configschema.php

很棒的在线教学系统

<?php

require_once 'HTMLPurifier/Error.php';
require_once 'HTMLPurifier/ConfigDef.php';
require_once 'HTMLPurifier/ConfigDef/Namespace.php';
require_once 'HTMLPurifier/ConfigDef/Directive.php';
require_once 'HTMLPurifier/ConfigDef/DirectiveAlias.php';

if (!defined('HTMLPURIFIER_SCHEMA_STRICT')) define('HTMLPURIFIER_SCHEMA_STRICT', false);

/**
 * Configuration definition, defines directives and their defaults.
 * @note If you update this, please update Printer_ConfigForm
 * @todo The ability to define things multiple times is confusing and should
 *       be factored out to its own function named registerDependency() or 
 *       addNote(), where only the namespace.name and an extra descriptions
 *       documenting the nature of the dependency are needed.  Since it's
 *       possible that the dependency is registered before the configuration
 *       is defined, deferring it to some sort of cache until it actually
 *       gets defined would be wise, keeping it opaque until it does get
 *       defined. We could add a finalize() method which would cause it to
 *       error out if we get a dangling dependency.  It's difficult, however,
 *       to know whether or not it's a dependency, or a codependency, that is
 *       neither of them fully depends on it. Where does the configuration go
 *       then?  This could be partially resolved by allowing blanket definitions
 *       and then splitting them up into finer-grained versions, however, there
 *       might be implementation difficulties in ini files regarding order of
 *       execution.
 */
class HTMLPurifier_ConfigSchema {
    
    /**
     * Defaults of the directives and namespaces.
     * @note This shares the exact same structure as HTMLPurifier_Config::$conf
     */
    var $defaults = array();
    
    /**
     * Definition of the directives.
     */
    var $info = array();
    
    /**
     * Definition of namespaces.
     */
    var $info_namespace = array();
    
    /**
     * Lookup table of allowed types.
     */
    var $types = array(
        'string'    => 'String',
        'istring'   => 'Case-insensitive string',
        'text'      => 'Text',
        'itext'      => 'Case-insensitive text',
        'int'       => 'Integer',
        'float'     => 'Float',
        'bool'      => 'Boolean',
        'lookup'    => 'Lookup array',
        'list'      => 'Array list',
        'hash'      => 'Associative array',
        'mixed'     => 'Mixed'
    );
    
    /**
     * Initializes the default namespaces.
     */
    function initialize() {
        $this->defineNamespace('Core', 'Core features that are always available.');
        $this->defineNamespace('Attr', 'Features regarding attribute validation.');
        $this->defineNamespace('URI', 'Features regarding Uniform Resource Identifiers.');
        $this->defineNamespace('HTML', 'Configuration regarding allowed HTML.');
        $this->defineNamespace('CSS', 'Configuration regarding allowed CSS.');
        $this->defineNamespace('AutoFormat', 'Configuration for activating auto-formatting functionality (also known as <code>Injector</code>s)');
        $this->defineNamespace('AutoFormatParam', 'Configuration for customizing auto-formatting functionality');
        $this->defineNamespace('Output', 'Configuration relating to the generation of (X)HTML.');
        $this->defineNamespace('Cache', 'Configuration for DefinitionCache and related subclasses.');
        $this->defineNamespace('Test', 'Developer testing configuration for our unit tests.');
    }
    
    /**
     * Retrieves an instance of the application-wide configuration definition.
     * @static
     */
    function &instance($prototype = null) {
        static $instance;
        if ($prototype !== null) {
            $instance = $prototype;
        } elseif ($instance === null || $prototype === true) {
            $instance = new HTMLPurifier_ConfigSchema();
            $instance->initialize();
        }
        return $instance;
    }
    
    /**
     * Defines a directive for configuration
     * @static
     * @warning Will fail of directive's namespace is defined
     * @param $namespace Namespace the directive is in
     * @param $name Key of directive
     * @param $default Default value of directive
     * @param $type Allowed type of the directive. See
     *      HTMLPurifier_DirectiveDef::$type for allowed values
     * @param $description Description of directive for documentation
     */
    function define($namespace, $name, $default, $type, $description) {
        $def =& HTMLPurifier_ConfigSchema::instance();
        
        // basic sanity checks
        if (HTMLPURIFIER_SCHEMA_STRICT) {
            if (!isset($def->info[$namespace])) {
                trigger_error('Cannot define directive for undefined namespace',
                    E_USER_ERROR);
                return;
            }
            if (!ctype_alnum($name)) {
                trigger_error('Directive name must be alphanumeric',
                    E_USER_ERROR);
                return;
            }
            if (empty($description)) {
                trigger_error('Description must be non-empty',
                    E_USER_ERROR);
                return;
            }
        }
        
        if (isset($def->info[$namespace][$name])) {
            // already defined
            if (
                $def->info[$namespace][$name]->type !== $type ||
                $def->defaults[$namespace][$name]   !== $default
            ) {
                trigger_error('Inconsistent default or type, cannot redefine');
                return;
            }
        } else {
            // needs defining
            
            // process modifiers (OPTIMIZE!)
            $type_values = explode('/', $type, 2);
            $type = $type_values[0];
            $modifier = isset($type_values[1]) ? $type_values[1] : false;
            $allow_null = ($modifier === 'null');
            
            if (HTMLPURIFIER_SCHEMA_STRICT) {
                if (!isset($def->types[$type])) {
                    trigger_error('Invalid type for configuration directive',
                        E_USER_ERROR);
                    return;
                }
                $default = $def->validate($default, $type, $allow_null);
                if ($def->isError($default)) {
                    trigger_error('Default value does not match directive type',
                        E_USER_ERROR);
                    return;
                }
            }
            
            $def->info[$namespace][$name] =
                new HTMLPurifier_ConfigDef_Directive();
            $def->info[$namespace][$name]->type = $type;
            $def->info[$namespace][$name]->allow_null = $allow_null;
            $def->defaults[$namespace][$name]   = $default;
        }
        if (!HTMLPURIFIER_SCHEMA_STRICT) return;
        $backtrace = debug_backtrace();
        $file = $def->mungeFilename($backtrace[0]['file']);
        $line = $backtrace[0]['line'];
        $def->info[$namespace][$name]->addDescription($file,$line,$description);
    }
    
    /**
     * Defines a namespace for directives to be put into.
     * @static
     * @param $namespace Namespace's name
     * @param $description Description of the namespace
     */
    function defineNamespace($namespace, $description) {
        $def =& HTMLPurifier_ConfigSchema::instance();
        if (HTMLPURIFIER_SCHEMA_STRICT) {
            if (isset($def->info[$namespace])) {
                trigger_error('Cannot redefine namespace', E_USER_ERROR);
                return;
            }
            if (!ctype_alnum($namespace)) {
                trigger_error('Namespace name must be alphanumeric',
                    E_USER_ERROR);
                return;
            }
            if (empty($description)) {
                trigger_error('Description must be non-empty',
                    E_USER_ERROR);
                return;
            }
        }
        $def->info[$namespace] = array();
        $def->info_namespace[$namespace] = new HTMLPurifier_ConfigDef_Namespace();
        $def->info_namespace[$namespace]->description = $description;
        $def->defaults[$namespace] = array();
    }
    
    /**
     * Defines a directive value alias.
     * 
     * Directive value aliases are convenient for developers because it lets
     * them set a directive to several values and get the same result.
     * @static
     * @param $namespace Directive's namespace
     * @param $name Name of Directive
     * @param $alias Name of aliased value
     * @param $real Value aliased value will be converted into
     */
    function defineValueAliases($namespace, $name, $aliases) {
        $def =& HTMLPurifier_ConfigSchema::instance();
        if (HTMLPURIFIER_SCHEMA_STRICT && !isset($def->info[$namespace][$name])) {
            trigger_error('Cannot set value alias for non-existant directive',
                E_USER_ERROR);