I’ve been using this tool for a couple of months now, together with my colleagues at Javeline, and it has proven itself to be a power tool. If I want to show off a (supposedly) cool new thing I’m working on, or visualize this nasty bug that my co-worker promised to fix months ago, I press ‘Command+Shift+1′ automatically now; Jing captures what I’m doing in image or video quality and afterwards I can upload it to my account at Screencast.com with the push of a button. It puts the short URL to my video clip on the clipboard, so that I can paste it in into my chat conversation or blog article right away:
http://screencast.com/t/ojI7mlTF2
It just works. Nice.
It’s free, works on Windows and Mac OS X.
It’s not like I’m going to post a random thing I found useful as a Gem-of-the-day every day, but let’s stick with often.
The first gem is this one:
/**
* Execute a script in the global scope.
*
* @param {String} str
* @type {String}
*/
jpf.exec = function(str){
if (!str) return str;
var head, script;
if (window.execScript) {
window.execScript(str);
} else if (head = document.getElementsByTagName("head")[0]) {
script = document.createElement('script');
script.setAttribute('type', 'text/javascript');
script.text = str;
head.appendChild(script);
head.removeChild(script);
} else {
eval(str, window);
}
return str;
};So what does this little gem do? Well, it provides a developer the power to execute a piece of script - at runtime of course - in the global scope. For example, if your XmlHttpRequest loads the content of a .js script file (e.g. the Content-type header is set to ‘text/javascript’), ‘exec()’ will execute that script as if it were loaded with a <script> tag in the <head> section.
Dynamic script loading this feature is called. Wow. Anyway, we use it at Javeline and I found it in the Mootools library - lots of cool stuff in there by the way.
Update: Added the eval fallback with its second argument telling eval to execute the code in the scope of the window object. (This is supported by Gecko browsers only)
Update2: Changed document.head reference to document.getElementsByTagName(”head”)[0]. (Thx Mors)
