1<?php
2
3/**
4 * Processes an entire attribute array for corrections needing multiple values.
5 *
6 * Occasionally, a certain attribute will need to be removed and popped onto
7 * another value.  Instead of creating a complex return syntax for
8 * HTMLPurifier_AttrDef, we just pass the whole attribute array to a
9 * specialized object and have that do the special work.  That is the
10 * family of HTMLPurifier_AttrTransform.
11 *
12 * An attribute transformation can be assigned to run before or after
13 * HTMLPurifier_AttrDef validation.  See HTMLPurifier_HTMLDefinition for
14 * more details.
15 */
16
17abstract class HTMLPurifier_AttrTransform
18{
19
20    /**
21     * Abstract: makes changes to the attributes dependent on multiple values.
22     *
23     * @param array $attr Assoc array of attributes, usually from
24     *              HTMLPurifier_Token_Tag::$attr
25     * @param HTMLPurifier_Config $config Mandatory HTMLPurifier_Config object.
26     * @param HTMLPurifier_Context $context Mandatory HTMLPurifier_Context object
27     * @return array Processed attribute array.
28     */
29    abstract public function transform($attr, $config, $context);
30
31    /**
32     * Prepends CSS properties to the style attribute, creating the
33     * attribute if it doesn't exist.
34     * @param array &$attr Attribute array to process (passed by reference)
35     * @param string $css CSS to prepend
36     */
37    public function prependCSS(&$attr, $css)
38    {
39        $attr['style'] = isset($attr['style']) ? $attr['style'] : '';
40        $attr['style'] = $css . $attr['style'];
41    }
42
43    /**
44     * Retrieves and removes an attribute
45     * @param array &$attr Attribute array to process (passed by reference)
46     * @param mixed $key Key of attribute to confiscate
47     * @return mixed
48     */
49    public function confiscateAttr(&$attr, $key)
50    {
51        if (!isset($attr[$key])) {
52            return null;
53        }
54        $value = $attr[$key];
55        unset($attr[$key]);
56        return $value;
57    }
58}
59
60// vim: et sw=4 sts=4
61