Creating a Customized Conversion List - PHP

Thestrtr()function converts all characters in a string to their corresponding match found in a predefined array. Its prototype follows:

string strtr(string str, array replacements)

This example converts the deprecated bold (<b>) character to its XHTML equivalent:

<?php
    $table = array("<b>" => "<strong>", "</b>" => "</strong>");
    $html = "<b>Today In PHP-Powered News</b>";
    echo strtr($html, $table);
?>

This returns the following:

--------------------------------------------
<strong>Today In PHP-Powered News</strong>
--------------------------------------------

Converting HTML to Plain Text

You may sometimes need to convert an HTML file to plain text. You can do so using thestrip_tags()function, which removes all HTML and PHP tags from a string, leaving only the text entities. Its prototype follows:

string strip_tags(string str [, string allowable_tags])

The optionalallowable_tagsparameter allows you to specify which tags you would like to be skipped during this process. This example usesstrip_tags()to delete all HTML tags from a string:

<?php
    $input = "Email <a href='spammer@example.com'>spammer@example.com</a>";
    echo strip_tags($input);
?>

This returns the following:

--------------------------------------------
Email spammer@example.com
--------------------------------------------

The following sample strips all tags except the<a>tag:

<?php
    $input = "This <a href='http://www.example.com/'>example</a>
              is <b>awesome</b>!";
    echo strip_tags($input, "<a>");
?>

This returns the following:

--------------------------------------------
This <a href='http://www.example.com/'>example</a> is awesome!
--------------------------------------------

Note  Another function that behaves like strip_tags()isfgetss(). This function is described in Chapter 10.