Tag Archives: jQuery

Dragging a File from File Explorer Causes Google Chrome to Crash

Hey everyone,

A team member found an interesting bug today that caused chrome to go non-responsive. The cause was simply dragging a file from the file explorer onto a drag and drop upload area. It is reproducible on every site I’ve tested, including Gmail and Dropbox.

Reproduce

  • Go to https://mail.google.com
  • Click compose
  • Click attach files (close any of the annoying popups that appear)
  • DRAG a number of files from the file selector window to the new message screen (they will start to upload) (IMPORTANT: these need to be dragged from the file selector popup, NOT a new explorer window)
  • While they are still uploading hit cancel on the file browser window. Browser will go non-responsive

A bug has been reported here: https://code.google.com/p/chromium/issues/detail?id=388661

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Refresh a Page with JavaScript

Hey everyone,

Just a quick post on how to force a page refresh with JavaScript (no jQuery required):

location.reload();

Note that the reload function accepts a boolean parameter that can be used for force a server refresh. Alternatively, it just defaults to the cache.

Checkout this Stackoverflow post for more info: http://stackoverflow.com/a/5404869/522859

Detecting FileSize – jQuery

Hey everyone,

Just a quick post on how to detect a file’s size with jQuery. I’m currently using a version of this for basic client side validation:



    Upload image:
    

$(document).ready(function(){
    $('#image-file').bind('change', function() {
        
        var fileSize = this.files && this.files.length > 0 && this.files[0].size ? this.files[0].size / 1024 / 1024 : 0;
        
        if(fileSize > 0){
            $('body').append('
' + fileSize + ' MB
'); } else{ $('body').append('
' + fileSize + ' MB
'); } }); });
.file{
padding: 5px 7px;
border-radius: 3px;
background-color: green;
color: white;
margin: 5px;
}

.file.valid{
background-color: rgb(127, 197, 127);
}

.file.invalid{
background-color: rgb(197, 127, 127);
}

Here’s the link to the full fiddle: http://jsfiddle.net/nLLMF/

There’re also a whole heap of other options listed on this StackOverflow post if you’re chasing something a bit more robust: http://stackoverflow.com/a/13249924/522859

http://jsfiddle.net/nLLMF/embedded/

Rails Flash Messages in MVC4

Hey everyone,

Coming from Rails I’d grown quite fond of flash messages. Unfortunately there isn’t a built in way of doing this in MVC4. Luckily, there’s a five minute solution posted on StackOverflow: http://stackoverflow.com/a/11809178/522859

Once implemented, it works just like in Rails:

this.Flash("We need you to login before you can edit anything.", FlashEnum.Warning);

Definitely worth checking out if you’ve got time, even more so if you’ve come over from Rails!

Twitter Bootstrap – Carousel Only CSS

Hey everyone,

I ran into a bit of an issue today with my stylesheet conflicting with Bootstrap. After a bit of tinkering I realised that all I really needed from bootstrap were the Carousel styles. I’ve taken everything else out and included everything that’s left below:

.carousel {
  position: relative;
}
.carousel-inner {
  position: relative;
  overflow: hidden;
  width: 100%;
}
.carousel-inner > .item {
  display: none;
  position: relative;
  -webkit-transition: 0.6s ease-in-out left;
  transition: 0.6s ease-in-out left;
}
.carousel-inner > .item > img,
.carousel-inner > .item > a > img {
  line-height: 1;
}
.carousel-inner > .active,
.carousel-inner > .next,
.carousel-inner > .prev {
  display: block;
}
.carousel-inner > .active {
  left: 0;
}
.carousel-inner > .next,
.carousel-inner > .prev {
  position: absolute;
  top: 0;
  width: 100%;
}
.carousel-inner > .next {
  left: 100%;
}
.carousel-inner > .prev {
  left: -100%;
}
.carousel-inner > .next.left,
.carousel-inner > .prev.right {
  left: 0;
}
.carousel-inner > .active.left {
  left: -100%;
}
.carousel-inner > .active.right {
  left: 100%;
}
.carousel-control {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 15%;
  opacity: .5;
  filter: alpha(opacity=50);
  font-size: 20px;
  color: #fff;
  text-align: center;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);
}
.carousel-control.left {
  background-image: -webkit-linear-gradient(left, color-stop(rgba(0, 0, 0, 0.5) 0), color-stop(rgba(0, 0, 0, 0.0001) 100%));
  background-image: linear-gradient(to right, rgba(0, 0, 0, 0.5) 0, rgba(0, 0, 0, 0.0001) 100%);
  background-repeat: repeat-x;
  filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#80000000', endColorstr='#00000000', GradientType=1);
}
.carousel-control.right {
  left: auto;
  right: 0;
  background-image: -webkit-linear-gradient(left, color-stop(rgba(0, 0, 0, 0.0001) 0), color-stop(rgba(0, 0, 0, 0.5) 100%));
  background-image: linear-gradient(to right, rgba(0, 0, 0, 0.0001) 0, rgba(0, 0, 0, 0.5) 100%);
  background-repeat: repeat-x;
  filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#00000000', endColorstr='#80000000', GradientType=1);
}
.carousel-control:hover,
.carousel-control:focus {
  outline: none;
  color: #fff;
  text-decoration: none;
  opacity: .9;
  filter: alpha(opacity=90);
}
.carousel-control .icon-prev,
.carousel-control .icon-next,
.carousel-control .glyphicon-chevron-left,
.carousel-control .glyphicon-chevron-right {
  position: absolute;
  top: 50%;
  z-index: 5;
  display: inline-block;
}
.carousel-control .icon-prev,
.carousel-control .glyphicon-chevron-left {
  left: 50%;
}
.carousel-control .icon-next,
.carousel-control .glyphicon-chevron-right {
  right: 50%;
}
.carousel-control .icon-prev,
.carousel-control .icon-next {
  width: 20px;
  height: 20px;
  margin-top: -10px;
  margin-left: -10px;
  font-family: serif;
}
.carousel-control .icon-prev:before {
  content: '2039';
}
.carousel-control .icon-next:before {
  content: '203a';
}
.carousel-indicators {
  position: absolute;
  bottom: 10px;
  left: 50%;
  z-index: 15;
  width: 60%;
  margin-left: -30%;
  padding-left: 0;
  list-style: none;
  text-align: center;
}
.carousel-indicators li {
  display: inline-block;
  width: 10px;
  height: 10px;
  margin: 1px;
  text-indent: -999px;
  border: 1px solid #fff;
  border-radius: 10px;
  cursor: pointer;
  background-color: #000 9;
  background-color: rgba(0, 0, 0, 0);
}
.carousel-indicators .active {
  margin: 0;
  width: 12px;
  height: 12px;
  background-color: #ffffff;
}
.carousel-caption {
  position: absolute;
  left: 15%;
  right: 15%;
  bottom: 20px;
  z-index: 10;
  padding-top: 20px;
  padding-bottom: 20px;
  color: #fff;
  text-align: center;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);
}
.carousel-caption .btn {
  text-shadow: none;
}
@media screen and (min-width: 768px) {
  .carousel-control .glyphicon-chevron-left,
  .carousel-control .glyphicon-chevron-right,
  .carousel-control .icon-prev,
  .carousel-control .icon-next {
    width: 30px;
    height: 30px;
    margin-top: -15px;
    margin-left: -15px;
    font-size: 30px;
  }
  .carousel-caption {
    left: 20%;
    right: 20%;
    padding-bottom: 30px;
  }
  .carousel-indicators {
    bottom: 20px;
  }
}

Minified:

.carousel{position:relative}.carousel-inner{position:relative;overflow:hidden;width:100%}.carousel-inner>.item{display:none;position:relative;-webkit-transition:.6s ease-in-out left;transition:.6s ease-in-out left}.carousel-inner>.item>a>img,.carousel-inner>.item>img{line-height:1}.carousel-inner>.active,.carousel-inner>.next,.carousel-inner>.prev{display:block}.carousel-inner>.active{left:0}.carousel-inner>.next,.carousel-inner>.prev{position:absolute;top:0;width:100%}.carousel-inner>.next{left:100%}.carousel-inner>.prev{left:-100%}.carousel-inner>.next.left,.carousel-inner>.prev.right{left:0}.carousel-inner>.active.left{left:-100%}.carousel-inner>.active.right{left:100%}.carousel-control{position:absolute;top:0;left:0;bottom:0;width:15%;opacity:.5;filter:alpha(opacity=50);font-size:20px;color:#fff;text-align:center;text-shadow:0 1px 2px rgba(0,0,0,.6)}.carousel-control.left{background-image:-webkit-linear-gradient(left,color-stop(rgba(0,0,0,.5)0),color-stop(rgba(0,0,0,.0001)100%));background-image:linear-gradient(to right,rgba(0,0,0,.5)0,rgba(0,0,0,.0001)100%);background-repeat:repeat-x;filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#80000000', endColorstr='#00000000', GradientType=1)}.carousel-control.right{left:auto;right:0;background-image:-webkit-linear-gradient(left,color-stop(rgba(0,0,0,.0001)0),color-stop(rgba(0,0,0,.5)100%));background-image:linear-gradient(to right,rgba(0,0,0,.0001)0,rgba(0,0,0,.5)100%);background-repeat:repeat-x;filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#00000000', endColorstr='#80000000', GradientType=1)}.carousel-control:focus,.carousel-control:hover{outline:0;color:#fff;text-decoration:none;opacity:.9;filter:alpha(opacity=90)}.carousel-control .glyphicon-chevron-left,.carousel-control .glyphicon-chevron-right,.carousel-control .icon-next,.carousel-control .icon-prev{position:absolute;top:50%;z-index:5;display:inline-block}.carousel-control .glyphicon-chevron-left,.carousel-control .icon-prev{left:50%}.carousel-control .glyphicon-chevron-right,.carousel-control .icon-next{right:50%}.carousel-control .icon-next,.carousel-control .icon-prev{width:20px;height:20px;margin-top:-10px;margin-left:-10px;font-family:serif}.carousel-control .icon-prev:before{content:'2039'}.carousel-control .icon-next:before{content:'203a'}.carousel-indicators{position:absolute;bottom:10px;left:50%;z-index:15;width:60%;margin-left:-30%;padding-left:0;list-style:none;text-align:center}.carousel-indicators li{display:inline-block;width:10px;height:10px;margin:1px;text-indent:-999px;border:1px solid #fff;border-radius:10px;cursor:pointer;background-color:#000 9;background-color:rgba(0,0,0,0)}.carousel-indicators .active{margin:0;width:12px;height:12px;background-color:#fff}.carousel-caption{position:absolute;left:15%;right:15%;bottom:20px;z-index:10;padding-top:20px;padding-bottom:20px;color:#fff;text-align:center;text-shadow:0 1px 2px rgba(0,0,0,.6)}.carousel-caption .btn{text-shadow:none}@media screen and (min-width:768px){.carousel-control .glyphicon-chevron-left,.carousel-control .glyphicon-chevron-right,.carousel-control .icon-next,.carousel-control .icon-prev{width:30px;height:30px;margin-top:-15px;margin-left:-15px;font-size:30px}.carousel-caption{left:20%;right:20%;padding-bottom:30px}.carousel-indicators{bottom:20px}}

Let me know if you have any other issues.

How to Get a JavaScript Stack Trace – Chrome Console

Hey everyone,

Just a quick post on something useful I came across today. In JavaScript you can access the stack trace via console using the following command (ctrl + shift + j):

console.trace()

In Chrome, this will let you navigate to each relevant call by clicking the line number in the console window. I’ve found it pretty useful for backtracking through jQuery exceptions.

For more info, check out this Stackoverflow post: http://stackoverflow.com/q/6715571/522859

JSON Issue: This request has been blocked because sensitive information – MVC

Hey everyone,

Started redoing Learner Lessons in MVC4 and AngularJS today. I ran into this little issue while trying to retrieve JSON:

This request has been blocked because sensitive information could be disclosed to third party web sites when this is used in a GET request. To allow GET requests, set JsonRequestBehavior to AllowGet

It turns out that this behavious is intentionally prevented in order to avoid JSON hijacking. Thankfully the data I’m working with is not at all sensitive so the workaround is pretty straight forward:

public ActionResult Index()
{
     return Json(db.Regions.ToList(), JsonRequestBehavior.AllowGet);
}

Source: http://stackoverflow.com/a/4616442/522859

For those of you working with sensitive data that don’t want to risk exposing it, posting is suggested as an alternative on StackOverflow: http://stackoverflow.com/a/6440163/522859