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"If there’s a way for a site to take dependency on a browser quirk, and break if that quirk is..."

2012 Feb 1, 5:10
“If there’s a way for a site to take dependency on a browser quirk, and break if that quirk is removed, it will happen.”

- -Eric Lawrence, Web Browser Legend
PermalinkCommentstechnical eric-lawrence the-eric-lawrence browser web-browser compat

One-click, in-browser MP3 recording and hosting

2012 Jan 3, 2:48

Cool, although I was hoping this would be done in HTML and JS. Now that would be impressive.

PermalinkCommentsmp3 technical audio

JavaScript Array methods in the latest browsers

2011 Dec 3, 6:46

Cool and (relatively) new methods on the JavaScript Array object are here in the most recent versions of your favorite browser! More about them on ECMAScript5, MSDN, the IE blog, or Mozilla's documentation. Here's the list that's got me excited:

some & every
Does your callback function return true for any (some) or all (every) of the array's elements?
filter
Filters out elements for which your callback function returns false (in a new copy of the Array).
map
Each element is replaced with the result of it run through your callback function (in a new copy of the Array).
reduce & reduceRight
Your callback is called on each element in the array in sequence (from start to finish in reduce and from finish to start in reduceRight) with the result of the previous callback call passed to the next. Reduce your array to a single value aggregated in any manner you like via your callback function.
forEach
Simply calls your callback passing in each element of your array in turn. I have vague performance concerns as compared to using a normal for loop.
indexOf & lastIndexOf
Finds the first or last (respectively) element in the array that matches the provided value via strict equality operator and returns the index of that element or -1 if there is no such element. Surprisingly, no custom comparison callback method mechanism is provided.
PermalinkCommentsjavascript array technical programming

URI Empty Path Segments Matter

2011 Nov 23, 11:00

Shortly after joining the Internet Explorer team I got a bug from a PM on a popular Microsoft web server product that I'll leave unnamed (from now on UWS). The bug said that IE was handling empty path segments incorrectly by not removing them before resolving dotted path segments. For example UWS would do the following:

A.1. http://example.com/a/b//../
A.2. http://example.com/a/b/../
A.3. http://example.com/a/
In step 1 they are given a URI with dotted path segment and an empty path segment. In step 2 they remove the empty path segment, and in step 3 they resolve the dotted path segment. Whereas, given the same initial URI, IE would do the following:
B.1. http://example.com/a/b//../
B.2. http://example.com/a/b/
IE simply resolves the dotted path segment against the empty path segment and removes them both. So, how did I resolve this bug? As "By Design" of course!

The URI RFC allows path segments of zero length and does not assign them any special meaning. So generic user agents that intend to work on the web must not treat an empty path segment any different from a path segment with some text in it. In the case above IE is doing the correct thing.

That's the case for generic user agents, however servers may decide that a URI with an empty path segment returns the same resource as a the same URI without that empty path segment. Essentially they can decide to ignore empty path segments. Both IIS and Apache work this way and thus return the same resource for the following URIs:

http://exmaple.com/foo//bar///baz
http://example.com/foo/bar/baz
The issue for UWS is that it removes empty path segments before resolving dotted path segments. It must follow normal URI procedure before applying its own additional rules for empty path segments. Not doing that means they end up violating URI equivalency rules: URIs (A.1) and (B.2) are equivalent but UWS will not return the same resource for them.
PermalinkCommentsuser agent url ie uri technical web browser

Features of image type input tags in HTML

2011 Nov 21, 11:00

A bug came up the other day involving markup containing <input type="image" src="http://example.com/.... I knew that "image" was a valid input type but it wasn't until that moment that I realized I didn't know what it did. Looking it up I found that it displays the specified image and when the user clicks on the image, the form is submitted with an additional two name value pairs: the x and y positions of the point at which the user clicked the image.

Take for example the following HTML:

<form action="http://example.com/">
<input type="image" name="foo" src="http://deletethis.net/dave/images/davebefore.jpg">
</form>
If the user clicks on the image, the browser will submit the form with a URI like the following:http://example.com/?foo.x=145&foo.y=124.

This seemed like an incredibly specific feature to be built directly into the language when this could instead be done with javascript. I looked a bit further and saw that its been in HTML since at least HTML2, which of course makes much more sense. Javascript barely existed at that point and sending off the user's click location in a form may have been the only way to do something interesting with that action.

PermalinkCommentsuri technical form history html

Biden Minimizes Browser Window Every Time Obama Walks By

2011 Nov 17, 12:38PermalinkCommentshumor government obama biden onion

FireFox doesn't have innerText

2011 Nov 14, 12:34

I wrote my HTML against IE9 and continually validated with Chrome as I went. Afterward I tried it in FireFox and found out that FireFox has textContent whereas IE9 & Chrome have innerText

PermalinkCommentstechnical web web-browser firefox ie9 chrome ie innertext textcontent js html

[html5] Web Workers: Race-Condition setting onmessage handler?

2011 Sep 20, 7:17There's no race between posting to a web worker and the web worker setting up its message handler as long as the web worker sets its message handler in the first sync. block of code that runs in the web worker: "Basically, once the initial worker script returns, the worker's port is enabled and the normal message port event delivery mechanism kicks in (including dropping unhandled messages on the floor)."PermalinkCommentstechnical web-worker webbrowser programming postMessage

Eric Lawrence and Adam Barth on Strict-Transport-Security

2011 Aug 22, 9:27PermalinkCommentshttps http http-header technical strict-transport-security browser

draft-ietf-websec-origin-01 - The Web Origin Concept

2011 Jun 21, 1:22"This document defines the concept of an "origin", which is often used
as the scope of authority or privilege by user agents. Typically,
user agents isolate content retrieved from different origins to
prevent malicious web site operators from interfering with the
operation of benign web sites. In addition to outlining the
principles that underly the origin concept, this document defines how
to determine the origin of a URI, how to serialize an origin into a
string, and an HTTP header, named "Origin", that indicates which
origins are associated with an HTTP request."PermalinkCommentsietf reference technical web browser user-agent webbrowser origin

[whatwg] CORS requests for image and video elements

2011 May 23, 4:26Applying CORS to the media elements: "I've added a content attribute to <img>, <video>, and <audio> that makes the image or media resource be fetched with CORS And have the origin of the page if CORS succeeded. The attribute is "cross-origin" and it has two allowed values, "use-credentials" and "anonymous". The latter is the default, so you can just say <img cross-origin src="data.png">."PermalinkCommentscors crossdomain web browser webbrowser html technical

Chromium Blog: SSL FalseStart Performance Results

2011 May 22, 10:44Links to the IETF draft document of and describes the perf benefits of SSL False Start.PermalinkCommentssecurity google browser web webbrowser https performance ssl tls technical

draft-abarth-url-01 - Parsing URLs for Fun and Profit

2011 Apr 27, 3:12Prescriptive spec on URI parsing. "This document contains a precise specification of how browsers process URLs. The behavior specified in this document might or might not match any particular browser, but browsers might be well-served by adopting the behavior defined herein."PermalinkCommentstechnical rfc reference uri

JavaScript & .NET interop via WebBrowser Control

2011 Apr 5, 10:00

For my GeolocMock weekend project I intended to use the Bing Maps API to display a map in a WebBrowser control and allow the user to interact with that to select a location to be consumed by my application. Getting my .NET code to talk to the JavaScript in the WebBrowser control was surprisingly easy.

To have .NET execute JavaScript code you can use the InvokeScript method passing the name of the JavaScript function to execute and an object array of parameters to pass:

this.webBrowser2.Document.InvokeScript("onLocationStateChanged",
new object[] {
latitudeTextBoxText,
longitudeTextBoxText,
altitudeTextBoxText,
uncertaintyTextBoxText
});

The other direction, having JavaScript call into .NET is slightly more complicated but still pretty easy as far as language interop goes. The first step is to mark your assembly as ComVisible so that it can interact with JavaScript via COM. VS had already added a ComVisible declaration to my project I just had to change the value to true.

[assembly: ComVisible(true)]

Next set ObjectForScripting attribute to the object you want to expose to JavaScript.

this.webBrowser2.ObjectForScripting = this.locationState;

Now that object is exposed as window.external in JavaScript and you can call methods on it.

window.external.Set(lat, long, alt, gUncert);

However you don't seem to be able to test for the existence of methods off of it. For example the following JavaScript generates an exception for me even though I have a Set method:

if (window.external && window.external.Set) {
PermalinkCommentsjavascript webbrowser .net technical csharp

Using client-side storage, today. ✩ Mozilla Hacks – the Web developer blog

2011 Apr 5, 5:14A JS wrapper script that lets you use storage in IE6/7 via userData or localStorage every where else.PermalinkCommentsjavascript html web webbrowser storage technical userdata localstorage

IE9 Document Mode in WebOC

2011 Apr 4, 10:00

Working on GeolocMock it took me a bit to realize why my HTML could use the W3C Geolocation API in IE9 but not in my WebBrowser control in my .NET application. Eventually I realized that I was getting the wrong IE doc mode. Reading this old More IE8 Extensibility Improvements IE blog post from the IE blog I found the issue is that for app compat the WebOC picks older doc modes but an app hosting the WebOC can set a regkey to get different doc modes. The IE9 mode isn't listed in that article but I took a guess based on the values there and the decimal value 9999 gets my app IE9 mode. The following is the code I run in my application to set its regkey so that my app can get the IE9 doc mode and use the geolocation API.



        static private void UseIE9DocMode()
{
RegistryKey key = null;
try
{
key = Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Internet Explorer\\Main\\FeatureControl\\FEATURE_BROWSER_EMULATION", true);
}
catch (Exception)
{
key = Registry.CurrentUser.CreateSubKey("Software\\Microsoft\\Internet Explorer\\Main\\FeatureControl\\FEATURE_BROWSER_EMULATION");
}
key.SetValue(System.Diagnostics.Process.GetCurrentProcess().MainModule.ModuleName, 9999, RegistryValueKind.DWord);
key.Close();
}
PermalinkCommentsweboc fck ie document mode technical ie9

ILSpy - SharpDevelop Wiki

2011 Mar 28, 4:06"ILSpy is the open-source .NET assembly browser and decompiler. Development started after Red Gate announced that the free version of .NET Reflector would cease to exist by end of February 2011."PermalinkComments.net tools reflector c# development csharp dotnet technical tool

Internet Explorer team sent us cake for shipping Firefox 4 #fx4 on Twitpic

2011 Mar 22, 12:51We've now got IE9 and FF4 which means time for more cake!PermalinkCommentshumor browser webbrowser firefox ie ie9 ff4 mozilla microsoft

[whatwg] Proposal for IsSearchProviderInstalled / AddSearchProvider

2011 Feb 23, 2:17Proposal to standardize on the function to add search providers in user agents.PermalinkCommentstechnical search-provider browser webbrowser web whatwg

IE9 RC Minor Changes List - EricLaw's IEInternals - Site Home - MSDN Blogs

2011 Feb 11, 5:37PermalinkCommentsie9 development technical ie browser web eric-lawrence
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