<?php 
 
/** 
 * Validates the attributes of a token. Doesn't manage required attributes 
 * very well. The only reason we factored this out was because RemoveForeignElements 
 * also needed it besides ValidateAttributes. 
 */ 
class HTMLPurifier_AttrValidator 
{ 
 
    /** 
     * Validates the attributes of a token, returning a modified token 
     * that has valid tokens 
     * @param $token Reference to token to validate. We require a reference 
     *     because the operation this class performs on the token are 
     *     not atomic, so the context CurrentToken to be updated 
     *     throughout 
     * @param $config Instance of HTMLPurifier_Config 
     * @param $context Instance of HTMLPurifier_Context 
     */ 
    public function validateToken(&$token, &$config, $context) { 
 
        $definition = $config->getHTMLDefinition(); 
        $e =& $context->get('ErrorCollector', true); 
 
        // initialize IDAccumulator if necessary 
        $ok =& $context->get('IDAccumulator', true); 
        if (!$ok) { 
            $id_accumulator = HTMLPurifier_IDAccumulator::build($config, $context); 
            $context->register('IDAccumulator', $id_accumulator); 
        } 
 
        // initialize CurrentToken if necessary 
        $current_token =& $context->get('CurrentToken', true); 
        if (!$current_token) $context->register('CurrentToken', $token); 
 
        if ( 
            !$token instanceof HTMLPurifier_Token_Start && 
            !$token instanceof HTMLPurifier_Token_Empty 
        ) return $token; 
 
        // create alias to global definition array, see also $defs 
        // DEFINITION CALL 
        $d_defs = $definition->info_global_attr; 
 
        // don't update token until the very end, to ensure an atomic update 
        $attr = $token->attr; 
 
        // do global transformations (pre) 
        // nothing currently utilizes this 
        foreach ($definition->info_attr_transform_pre as $transform) { 
            $attr = $transform->transform($o = $attr, $config, $context); 
            if ($e) { 
                if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); 
            } 
        } 
 
        // do local transformations only applicable to this element (pre) 
        // ex. <p align="right"> to <p style="text-align:right;"> 
        foreach ($definition->info[$token->name]->attr_transform_pre as $transform) { 
            $attr = $transform->transform($o = $attr, $config, $context); 
            if ($e) { 
                if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); 
            } 
        } 
 
        // create alias to this element's attribute definition array, see 
        // also $d_defs (global attribute definition array) 
        // DEFINITION CALL 
        $defs = $definition->info[$token->name]->attr; 
 
        $attr_key = false; 
        $context->register('CurrentAttr', $attr_key); 
 
        // iterate through all the attribute keypairs 
        // Watch out for name collisions: $key has previously been used 
        foreach ($attr as $attr_key => $value) { 
 
            // call the definition 
            if ( isset($defs[$attr_key]) ) { 
                // there is a local definition defined 
                if ($defs[$attr_key] === false) { 
                    // We've explicitly been told not to allow this element. 
                    // This is usually when there's a global definition 
                    // that must be overridden. 
                    // Theoretically speaking, we could have a 
                    // AttrDef_DenyAll, but this is faster! 
                    $result = false; 
                } else { 
                    // validate according to the element's definition 
                    $result = $defs[$attr_key]->validate( 
                                    $value, $config, $context 
                               ); 
                } 
            } elseif ( isset($d_defs[$attr_key]) ) { 
                // there is a global definition defined, validate according 
                // to the global definition 
                $result = $d_defs[$attr_key]->validate( 
                                $value, $config, $context 
                           ); 
            } else { 
                // system never heard of the attribute? DELETE! 
                $result = false; 
            } 
 
            // put the results into effect 
            if ($result === false || $result === null) { 
                // this is a generic error message that should replaced 
                // with more specific ones when possible 
                if ($e) $e->send(E_ERROR, 'AttrValidator: Attribute removed'); 
 
                // remove the attribute 
                unset($attr[$attr_key]); 
            } elseif (is_string($result)) { 
                // generally, if a substitution is happening, there 
                // was some sort of implicit correction going on. We'll 
                // delegate it to the attribute classes to say exactly what. 
 
                // simple substitution 
                $attr[$attr_key] = $result; 
            } else { 
                // nothing happens 
            } 
 
            // we'd also want slightly more complicated substitution 
            // involving an array as the return value, 
            // although we're not sure how colliding attributes would 
            // resolve (certain ones would be completely overriden, 
            // others would prepend themselves). 
        } 
 
        $context->destroy('CurrentAttr'); 
 
        // post transforms 
 
        // global (error reporting untested) 
        foreach ($definition->info_attr_transform_post as $transform) { 
            $attr = $transform->transform($o = $attr, $config, $context); 
            if ($e) { 
                if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); 
            } 
        } 
 
        // local (error reporting untested) 
        foreach ($definition->info[$token->name]->attr_transform_post as $transform) { 
            $attr = $transform->transform($o = $attr, $config, $context); 
            if ($e) { 
                if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); 
            } 
        } 
 
        $token->attr = $attr; 
 
        // destroy CurrentToken if we made it ourselves 
        if (!$current_token) $context->destroy('CurrentToken'); 
 
    } 
 
 
} 
 
// vim: et sw=4 sts=4 
 
 |