public function validateDefinition(xmldb_table $xmldb_table=null) {
        if (!$xmldb_table) {
            return 'Invalid xmldb_index->validateDefinition() call, $xmldb_table is required.';
        }

        $total = 0;
        foreach ($this->getFields() as $fieldname) {
            if (!$field = $xmldb_table->getField($fieldname)) {
                // argh, we do not have the fields loaded yet, this should not happen during install
                continue;
            }

            switch ($field->getType()) {
                case XMLDB_TYPE_INTEGER:
                    $total += 8; // big int
                    break;

                case XMLDB_TYPE_NUMBER:
                    $total += 12; // this is just a guess
                    break;

                case XMLDB_TYPE_FLOAT:
                    $total += 8; // double precision
                    break;

                case XMLDB_TYPE_CHAR:
                    if ($field->getLength() > self::INDEX_MAX_BYTES / 3) {
                        return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_CHAR field "'.$field->getName().'" can not be indexed because it is too long.'
                                .' Limit is '.(self::INDEX_MAX_BYTES/3).' chars.';
                    }
                    $total += ($field->getLength() * 3); // the most complex utf-8 chars have 3 bytes
                    break;

                case XMLDB_TYPE_TEXT:
                    return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_TEXT field "'.$field->getName().'" can not be indexed';
                    break;

                case XMLDB_TYPE_BINARY:
                    return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_BINARY field "'.$field->getName().'" can not be indexed';
                    break;

                case XMLDB_TYPE_DATETIME:
                    $total += 8; // this is just a guess
                    break;

                case XMLDB_TYPE_TIMESTAMP:
                    $total += 8; // this is just a guess
                    break;
            }
        }

        if ($total > self::INDEX_COMPOSED_MAX_BYTES) {
            return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: the composed index on fields "'.implode(',', $this->getFields()).'" is too long.'
                    .' Limit is '.self::INDEX_COMPOSED_MAX_BYTES.' bytes / '.(self::INDEX_COMPOSED_MAX_BYTES/3).' chars.';
        }

        return null;
    }
public function validateDefinition(xmldb_table $xmldb_table=null) {
        if (!$xmldb_table) {
            return 'Invalid xmldb_index->validateDefinition() call, $xmldb_table is required.';
        }

        $total = 0;
        foreach ($this->getFields() as $fieldname) {
            if (!$field = $xmldb_table->getField($fieldname)) {
                // argh, we do not have the fields loaded yet, this should not happen during install
                continue;
            }

            switch ($field->getType()) {
                case XMLDB_TYPE_INTEGER:
                    $total += 8; // big int
                    break;

                case XMLDB_TYPE_NUMBER:
                    $total += 12; // this is just a guess
                    break;

                case XMLDB_TYPE_FLOAT:
                    $total += 8; // double precision
                    break;

                case XMLDB_TYPE_CHAR:
                    if ($field->getLength() > self::INDEX_MAX_BYTES / 3) {
                        return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_CHAR field "'.$field->getName().'" can not be indexed because it is too long.'
                                .' Limit is '.(self::INDEX_MAX_BYTES/3).' chars.';
                    }
                    $total += ($field->getLength() * 3); // the most complex utf-8 chars have 3 bytes
                    break;

                case XMLDB_TYPE_TEXT:
                    return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_TEXT field "'.$field->getName().'" can not be indexed';
                    break;

                case XMLDB_TYPE_BINARY:
                    return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_BINARY field "'.$field->getName().'" can not be indexed';
                    break;

                case XMLDB_TYPE_DATETIME:
                    $total += 8; // this is just a guess
                    break;

                case XMLDB_TYPE_TIMESTAMP:
                    $total += 8; // this is just a guess
                    break;
            }
        }

        if ($total > self::INDEX_COMPOSED_MAX_BYTES) {
            return 'Invalid index definition in table {'.$xmldb_table->getName(). '}: the composed index on fields "'.implode(',', $this->getFields()).'" is too long.'
                    .' Limit is '.self::INDEX_COMPOSED_MAX_BYTES.' bytes / '.(self::INDEX_COMPOSED_MAX_BYTES/3).' chars.';
        }

        return null;
    }
public function validateDefinition ( xmldb_table $ xmldb_table = null ) { if ( ! $ xmldb_table ) { return 'Invalid xmldb_index->validateDefinition() call, $xmldb_table is required.' ; } $ total = 0 ; foreach ( $ this -> getFields ( ) as $ fieldname ) { if ( ! $ field = $ xmldb_table -> getField ( $ fieldname ) ) { // argh, we do not have the fields loaded yet, this should not happen during install continue ; } switch ( $ field -> getType ( ) ) { case XMLDB_TYPE_INTEGER : $ total += 8 ; // big int break ; case XMLDB_TYPE_NUMBER : $ total += 12 ; // this is just a guess break ; case XMLDB_TYPE_FLOAT : $ total += 8 ; // double precision break ; case XMLDB_TYPE_CHAR : if ( $ field -> getLength ( ) > self :: INDEX_MAX_BYTES / 3 ) { return 'Invalid index definition in table {' . $ xmldb_table -> getName ( ) . '}: XMLDB_TYPE_CHAR field "' . $ field -> getName ( ) . '" can not be indexed because it is too long.' . ' Limit is ' . ( self :: INDEX_MAX_BYTES / 3 ) . ' chars.' ; } $ total += ( $ field -> getLength ( ) * 3 ) ; // the most complex utf-8 chars have 3 bytes break ; case XMLDB_TYPE_TEXT : return 'Invalid index definition in table {' . $ xmldb_table -> getName ( ) . '}: XMLDB_TYPE_TEXT field "' . $ field -> getName ( ) . '" can not be indexed' ; break ; case XMLDB_TYPE_BINARY : return 'Invalid index definition in table {' . $ xmldb_table -> getName ( ) . '}: XMLDB_TYPE_BINARY field "' . $ field -> getName ( ) . '" can not be indexed' ; break ; case XMLDB_TYPE_DATETIME : $ total += 8 ; // this is just a guess break ; case XMLDB_TYPE_TIMESTAMP : $ total += 8 ; // this is just a guess break ; } } if ( $ total > self :: INDEX_COMPOSED_MAX_BYTES ) { return 'Invalid index definition in table {' . $ xmldb_table -> getName ( ) . '}: the composed index on fields "' . implode ( ',' , $ this -> getFields ( ) ) . '" is too long.' . ' Limit is ' . self :: INDEX_COMPOSED_MAX_BYTES . ' bytes / ' . ( self :: INDEX_COMPOSED_MAX_BYTES / 3 ) . ' chars.' ; } return null ; }
Validates the index restrictions.

The error message should not be localised because it is intended for developers,
end users and admins should never see these problems!

@param xmldb_table $xmldb_table optional when object is table
@return string null if ok, error message if problem found
Validates the index restrictions .