Drupal 7 Module Development

Chapter 10
There are three ways variables can be passed through Drupal.t() depending on the
first character of the variable:
• Variables beginning with a ! are inserted as is, with no modification.
• When a variable begins with an @ symbol the value is passed through
Drupal.checkPlain(), a function that converts the string to plain text.
HTML markup is converted to text that can be displayed.
• % at the beginning of a variable will cause the variable to be passed through
Drupal.checkPlain() and Drupal.theme('placeholder').
Behaviors
If you're familiar with writing jQuery, you know that the code you want to execute
as early as possible in a page load is wrapped in something like the following:
$(document).ready(function() {
...
});
When the document is ready the code wrapped inside this function will be executed.
This is a common pattern for jQuery-based JavaScript. Drupal provides a system
that wraps and extends this concept called behaviors. Behaviors are attached and
detached from a section of content. The most common usage is to attach a behavior
to an entire page.
Rewriting our Hello World example seen previously to use behaviors would look
as follows:
(function($) {
Drupal.theme.prototype.hello = function(text) {
return '' + Drupal.t('Hello @city', {'@city': text}) +
'';
}
Drupal.behaviors.helloWorld = {
attach: function(context, settings) {
$('#hello-world', context).html(Drupal.theme('hello',
'Chicago'));
}
}
})(jQuery);
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