Month: February 2011

Opening links in a new window without the target attribute

Web developers often use the attribute target="_blank" to force a link to open in a new window. However, if you use an HTML validation service to check your web pages, you know that the target attribute is not valid in strict versions of HTML and XHTML.

There is a simple way to have a link open in a new window using Javascript. You may have seen code like this:
<a href="#" onclick="window.open('http://osric.net')">osric.net web hosting</a>

That method has some serious drawbacks, though:

  • The user now sees # in the browser’s status bar instead of the actual destination URL
  • The link fails if the Javascript fails (or if the browser has Javascript disabled
  • Search engines may not follow the link

I’ve written a summary of the issue and the methods I’ve found so far that best address it. I moved it to a page outside this blog because of the Javascript examples, which were easier to include on a separate page:

How to best use Javascript to open links in a new window

More People Alive Today Than Have Ever Died

A few years ago, I ran across this quote:
“There are more people alive today than have ever died.”

As we contemplate overpopulation, a quote like that is quite thought-provoking and shocking. Could it be that the living today outnumber all of our ancestors? It’s astounding. However, I didn’t believe it. I still don’t believe it, and for good reason.
Continue reading More People Alive Today Than Have Ever Died

JSONP and Sencha Touch

I was recently trying to get a Sencha Touch demo up-and-running, but my callback functions after requests for JSON data never ran, and Firefox would throw errors along the lines of “invalid label.” I didn’t understand why–until I read more about JSONP.

JSONP prefixes your JSON response with a function name, which runs when the response is retrieved. It’s a way of handling the data without a listener.

This means that your JSONP provider needs to detect a JSONP parameter, and then wrap or “pad” the response within the specified parameter value.

For Sencha Touch, the JSON returned should be wrapped in Ext.util.JSONP.callback();. If your JSON looks like this:

{"results":[{"name":"Chris"},{"name","Harry"}]}

then your JSONP should look like this:

Ext.util.JSONP.callback({"results":[{"name":"Chris"},{"name","Harry"}]});

Not that you should hard-code that function name anywhere in your JSON output–web-based APIs and services should pick up the function from your request and wrap the JSON for you. For example, the twitter search API accepts a callback querystring parameter.

http://search.twitter.com/search.json?q=fakecriterions&callback=myCallbackFunction

would wrap the JSON response inside

myCallbackFunction();

I ignored the extra letter in the acronym at my own peril–I figured it was just a trivial variation on JSON (which it is) that wouldn’t make any difference in how it was handled (but it does).