/home/kueuepay/public_html/vendor/ezyang/htmlpurifier/library/HTMLPurifier/ChildDef/Required.php
<?php

/**
 * Definition that allows a set of elements, but disallows empty children.
 */
class HTMLPurifier_ChildDef_Required extends HTMLPurifier_ChildDef
{
    /**
     * Lookup table of allowed elements.
     * @type array
     */
    public $elements = array();

    /**
     * Whether or not the last passed node was all whitespace.
     * @type bool
     */
    protected $whitespace = false;

    /**
     * @param array|string $elements List of allowed element names (lowercase).
     */
    public function __construct($elements)
    {
        if (is_string($elements)) {
            $elements = str_replace(' ', '', $elements);
            $elements = explode('|', $elements);
        }
        $keys = array_keys($elements);
        if ($keys == array_keys($keys)) {
            $elements = array_flip($elements);
            foreach ($elements as $i => $x) {
                $elements[$i] = true;
                if (empty($i)) {
                    unset($elements[$i]);
                } // remove blank
            }
        }
        $this->elements = $elements;
    }

    /**
     * @type bool
     */
    public $allow_empty = false;

    /**
     * @type string
     */
    public $type = 'required';

    /**
     * @param array $children
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return array
     */
    public function validateChildren($children, $config, $context)
    {
        // Flag for subclasses
        $this->whitespace = false;

        // if there are no tokens, delete parent node
        if (empty($children)) {
            return false;
        }

        // the new set of children
        $result = array();

        // whether or not parsed character data is allowed
        // this controls whether or not we silently drop a tag
        // or generate escaped HTML from it
        $pcdata_allowed = isset($this->elements['#PCDATA']);

        // a little sanity check to make sure it's not ALL whitespace
        $all_whitespace = true;

        $stack = array_reverse($children);
        while (!empty($stack)) {
            $node = array_pop($stack);
            if (!empty($node->is_whitespace)) {
                $result[] = $node;
                continue;
            }
            $all_whitespace = false; // phew, we're not talking about whitespace

            if (!isset($this->elements[$node->name])) {
                // special case text
                // XXX One of these ought to be redundant or something
                if ($pcdata_allowed && $node instanceof HTMLPurifier_Node_Text) {
                    $result[] = $node;
                    continue;
                }
                // spill the child contents in
                // ToDo: Make configurable
                if ($node instanceof HTMLPurifier_Node_Element) {
                    for ($i = count($node->children) - 1; $i >= 0; $i--) {
                        $stack[] = $node->children[$i];
                    }
                    continue;
                }
                continue;
            }
            $result[] = $node;
        }
        if (empty($result)) {
            return false;
        }
        if ($all_whitespace) {
            $this->whitespace = true;
            return false;
        }
        return $result;
    }
}

// vim: et sw=4 sts=4
Best Practice

Best Practices

To ensure a smooth integration process and optimal performance, follow these best practices:

  1. Use secure HTTPS connections for all API requests.
  2. Implement robust error handling to handle potential issues gracefully.
  3. Regularly update your integration to stay current with any API changes or enhancements.