;
var z = x + y;
z += 2;
$('#file_path').text(''); // (*)
...
}
When I run the program with this code, I still get the error "file_path_selector is undefined" at the (*) line. I'm out of ideas on what the next steps I should take to try and hunt down this problem are.
My gut feeling tells me that there's something being cached, but if I move the (*) line around, the error follows it, and the script window reflects the changes that I make to it.
Here's the Aspera code that's calling my function:
function wrapCallbacks(callbacks) {
return wrapCallback(function() {
var args, i;
try {
args = Array.prototype.slice.call(arguments);
for ( i = 0; i < args.length; i++) {
if (isObjectAndNotNull(args[i]) && isDefined(args[i].error)) {
// error found
if (isDefined(callbacks.error)) {
callbacks.error.apply(null, args);
}
return;
}
}
// success
if (isDefined(callbacks.success)) {
callbacks.success.apply(null, args);
}
} catch (e) {
AW.utils.console.error(e.name + ": " + e.message);
AW.utils.console.trace();
}
});
}
And here's the entirety of my function, as it exists right now:
var uploadPathsRecieved = function uploadPathsRecieved(pathsArray) {
//var file_path_selector = '#file_path';
var x = 3;
var y = 4;
var z = x + y;
z += 2;
$('#file_path').text('');
var button_selector = '#select_aspera_file';
var textbox_selector = '.aspera_textbox';
/*if (uploadPathsRecieved.fileSelecting == 'cc_file') {
file_path_selector = '#cc_file_path';
button_selector = '#select_cc_file';
textbox_selector = '.cc_aspera_textbox';
} else if (uploadPathsRecieved.fileSelecting == 'preview_file') {
file_path_selector = '#preview_file_path';
button_selector = '#select_preview_file';
textbox_selector = '.preview_aspera_textbox';
}*/
App.AsperaUploadPaths = [];
if (pathsArray.length == 1) {
$(button_selector).text("Clear File");
App.AsperaUploadPaths = pathsArray;
var error_message = pathsArray[0];
$(button_selector).parent().children(textbox_selector).text(error_message).removeClass('error');
//$(file_path_selector).attr('value', pathsArray[0]);
}
else
{
var error_message = 'Please select a single file';
$(button_selector).parent().children(textbox_selector).text(error_message).addClass('error');
}
}

Solved it. file_path was an <input>, and IE 8 and below doesn't allow you to add text or html to inputs.
I fixed it by changing $(file_path_selector).text(''); to $(file_path_selector).attr('value', '');

Optimizing a loop to cut down on the number of draws

I'm creating an animated strip chart that redraws on every new packet message received from the header. First I create a function that checks if the chart already exists and if not builds it:
function drawAccel() {
if (chart == null) {
chart = Stripchart(document.getElementById('accel'));
}
if (orienteer == null) {
orienteer = Orienteer(document.getElementById('orienteer'));
}
chart.draw();
orienteer.draw();
}
Following that I run this function which loops and redraws the chart on every header packet recieved:
function messagecb(header, message) {
if(header.type == 6) {
// echo reply
// processEchoReply(message);
}else if(header.type == 4) {
// accel
var accels = message.b64UnpackAccelMsg();
for(var index in accels) {
var accel = accels[index];
var totalClock = accelEpochAdjust(accel.clock);
addAccelDatum(totalClock, accel.x, accel.y, accel.z);
}
drawAccel();
} else if(header.type == 3) {
// info
var info2 = message.b64UnpackInfo2Msg();
displayCurrentPosition(info2.fixtime, info2.lat, info2.lon, info2.alt);
displayMobileStatus(info2.rssi, info2.bandClass, info2.batt);
} else if(header.type == 11) {
btReceive(header, message);
}
}
I have no issues in all the modern browsers using this method, but in IE8 it really slows down a lot. This causes a slow running script error to occur which eventually ends up breaking the app. I also think something about my current logic is causing the chart to redraw even if the graph hasn't visually changed, but I'm unsure of how to check on that. Sorry for being long winded any help is greatly appreciated!

This might not be much help so please dont downvote.
I had a similar problem and only redrew every so many packets or over a set time frame like:
var mycars = new Array();
var count = 0;
function newPakcet(pck) {
mycars[mycars.length + 1] = pck;
redraw();
}
var redrawSize = 10;
function redraw(pck) {
if (mycars.length > 10) {
for(var i = 0 ;i < mycars.length;i++){
//Draw here
}
mycars = new Array();
}
}
Not tested it so there may be more syntax error.

After some trial and error along with a little help from some one else this ended up solving the problem. Set a local variable rather than a global to act as a counter that can be checked to see if it is a multiple of 10. Wrap the draw function with it so that it draws on every tenth packet.
function messagecb(header, message) {
if(header.type == 6) {
// processEchoReply(message);
} else if(header.type == 4) {
var accels = message.b64UnpackAccelMsg();
for(var index = 0; index < accels.length; ++index) {
var accel = accels[index];
var totalClock = accelEpochAdjust(accel.clock);
addAccelDatum(totalClock, accel.x, accel.y, accel.z);
}
if ( typeof messagecb.counter == 'undefined' ) {
messagecb.counter = 0;
}
++messagecb.counter;
if (messagecb.counter % 10 == 0) {
drawAccel();
}
} else if(header.type == 3) {
// info
var info2 = message.b64UnpackInfo2Msg();
displayCurrentPosition(info2.fixtime, info2.lat, info2.lon, info2.alt);
displayMobileStatus(info2.rssi, info2.bandClass, info2.batt);
} else if(header.type == 11) {
btReceive(header, message);
}
}

javascript abstract console logging

I want to make a function, like this.
For example:
function Logger() {
this.log = function(msg) {
console.log(msg);
}
}
And I want to use it in functions/modules etc, and that all works fine.
But the default console in my browser normally give the fileName + lineNumber.
Now when I abstract this functionality, the fileName and lineNumber is not where I put my instance.log(). Because it will say from where the console.log is being called, not the function itself.
So my question:
How can I get the correct information from where I want to use my logger?
Or give me, please, any tips to improve this functionality.

function Logger() {
this.log = console.log.bind(console);
}
I asked about this some time ago: Create shortcut to console.log() in Chrome.

Try using backtrace function like this one :
function printStackTrace() {
var callstack = [];
var isCallstackPopulated = false;
try {
i.dont.exist += 0; //doesn't exist- that's the point
} catch (e) {
if (e.stack) { //Firefox
var lines = e.stack.split('\n');
for (var i = 0, len = lines.length; i & lt; len; i++) {
if (lines[i].match(/^\s*[A-Za-z0-9\-_\$]+\(/)) {
callstack.push(lines[i]);
}
}
//Remove call to printStackTrace()
callstack.shift();
isCallstackPopulated = true;
}
else if (window.opera & amp; & amp; e.message) { //Opera
var lines = e.message.split('\n');
for (var i = 0, len = lines.length; i & lt; len; i++) {
if (lines[i].match(/^\s*[A-Za-z0-9\-_\$]+\(/)) {
var entry = lines[i];
//Append next line also since it has the file info
if (lines[i + 1]) {
entry += ' at ' + lines[i + 1];
i++;
}
callstack.push(entry);
}
}
//Remove call to printStackTrace()
callstack.shift();
isCallstackPopulated = true;
}
}
if (!isCallstackPopulated) { //IE and Safari
var currentFunction = arguments.callee.caller;
while (currentFunction) {
var fn = currentFunction.toString();
var fname = fn.substring(fn.indexOf( & amp; quot;
function & amp; quot;) + 8, fn.indexOf('')) || 'anonymous';
callstack.push(fname);
currentFunction = currentFunction.caller;
}
}
output(callstack);
}
function output(arr) {
//Optput however you want
alert(arr.join('\n\n'));
}

Try assigning the function:
(function () {
window.log = (console && console.log
? console.log
: function () {
// Alternative log
});
})();
Later just call log('Message') in your code.

javascript - Failed to load source for: http://localhost/js/m.js

Why oh why oh why... I can't figure out why I keep getting this error. I think I might cry.
/*** common functions */
function GE(id) { return document.getElementById(id); }
function changePage(newLoc) {
nextPage = newLoc.options[newLoc.selectedIndex].value
if (nextPage != "")
{
document.location.href = nextPage
}
}
function isHorizO(){
if (navigator.userAgent.indexOf('iPod')>-1)
return (window.orientation == 90 || window.orientation==-90)? 1 : 0;
else return 1;
}
function ShowHideE(el, act){
if (GE(el)) GE(el).style.display = act;
}
function KeepTop(){
window.scrollTo(0, 1);
}
/* end of common function */
var f = window.onload;
if (typeof f == 'function'){
window.onload = function() {
f();
init();
}
}else window.onload = init;
function init(){
if (GE('frontpage')) init_FP();
else {
if (GE('image')) init_Image();
setTimeout('window.scrollTo(0, 1)', 100);
}
AddExtLink();
}
function AddExtLink(){
var z = GE('extLink');
if (z){
z = z.getElementsByTagName('a');
if (z.length>0){
z = z[0];
var e_name = z.innerHTML;
var e_link = z.href;
var newOption, oSe;
if (GE('PSel')) oSe = new Array(GE('PSel'));
else
oSe = getObjectsByClassName('PSel', 'select')
for(i=0; i<oSe.length; i++){
newOption = new Option(e_name, e_link);
oSe[i].options[oSe[i].options.length] = newOption;
}
}
}
}
/* fp */
function FP_OrientChanged() {
init_FP();
}
function init_FP() {
// GE('orientMsg').style.visibility = (!isHorizO())? 'visible' : 'hidden';
}
/* gallery */
function GAL_OrientChanged(link){
if (!isHorizO()){
ShowHideE('vertCover', 'block');
GoG(link);
}
setTimeout('window.scrollTo(0, 1)', 500);
}
function init_Portfolio() {
// if (!isHorizO())
// ShowHideE('vertCover', 'block');
}
function ShowPortfolios(){
if (isHorizO()) ShowHideE('vertCover', 'none');
}
var CurPos_G = 1
function MoveG(dir) {
MoveItem('G',CurPos_G, dir);
}
/* image */
function init_Image(){
// check for alone vertical images
PlaceAloneVertImages();
}
function Img_OrtChanged(){
//CompareOrientation(arImgOrt[CurPos_I]);
//setTimeout('window.scrollTo(0, 1)', 500);
}
var CurPos_I = 1
function MoveI(dir) {
CompareOrientation(arImgOrt[CurPos_I+dir]);
MoveItem('I',CurPos_I, dir);
}
var arImgOrt = new Array(); // orientation: 1-horizontal, 0-vertical
var aModeName = new Array('Horizontal' , 'Vertical');
var arHs = new Array();
function getDims(obj, ind){
var arT = new Array(2);
arT[0] = obj.height;
arT[1] = obj.width;
//arWs[ind-1] = arT;
arHs[ind] = arT[0];
//**** (arT[0] > arT[1]) = (vertical image=0)
arImgOrt[ind] = (arT[0] > arT[1])? 0 : 1;
// todor debug
if(DebugMode) {
//alert("["+obj.width+","+obj.height+"] mode="+((arT[0] > arT[1])? 'verical' : 'hoziontal'))
writeLog("["+obj.width+","+obj.height+"] mode="+((arT[0] > arT[1])? 'verical' : 'hoziontal')+' src='+obj.src)
}
if (arImgOrt[ind]) {
GE('mi'+ind).className = 'mImageH';
}
}
function CompareOrientation(imgOrt){
var iPhoneOrt = aModeName[isHorizO()];
GE('omode').innerHTML = iPhoneOrt;
//alert(imgOrt == isHorizO())
var sSH = (imgOrt == isHorizO())? 'none' : 'block';
ShowHideE('vertCover', sSH);
var sL = imgOrt? 'H' : 'V';
if (GE('navig')) GE('navig').className = 'navig'+ sL ;
if (GE('mainimage')) GE('mainimage').className = 'mainimage'+sL;
var sPfL = imgOrt? 'Port-<br>folios' : 'Portfolios' ;
if (GE('PortLnk')) GE('PortLnk').innerHTML = sPfL;
}
function SetGetDim( iMInd){
var dv = GE('IImg'+iMInd);
if (dv) {
var arI = dv.getElementsByTagName('img');
if (arI.length>0){
var oImg = arI[0];
oImg.id = 'Img'+iMInd;
oImg.className = 'imageStyle';
//YAHOO.util.Event.removeListener('Img'+iMInd,'load');
YAHOO.util.Event.on('Img'+iMInd, 'load', function(){GetDims(oImg,iMInd);}, true, true);
//oImg.addEventListener('load',GetDims(oImg,iMInd),true);
}
}
}
var occ = new Array();
function PlaceAloneVertImages(){
var iBLim, iELim;
iBLim = 0;
iELim = arImgOrt.length;
occ[0] = true;
//occ[iELim]=true;
for (i=1; i<iELim; i++){
if ( arImgOrt[i]){//horizontal image
occ[i]=true;
continue;
}else { // current is vertical
if (!occ[i-1]){//previous is free-alone. this happens only the first time width i=1
occ[i] = true;
continue;
}else {
if (i+1 == iELim){//this is the last image, it is alone and vertical
GE('mi'+i).className = 'mImageV_a'; //***** expand the image container
}else {
if ( arImgOrt[i+1] ){
GE('mi'+i).className = 'mImageV_a';//*****expland image container
occ[i] = true;
occ[i+1] = true;
i++;
continue;
}else { // second vertical image
occ[i] = true;
occ[i+1] = true;
if (arHs[i]>arHs[i+1]) GE('mi'+(i+1)).style.height = arHs[i]+'px';
i++;
continue;
}
}
}
}
}
//arImgOrt
}
function AdjustWebSiteTitle(){
//if (GE('wstitle')) if (GE('wstitle').offsetWidth > GE('wsholder').offsetWidth) {
if (GE('wstitle')) if (GE('wstitle').offsetWidth > 325) {
ShowHideE('dots1','block');
ShowHideE('dots2','block');
}
}
function getObjectsByClassName(className, eLTag, parent){
var oParent;
var arr = new Array();
if (parent) oParent = GE(parent); else oParent=document;
var elems = oParent.getElementsByTagName(eLTag);
for(var i = 0; i < elems.length; i++)
{
var elem = elems[i];
var cls = elem.className
if(cls == className){
arr[arr.length] = elem;
}
}
return arr;
}
////////////////////////////////
///
// todor debug
var DebugMode = (getQueryVariable("debug")=="1")
function getQueryVariable(variable) {
var query = window.location.search.substring(1);
var vars = query.split("&");
var sRet = ""
for (var i=0;i<vars.length;i++) {
var pair = vars[i].split("=");
if (pair[0] == variable) {
sRet = pair[1];
}
}
return sRet
//alert('Query Variable ' + variable + ' not found');
}
var oLogDiv=''
function writeLog(sMes){
if(!oLogDiv) oLogDiv=document.getElementById('oLogDiv')
if(!oLogDiv) {
oLogDiv = document.createElement("div");
oLogDiv.style.border="1px solid red"
var o = document.getElementsByTagName("body")
if(o.length>0) {
o[0].appendChild(oLogDiv)
}
}
if(oLogDiv) {
oLogDiv.innerHTML = sMes+"<br>"+oLogDiv.innerHTML
}
}

First, Firebug is your friend, get used to it. Second, if you paste each function and some supporting lines, one by one, you will eventually get to the following.
var DebugMode = (getQueryVariable("debug")=="1")
function getQueryVariable(variable)
You can't execute getQueryVariable before it is defined, you can create a handle to a future reference though, there is a difference.
There are several other potential issues in your code, but putting the var DebugMode line after the close of the getQueryVariable method should work fine.

It would help if you gave more context. For example, is
Failed to load source for:
http://localhost/js/m.js
the literal text of an error message? Where and when do you see it?
Also, does that code represent the contents of http://localhost/js/m.js? It seems that way, but it's hard to tell.
In any case, the JavaScript that you've shown has quite a few statements that are missing their semicolons. There may be other syntax errors as well. If you can't find them on your own, you might find tools such as jslint to be helpful.

make sure the type attribute in tag is "text/javascript" not "script/javascript".

I know it is more than a year since this question was asked, but I faced this today. I had a
<script type="text/javascript" src="/test/test-script.js"/>
and I was getting the 'Failed to load source for: http://localhost/test/test-script.js' error in Firebug. Even chrome was no loading this script. Then I modified the above line as
<script type="text/javascript" src="/test/test-script.js"></script>
and it started working both in Firefox and chrome. Documenting this here hoping that this will help someone. Btw, I dont know why the later works where as the previous one didn't.