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htmlpurifier/library/HTMLPurifier/ConfigSchema.php
Edward Z. Yang b93892a3b6 [1.1.1] Update documentation and TODO.
git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@436 48356398-32a2-884e-a903-53898d9a118a
2006-09-17 21:59:40 +00:00

337 lines
12 KiB
PHP

<?php
/**
* Configuration definition, defines directives and their defaults.
* @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',
'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.');
$this->defineNamespace('Test', 'Developer testing configuration for our unit tests.');
}
/**
* Retrieves an instance of the application-wide configuration definition.
*/
function &instance($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
* @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
) {
$def =& HTMLPurifier_ConfigSchema::instance();
if (!isset($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 (isset($def->info[$namespace][$name])) {
if (
$def->info[$namespace][$name]->type !== $type ||
$def->defaults[$namespace][$name] !== $default
) {
trigger_error('Inconsistent default or type, cannot redefine');
return;
}
} else {
if (!isset($def->types[$type])) {
trigger_error('Invalid type for configuration directive',
E_USER_ERROR);
return;
}
if ($def->validate($default, $type) === null) {
trigger_error('Default value does not match directive type',
E_USER_ERROR);
return;
}
$def->info[$namespace][$name] =
new HTMLPurifier_ConfigEntity_Directive();
$def->info[$namespace][$name]->type = $type;
$def->defaults[$namespace][$name] = $default;
}
$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.
* @param $namespace Namespace's name
* @param $description Description of the namespace
*/
function defineNamespace($namespace, $description) {
$def =& HTMLPurifier_ConfigSchema::instance();
if (isset($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;
}
$def->info[$namespace] = array();
$def->info_namespace[$namespace] = new HTMLPurifier_ConfigEntity_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.
* @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) {
$def =& HTMLPurifier_ConfigSchema::instance();
if (!isset($def->info[$namespace][$name])) {
trigger_error('Cannot set value alias for non-existant directive',
E_USER_ERROR);
return;
}
foreach ($aliases as $alias => $real) {
if (!$def->info[$namespace][$name] !== true &&
!isset($def->info[$namespace][$name]->allowed[$real])
) {
trigger_error('Cannot define alias to value that is not allowed',
E_USER_ERROR);
return;
}
if (isset($def->info[$namespace][$name]->allowed[$alias])) {
trigger_error('Cannot define alias over allowed value',
E_USER_ERROR);
return;
}
$def->info[$namespace][$name]->aliases[$alias] = $real;
}
}
/**
* Defines a set of allowed values for a directive.
* @param $namespace Namespace of directive
* @param $name Name of directive
* @param $allowed_values Arraylist of allowed values
*/
function defineAllowedValues($namespace, $name, $allowed_values) {
$def =& HTMLPurifier_ConfigSchema::instance();
if (!isset($def->info[$namespace][$name])) {
trigger_error('Cannot define allowed values for undefined directive',
E_USER_ERROR);
return;
}
if ($def->info[$namespace][$name]->allowed === true) {
$def->info[$namespace][$name]->allowed = array();
}
foreach ($allowed_values as $value) {
$def->info[$namespace][$name]->allowed[$value] = true;
}
}
/**
* Validate a variable according to type. Return null if invalid.
*/
function validate($var, $type) {
if (!isset($this->types[$type])) {
trigger_error('Invalid type', E_USER_ERROR);
return;
}
switch ($type) {
case 'mixed':
return $var;
case 'istring':
case 'string':
if (!is_string($var)) return;
if ($type === 'istring') $var = strtolower($var);
return $var;
case 'int':
if (is_string($var) && ctype_digit($var)) $var = (int) $var;
elseif (!is_int($var)) return;
return $var;
case 'float':
if (is_string($var) && is_numeric($var)) $var = (float) $var;
elseif (!is_float($var)) return;
return $var;
case 'bool':
if (is_int($var) && ($var === 0 || $var === 1)) {
$var = (bool) $var;
} elseif (!is_bool($var)) return;
return $var;
case 'list':
case 'hash':
case 'lookup':
if (!is_array($var)) return;
$keys = array_keys($var);
if ($keys === array_keys($keys)) {
if ($type == 'list') return $var;
elseif ($type == 'lookup') {
$new = array();
foreach ($var as $key) {
$new[$key] = true;
}
return $new;
} else return;
}
if ($type === 'lookup') {
foreach ($var as $key => $value) {
$var[$key] = true;
}
}
return $var;
}
}
function mungeFilename($filename) {
$offset = strrpos($filename, 'HTMLPurifier');
$filename = substr($filename, $offset);
$filename = str_replace('\\', '/', $filename);
return $filename;
}
}
/**
* Base class for configuration entity
*/
class HTMLPurifier_ConfigEntity {}
/**
* Structure object describing of a namespace
*/
class HTMLPurifier_ConfigEntity_Namespace extends HTMLPurifier_ConfigEntity {
/**
* String description of what kinds of directives go in this namespace.
*/
var $description;
}
/**
* Structure object containing definition of a directive.
* @note This structure does not contain default values
*/
class HTMLPurifier_ConfigEntity_Directive extends HTMLPurifier_ConfigEntity
{
/**
* Hash of value aliases, i.e. values that are equivalent.
*/
var $aliases = array();
/**
* Lookup table of allowed values of the element, bool true if all allowed.
*/
var $allowed = true;
/**
* Allowed type of the directive. Values are:
* - string
* - istring (case insensitive string)
* - int
* - float
* - bool
* - lookup (array of value => true)
* - list (regular numbered index array)
* - hash (array of key => value)
* - mixed (anything goes)
*/
var $type = 'mixed';
/**
* Plaintext descriptions of the configuration entity is. Organized by
* file and line number, so multiple descriptions are allowed.
*/
var $descriptions = array();
/**
* Adds a description to the array
*/
function addDescription($file, $line, $description) {
if (!isset($this->descriptions[$file])) $this->descriptions[$file] = array();
$this->descriptions[$file][$line] = $description;
}
}
?>