Pro PHP and jQuery by Jason Lengstorf.pdf - Computer Science ...

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CHAPTER 2 ■ COMMON JQUERY ACTIONS AND METHODS
>>> $("", { "src":"not/an/image.png", ...ot be loaded!"); }) .appendTo("body");
[ img image.png ]
The image cannot be loaded!
.scroll()
If the document is scrolled, the scroll event is fired. To bind a handler to this event, use the .scroll()
method:
$(window)
.scroll(function(){
console.log("The window was scrolled!");
});
After executing this code, scrolling the browser window will cause a message to be logged in the
console.
Additionally, calling the .scroll() method without any parameters will trigger the scroll event to
fire. After binding the preceding handler to the window, trigger the event by running the following:
$(window).scroll();
Executing this code will log the scroll event handler’s message in the console.
Handling Document Loading Events
Often, JavaScript needs to wait until the document is ready before executing any scripts. Also, when
users exit a page, sometimes it’s desirable to fire a function to ensure they meant to navigate away from
it.
.ready()
The .ready() method is used in nearly every jQuery script as a safeguard against the script executing too
early and, therefore, not performing properly. This method waits for the DOM to be ready for
manipulation before firing its handler.
Common practice is to make the entire script a callback function to be fired by the .ready()
handler:
$(document).ready(function(){
// All jQuery functionality here
});
Additionally, the .ready() method accepts a parameter to use as an alias for the jQuery function.
This allows you to write failsafe jQuery scripts that will work as expected even if the $ alias is given back