code.commongroove.com » JavaScript

JavaScript: Extending String to Have startsWith and endWith Functions

Greg — Fri, 09 Sep 2011 13:13:55 +0000

Here’s two prototype functions you can add to your JavaScript to give you “startsWith” and “endsWith” functions:

if (!String.prototype.startsWith) {
String.prototype.startsWith = function (str) {
return this.slice(0, str.length) == str;
};
}

if (!String.prototype.endsWith) {
String.prototype.endsWith = function(str) {
return this.slice(-str.length) == str;
};
}

Hope this helps!

jQuery: Global AJAX Error Handler

Greg — Sun, 24 Apr 2011 23:49:46 +0000

Here’s a quick and dirty way to handle AJAX errors globally if you are using jQuery:

$(document).ready(function () {
$.ajaxSetup({
error: function (x, e) {
if (x.status == 0) {
alert('Network error');
} else if (x.status == 404) {
alert('404 Page not found');
} else if (x.status == 500) {
// assume msft brings error page back with a useful title
var titleMatch = /(.*?)<\/title>/.exec(x.responseText);
var titleString = titleMatch ? titleMatch[1] : '';
alert('Oops!\n\n500 Internal Server Error\n\n' + titleString);
} else if (e == 'parsererror') {
alert('Error.\nParsing JSON Request failed.');
} else if (e == 'timeout') {
alert('Request Time out.');
} else {
alert('Unkown error: ' + x.status + ' ' + x.statusText + '\n\n' + x.responseText);
}
}
});
});

Now, of course you most likely wouldn’t want to just use an alert() call to notify your users, but hopefully this helps get you started. Also, using a global handler isn’t always the best option; look into using the jQuery .ajaxError() method of handling errors for specific AJAX calls as well.

JavaScript: Quickly Trim the Last Character from a String

Greg — Wed, 06 Apr 2011 17:31:01 +0000

When developing web applications, you undoubtedly have wanted to remove the last character from a string (such as a URL or application path) in your JavaScript code.

Here’s a quick way to get it done using the JavaScript function slice():

var applicationPath = '/my/application/path/';
var removedLastCharacter = applicationPath.slice(0, -1);

JavaScript, UTF-8 Encoding: escape() vs. encodeURIComponent()

Greg — Thu, 06 Aug 2009 23:07:00 +0000

ASP.Net web applications default to UTF-8 encoding. Now, if you are using JavaScript to create or change URLs, you might run into an issue with the way the function “escape()” encodes characters if you are handling the decoding in your code behind via Request.QueryString.

To avoid ending up with “unkown” characters in your resultant string, use the JavaScript function “encodeURIComponent()” instead. This should correctly encode your URLs for UTF-8.

Sys.WebForms.PageRequestManagerServerErrorException in FireFox with MSFT Ajax

Greg — Thu, 11 Dec 2008 02:18:10 +0000

If you encounter this error while navigating away from an AJAX-enabled page with a non-IE browser, you can silence it with the following JavaScript:

if (!document.all) //non-ie
{
window.onbeforeunload = function() {
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(ignoreOnEndRequest);
}
}

function ignoreOnEndRequest(sender, e) {
err = e.get_error();
if (err) {
if (err.name == "Sys.WebForms.PageRequestManagerServerErrorException") {
e.set_errorHandled(true);
}
}
}

Hope it works for you!

Using the PageRequestManager in ASP.Net AJAX (ATLAS)

Greg — Thu, 27 Sep 2007 00:58:57 +0000

In your java script::

var postBackElem;
Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(BeginRequestHandler);
Sys.WebForms.PageRequestManager.getInstance().add_pageLoaded(PageLoadedHandler);
function BeginRequestHandler(sender, args)
{
postBackElem = args.get_postBackElement();
}
function PageLoadedHandler(sender, args)
{
var c = 'panels created: ';
var u = 'panels updated: ';

for(var i=0;i
c += args.get_panelsCreated()[i].id + ', ';
}

for(var i=0;i
u += args.get_panelsUpdated()[i].id + ', ';
}

alert(c);
alert(u);
}

FireFox caches JavaScript state

Greg — Thu, 27 Sep 2007 00:57:19 +0000

Firefox uses in memory caching for JavaScript and can cause strange errors in your MSFT ASP.NET Ajax applications.

Try adding this to your load event to prevent those errors:

if (Request.Browser.MSDomVersion.Major == 0) // Non IE Browser?)
{
Response.Cache.SetNoStore(); // No client side cashing for non IE browsers
}

Automatically close a window in FireFox

Greg — Thu, 27 Sep 2007 00:54:48 +0000

You may run into an issue trying to close a created window in FireFox, this javascript usually does the trick on your close link:

window.open(’java script:window.close();’,’_self’,’’);