<?php
/**
* Performs validations on HTMLPurifier_ConfigSchema_Interchange
*
* @note If you see '// handled by InterchangeBuilder', that means a
* design decision in that class would prevent this validation from
* ever being necessary. We have them anyway, however, for
* redundancy.
*/
class HTMLPurifier_ConfigSchema_Validator
{
/**
* Easy to access global objects.
*/
protected $interchange, $aliases;
/**
* Context-stack to provide easy to read error messages.
*/
protected $context = array();
/**
* HTMLPurifier_VarParser to test default's type.
*/
protected $parser;
public function __construct() {
$this->parser = new HTMLPurifier_VarParser();
}
/**
* Validates a fully-formed interchange object. Throws an
* HTMLPurifier_ConfigSchema_Exception if there's a problem.
*/
public function validate($interchange) {
$this->interchange = $interchange;
$this->aliases = array();
// PHP is a bit lax with integer <=> string conversions in
// arrays, so we don't use the identical !== comparison
foreach ($interchange->directives as $i => $directive) {
$id = $directive->id->toString();
if ($i != $id) $this->error(false, "Integrity violation: key '$i' does not match internal id '$id'");
$this->validateDirective($directive);
}
return true;
}
/**
* Validates a HTMLPurifier_ConfigSchema_Interchange_Id object.
*/
public function validateId($id) {
$id_string = $id->toString();
$this->context[] = "id '$id_string'";
if (!$id instanceof HTMLPurifier_ConfigSchema_Interchange_Id) {
// handled by InterchangeBuilder
$this->error(false, 'is not an instance of HTMLPurifier_ConfigSchema_Interchange_Id');
}
// keys are now unconstrained (we might want to narrow down to A-Za-z0-9.)
// we probably should check that it has at least one namespace
$this->with($id, 'key')
->assertNotEmpty()
->assertIsString(); // implicit assertIsString handled by InterchangeBuilder
array_pop($this->context);
}
/**
* Validates a HTMLPurifier_ConfigSchema_Interchange_Directive object.
*/
public function validateDirective($d) {
$id = $d->id->toString();
$this->context[] = "directive '$id'";
$this->validateId($d->id);
$this->with($d, 'description')
->assertNotEmpty();
// BEGIN - handled by InterchangeBuilder
$this->with($d, 'type')
->assertNotEmpty();
$this->with($d, 'typeAllowsNull')
->assertIsBool();
try {
// This also tests validity of $d->type
$this->parser->parse($d->default, $d->type, $d->typeAllowsNull);
} catch (HTMLPurifier_VarParserException $e) {
$this->error('default', 'had error: ' . $e->getMessage());
}
// END - handled by InterchangeBuilder
if (!is_null($d->allowed) || !empty($d->valueAliases)) {
// allowed and valueAliases require that we be dealing with
// strings, so check for that early.
$d_int = HTMLPurifier_VarParser::$types[$d->type];
if (!isset(HTMLPurifier_VarParser::$stringTypes[$d_int])) {
$this->error('type', 'must be a string type when used with allowed or value aliases');
}
}
$this->validateDirectiveAllowed($d);
$this->validateDirectiveValueAliases($d);
$this->validateDirectiveAliases($d);
array_pop($this->context);
}
/**
* Extra validation if $allowed member variable of
* HTMLPurifier_ConfigSchema_Interchange_Directive is defined.
*/
public function validateDirectiveAllowed($d) {
if (is_null($d->allowed)) return;
$this->with($d, 'allowed')
->assertNotEmpty()
->assertIsLookup(); // handled by InterchangeBuilder
if (is_string($d->default) && !isset($d->allowed[$d->default])) {
$this->error('default', 'must be an allowed value');
}
$this->context[] = 'allowed';
foreach ($d->allowed as $val => $x) {
if (!is_string($val)) $this->error("value $val", 'must be a string');
}
array_pop($this->context);
}
/**
* Extra validation if $valueAliases member variable of
* HTMLPurifier_ConfigSchema_Interchange_Directive is defined.
*/
public function validateDirectiveValueAliases($d) {
if (is_null($d->valueAliases)) return;
$this->with($d, 'valueAliases')
->assertIsArray(); // handled by InterchangeBuilder
$this->context[] = 'valueAliases';
foreach ($d->valueAliases as $alias => $real) {
if (!is_string($alias)) $this->error("alias $alias", 'must be a string');
if (!is_string($real)) $this->error("alias target $real from alias '$alias'", 'must be a string');
if ($alias === $real) {
$this->error("alias '$alias'", "must not be an alias to itself");
}
}
if (!is_null($d->allowed)) {
foreach ($d->valueAliases as $alias => $real) {
if (isset($d->allowed[$alias])) {
$this->error("alias '$alias'", 'must not be an allowed value');
} elseif (!isset($d->allowed[$real])) {
$this->error("alias '$alias'", 'must be an alias to an allowed value');
}
}
}
array_pop($this->context);
}
/**
* Extra validation if $aliases member variable of
* HTMLPurifier_ConfigSchema_Interchange_Directive is defined.
*/
public function validateDirectiveAliases($d) {
$this->with($d, 'aliases')
->assertIsArray(); // handled by InterchangeBuilder
$this->context[] = 'aliases';
foreach ($d->aliases as $alias) {
$this->validateId($alias);
$s = $alias->toString();
if (isset($this->interchange->directives[$s])) {
$this->error("alias '$s'", 'collides with another directive');
}
if (isset($this->aliases[$s])) {
$other_directive = $this->aliases[$s];
$this->error("alias '$s'", "collides with alias for directive '$other_directive'");
}
$this->aliases[$s] = $d->id->toString();
}
array_pop($this->context);
}
// protected helper functions
/**
* Convenience function for generating HTMLPurifier_ConfigSchema_ValidatorAtom
* for validating simple member variables of objects.
*/
protected function with($obj, $member) {
return new HTMLPurifier_ConfigSchema_ValidatorAtom($this->getFormattedContext(), $obj, $member);
}
/**
* Emits an error, providing helpful context.
*/
protected function error($target, $msg) {
if ($target !== false) $prefix = ucfirst($target) . ' in ' . $this->getFormattedContext();
else $prefix = ucfirst($this->getFormattedContext());
throw new HTMLPurifier_ConfigSchema_Exception(trim($prefix . ' ' . $msg));
}
/**
* Returns a formatted context string.
*/
protected function getFormattedContext() {
return implode(' in ', array_reverse($this->context));
}
}
// vim: et sw=4 sts=4
