Drupal 6 JavaScript and jQuery - Ebook-Cours.com

In this case, we have a string object, not a jQuery object. Sure, we could continue
chaining, but we could only call functions of the string object. For instance, the
following would work just fine:
$('h1').text().substring(0,1);
The text() function returns a string, and substring() is a member function of
a string object. However, we could not do this:
$('h1').text().css('color','red');
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Chapter 3
This would generate an error looking something like this: TypeError: $("h1").text().
css is not a function. That happens because a string object does not have a
css() function.
At this point, the important things to understand about jQuery are:
•
How queries can be composed from CSS selectors
• How $() and jQuery() return jQuery objects (that often wrap lists of
elements from the document)
•
That jQuery function calls are often chained together to produce longer lines
that do more
We will pick up more about jQuery as we proceed.
Feeling comfortable with the basic concepts of jQuery? Now it's time to get back
to Drupal. We will be making use of jQuery to build Drupal-centric JavaScript.
Using jQuery in Drupal
So far, we have seen just a few lines of jQuery code. But, our examples have been
independent of Drupal. How can we use jQuery inside of Drupal?
The answer is simple. If we write our JavaScript "the Drupal way", then Drupal will
make it very easy to use jQuery. Here's what I mean.
How do we include JavaScript files in Drupal themes? By using the scripts[]
directive in the theme's .info file. And if you're a PHP programmer, you can use
the drupal_add_js() function in either a theme or a module.
If you use either of these means, then Drupal will automatically include the basic
JavaScript libraries, including drupal.js and jquery.js. That's right. Drupal not
only includes jQuery in its core distribution, but automatically includes it for you.
This material is copyright and is licensed for the sole use by Richard Ostheimer on 18th June 2009
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