Drupal 6 JavaScript and jQuery - Ebook-Cours.com

jQuery: Do More with Drupal
The highest variable will store the size of the highest node. By default, we set it to
100 pixels.
Next, we make use of another jQuery feature. Along with the rest of the jQuery
goodies, there are a handful of basic list-traversing functions. One of these is the
each() function, which iterates through each item in the list of nodes wrapped
by a jQuery object. On each object, it executes the function passed into the each
() function.
There are actually two jQuery each() functions: One that iterates
through the contents of a jQuery object, and one that iterates through
any list-like object. The list-iterating version is called on the main jQuery
object like this: jQuery.each(myList, function () {}).
So this version of each() takes one argument—a function object.
In our case, we are going to supply the each() function with an anonymous function
that will do the height comparison:
stickies.each(function () {
var stickyHeight = $(this).height();
if(stickyHeight > highest) {
highest = stickyHeight;
}
});
When that anonymous function is executed, the this variable is set to the current list
item. In our case, this will contain the current DOM element in the list of stickies.
This method of formatting inline anonymous functions is conventional,
and you will see the same formatting throughout jQuery and Drupal.
It is important to note that this is a DOM element object, not a jQuery object.
We want to find the height of that object, but the easiest way to get the height of
an element is to use the jQuery library. So in the second line, we pass this into
$() to get a new jQuery object, Then we use jQuery's height() function to find
out the element's height. This is all packed into the line that reads: var
stickyHeight = $(this).height().
While the first two lines of this code sample are complex, the next part
is straightforward:
if(stickyHeight > highest) {
highest = stickyHeight;
}
[ 82 ]
This material is copyright and is licensed for the sole use by Richard Ostheimer on 18th June 2009
2205 hilda ave., , missoula, , 59801