Friday, March 29, 2013
Wednesday, March 20, 2013
Voyager 1 left Solar system for good...
Looks like it's official now - Voyager 1 crossed the edge of Solar system! For somebody who still remembers Carl Sagan's "Cosmos" that's exciting news. I wonder how long it will keep sending...
Go Voyager Go!
Go Voyager Go!
Wednesday, March 6, 2013
This and that in JavaScript
This and that in JavaScript - or self as I've seen it, is just a workaround for the fact that in JavaScript, inner function "this" is not behaving like "this" from the outer function, it points to the window object.. Yes, it's a bug, and it will be fixed in ECMA5.
Closure mechanism - an inner function always has access to the vars and parameters of its outer function, even after the outer function has returned.
Something like this:
To preserve outer function "this", putting "this" into local variable ("that" or "self") will allow transfer of variable from outer function to be used, by using closures.
Closure mechanism - an inner function always has access to the vars and parameters of its outer function, even after the outer function has returned.
Something like this:
<!DOCTYPE html><html lang="en"><head></head> <body><script>var myObject = { myProperty:'Some text here', myMethod:function() { var that = this; //reference to myObject in myMethod scope var innerFunction function() { // inner one console.log(that.myProperty); //logs 'Some text here' console.log(this); // logs window object to show what will happen if we don't store this into that }(); }}myObject.myMethod(); // invoke myMethod</script></body></html>Debugging client side script
I was trying to debug client side code and was getting those "Breakpoint will not be hit" messages. Turn out that to allow debugging of the client side script, you need to Attach debugger to the process but before you actually do that, click Select button on the top of the list of processes. If it on automatic, change it to Script.
That functionality goes back to Visual Studio 2008 and it's still there in VS 2012.
There are other ways too - debugger; in javascript code, or using Client debugging in IE or Firefox (or Chrome), but it's nice not to have to do anything extra but use VS when you want to attach to the process anyways.
That functionality goes back to Visual Studio 2008 and it's still there in VS 2012.
There are other ways too - debugger; in javascript code, or using Client debugging in IE or Firefox (or Chrome), but it's nice not to have to do anything extra but use VS when you want to attach to the process anyways.
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