Proyectos de Subversion Moodle

<?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

{

    /**

     * @type HTMLPurifier_ConfigSchema_Interchange

     */

    protected $interchange;

    /**

     * @type array

     */

    protected $aliases;

    /**

     * Context-stack to provide easy to read error messages.

     * @type array

     */

    protected $context = array();

    /**

     * to test default's type.

     * @type HTMLPurifier_VarParser

     */

    protected $parser;

    public function __construct()

    {

        $this->parser = new HTMLPurifier_VarParser();

    }

    /**

     * Validates a fully-formed interchange object.

     * @param HTMLPurifier_ConfigSchema_Interchange $interchange

     * @return bool

     */

    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.

     * @param HTMLPurifier_ConfigSchema_Interchange_Id $id

     */

    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.

     * @param HTMLPurifier_ConfigSchema_Interchange_Directive $d

     */

    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.

     * @param HTMLPurifier_ConfigSchema_Interchange_Directive $d

     */

    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.

     * @param HTMLPurifier_ConfigSchema_Interchange_Directive $d

     */

    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.

     * @param HTMLPurifier_ConfigSchema_Interchange_Directive $d

     */

    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.

     * @param $obj

     * @param $member

     * @return HTMLPurifier_ConfigSchema_ValidatorAtom

     */

    protected function with($obj, $member)

    {

        return new HTMLPurifier_ConfigSchema_ValidatorAtom($this->getFormattedContext(), $obj, $member);

    }

    /**

     * Emits an error, providing helpful context.

     * @throws HTMLPurifier_ConfigSchema_Exception

     */

    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.

     * @return string

     */

    protected function getFormattedContext()

    {

        return implode(' in ', array_reverse($this->context));

    }

}

// vim: et sw=4 sts=4