Use onContentPrepare to change Article text in a Joomla 2.5 plugin

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When writing a Joomla 2.5 content plugin, you can use the onContentPrepare event to change the text within an Article. While other events, such as onContentAfterTitle, are useful for adding text, onContentPrepare is best for modifying the text entirely.

In this plugin development tutorial, we’ll show you an example of how to change text using onContentPrepare.

Accessing Article Text using $row->text

Before you can manipulate any of the article’s text, you must first know where it is stored. In functions declared like the following:

public function onContentPrepare($context, &$row, &$params, $page = 0)

The $row object will hold the article’s text (and introtext). You can use the following to view the content:

$row->text

Modifying Article Content

To change article text, you can change the $row->text variable. Look at the following code:

public function onContentPrepare($context, &$row, &$params, $page = 0)
{
    $row->text = str_replace("a","A",$row->text);
}

In the above onContentPrepare function, we are replacing every lower-case a with a capital A. While this is not the best real world example, it does show you how to change the text of an article. As you can see in the screenshot below, all of the letter a’s have been changed to A.