<?php // $Id: XMLDBField.class.php,v 1.12.2.2 2008/01/02 16:47:34 stronk7 Exp $

///////////////////////////////////////////////////////////////////////////
//                                                                       //
// NOTICE OF COPYRIGHT                                                   //
//                                                                       //
// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
//          http://moodle.com                                            //
//                                                                       //
// Copyright (C) 1999 onwards Martin Dougiamas        http://dougiamas.com  //
//           (C) 2001-3001 Eloy Lafuente (stronk7) http://contiento.com  //
//                                                                       //
// This program is free software; you can redistribute it and/or modify  //
// it under the terms of the GNU General Public License as published by  //
// the Free Software Foundation; either version 2 of the License, or     //
// (at your option) any later version.                                   //
//                                                                       //
// This program is distributed in the hope that it will be useful,       //
// but WITHOUT ANY WARRANTY; without even the implied warranty of        //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         //
// GNU General Public License for more details:                          //
//                                                                       //
//          http://www.gnu.org/copyleft/gpl.html                         //
//                                                                       //
///////////////////////////////////////////////////////////////////////////

/// This class represent one XMLDB Field

class XMLDBField extends XMLDBObject {

    var $type;
    var $length;
    var $unsigned;
    var $notnull;
    var $default;
    var $sequence;
    var $enum;
    var $enumvalues;
    var $decimals;

    /**
     * Creates one new XMLDBField
     */
    function XMLDBField($name) {
        parent::XMLDBObject($name);
        $this->type = NULL;
        $this->length = NULL;
        $this->unsigned = true;
        $this->notnull = false;
        $this->default = NULL;
        $this->sequence = false;
        $this->enum = false;
        $this->enumvalues = NULL;
        $this->decimals = NULL;
    }

    /**
     * Set all the attributes of one XMLDBField
     *
     * @param string type XMLDB_TYPE_INTEGER, XMLDB_TYPE_NUMBER, XMLDB_TYPE_CHAR, XMLDB_TYPE_TEXT, XMLDB_TYPE_BINARY
     * @param string precision length for integers and chars, two-comma separated numbers for numbers and 'small', 'medium', 'big' for texts and binaries
     * @param string unsigned XMLDB_UNSIGNED or null (or false)
     * @param string notnull XMLDB_NOTNULL or null (or false)
     * @param string sequence XMLDB_SEQUENCE or null (or false)
     * @param string enum XMLDB_ENUM or null (or false)
     * @param array enumvalues an array of possible values if XMLDB_ENUM is set
     * @param string default meaningful default o null (or false)
     */
    function setAttributes($type, $precision=null, $unsigned=null, $notnull=null, $sequence=null, $enum=null, $enumvalues=null, $default=null, $previous=null) {
        $this->type = $type;
    /// Try to split the precision into length and decimals and apply
    /// each one as needed
        $precisionarr = explode(',', $precision);
        if (isset($precisionarr[0])) {
            $this->length = trim($precisionarr[0]);
        }
        if (isset($precisionarr[1])) {
            $this->decimals = trim($precisionarr[1]);
        }
        $this->precision = $type;
        $this->unsigned = !empty($unsigned) ? true : false;
        $this->notnull = !empty($notnull) ? true : false;
        $this->sequence = !empty($sequence) ? true : false;
        $this->enum = !empty($enum) ? true : false;
    /// Accept both quoted and non-quoted vales (quoting them)a
        if (is_array($enumvalues)) {
            $this->enumvalues = array();
            foreach ($enumvalues as $value) {
            /// trim each value quotes
                $value = trim($value, "'");
            /// add them back
                $value = "'" . $value . "'";
                $this->enumvalues[] = $value;
            }
        }
        $this->setDefault($default);

        $this->previous = $previous;
    }

    /**
     * Get the type
     */
    function getType() {
        return $this->type;
    }

    /**
     * Get the length
     */
    function getLength() {
        return $this->length;
    }

    /**
     * Get the decimals
     */
    function getDecimals() {
        return $this->decimals;
    }

    /**
     * Get the notnull
     */
    function getNotNull() {
        return $this->notnull;
    }

    /**
     * Get the unsigned
     */
    function getUnsigned() {
        return $this->unsigned;
    }

    /**
     * Get the sequence
     */
    function getSequence() {
        return $this->sequence;
    }

    /**
     * Get the enum
     */
    function getEnum() {
        return $this->enum;
    }

    /**
     * Get the enumvalues
     */
    function getEnumValues() {
        return $this->enumvalues;
    }

    /**
     * Get the default
     */
    function getDefault() {
        return $this->default;
    }

    /**
     * Set the field type
     */
    function setType($type) {
        $this->type = $type;
    }

    /**
     * Set the field length
     */
    function setLength($length) {
        $this->length = $length;
    }

    /**
     * Set the field decimals
     */
    function setDecimals($decimals) {
        $this->decimals = $decimals;
    }

    /**
     * Set the field unsigned
     */
    function setUnsigned($unsigned=true) {
        $this->unsigned = $unsigned;
    }

    /**
     * Set the field notnull
     */
    function setNotNull($notnull=true) {
        $this->notnull = $notnull;
    }

    /**
     * Set the field sequence
     */
    function setSequence($sequence=true) {
        $this->sequence = $sequence;
    }

    /**
     * Set the field enum
     */
    function setEnum($enum=true) {
        $this->enum = $enum;
    }

    /**
     * Set the field enumvalues, quoting unquoted values
     */
    function setEnumValues($enumvalues) {
        if (is_array($enumvalues)) {
            $this->enumvalues = array();
            foreach ($enumvalues as $value) {
            /// trim each value quotes
                $value = trim($value, "'");
            /// add them back
                $value = "'" . $value . "'";
                $this->enumvalues[] = $value;
            }
        }
    }

    /**
     * Set the field default
     */
    function setDefault($default) {
    /// Check, warn and auto-fix '' (empty) defaults for CHAR NOT NULL columns, changing them
    /// to NULL so XMLDB will apply the proper default
        if ($this->type == XMLDB_TYPE_CHAR && $this->notnull && $default === '') {
            $this->errormsg = 'XMLDB has detected one CHAR NOT NULL column (' . $this->name . ") with '' (empty string) as DEFAULT value. This type of columns must have one meaningful DEFAULT declared or none (NULL). XMLDB have fixed it automatically changing it to none (NULL). The process will continue ok and proper defaults will be created accordingly with each DB requirements. Please fix it in source (XML and/or upgrade script) to avoid this message to be displayed.";
            $this->debug($this->errormsg);
            $default = NULL;
        }
        $this->default = $default;
    }

    /**
     * Load data from XML to the table
     */
    function arr2XMLDBField($xmlarr) {

        $result = true;

    /// Debug the table
    /// traverse_xmlize($xmlarr);                   //Debug
    /// print_object ($GLOBALS['traverse_array']);  //Debug
    /// $GLOBALS['traverse_array']="";              //Debug

    /// Process table attributes (name, type, length, unsigned,
    /// notnull, sequence, enum, enumvalues, decimals, comment,
    /// previous, next)
        if (isset($xmlarr['@']['NAME'])) {
            $this->name = trim($xmlarr['@']['NAME']);
        } else {
            $this->errormsg = 'Missing NAME attribute';
            $this->debug($this->errormsg);
            $result = false;
        }

        if (isset($xmlarr['@']['TYPE'])) {
        /// Check for valid type
            $type = $this->getXMLDBFieldType(trim($xmlarr['@']['TYPE']));
            if ($type) {
                $this->type = $type;
            } else {
                $this->errormsg = 'Invalid TYPE attribute';
                $this->debug($this->errormsg);
                $result = false;
            }
        } else {
            $this->errormsg = 'Missing TYPE attribute';
            $this->debug($this->errormsg);
            $result = false;
        }

        if (isset($xmlarr['@']['LENGTH'])) {
            $length = trim($xmlarr['@']['LENGTH']);
        /// Check for integer values
            if ($this->type == XMLDB_TYPE_INTEGER ||
                $this->type == XMLDB_TYPE_NUMBER ||
                $this->type == XMLDB_TYPE_CHAR) {
                if (!(is_numeric($length)&&(intval($length)==floatval($length)))) {
                    $this->errormsg = 'Incorrect LENGTH attribute for int, number or char fields';
                    $this->debug($this->errormsg);
                    $result = false;
                } else if (!$length) {
                    $this->errormsg = 'Zero LENGTH attribute';
                    $this->debug($this->errormsg);
                    $result = false;
                }
            }
        /// Check for big, medium, small to be applied to text and binary
            if ($this->type == XMLDB_TYPE_TEXT ||
                $this->type == XMLDB_TYPE_BINARY) {
                if (!$length) {
                    $length == 'big';
                }
                if ($length != 'big' &&
                    $length != 'medium' &&
                    $length != 'small') {
                    $this->errormsg = 'Incorrect LENGTH attribute for text and binary fields (only big, medium and small allowed)';
                    $this->debug($this->errormsg);
                    $result = false;
                }
            }
        /// Finally, set the length
            $this->length = $length;
        }

        if (isset($xmlarr['@']['UNSIGNED'])) {
            $unsigned = strtolower(trim($xmlarr['@']['UNSIGNED']));
            if ($unsigned == 'true') {
                $this->unsigned = true;
            } else if ($unsigned == 'false') {
                $this->unsigned = false;
            } else {
                $this->errormsg = 'Incorrect UNSIGNED attribute (true/false allowed)';
                $this->debug($this->errormsg);
                $result = false;
            }
        }

        if (isset($xmlarr['@']['NOTNULL'])) {
            $notnull = strtolower(trim($xmlarr['@']['NOTNULL']));
            if ($notnull == 'true') {
                $this->notnull = true;
            } else if ($notnull == 'false') {
                $this->notnull = false;
            } else {
                $this->errormsg = 'Incorrect NOTNULL attribute (true/false allowed)';
                $this->debug($this->errormsg);
                $result = false;
            }
        }

        if (isset($xmlarr['@']['SEQUENCE'])) {
            $sequence = strtolower(trim($xmlarr['@']['SEQUENCE']));
            if ($sequence == 'true') {
                $this->sequence = true;
            } else if ($sequence == 'false') {
                $this->sequence = false;
            } else {
                $this->errormsg = 'Incorrect SEQUENCE attribute (true/false allowed)';
                $this->debug($this->errormsg);
                $result = false;
            }
        }

        if (isset($xmlarr['@']['DEFAULT'])) {
            $this->setDefault(trim($xmlarr['@']['DEFAULT']));
        }

        if (isset($xmlarr['@']['ENUM'])) {
            $enum = strtolower(trim($xmlarr['@']['ENUM']));
            if ($enum == 'true') {
                $this->enum = true;
            } else if ($enum == 'false') {
                $this->enum = false;
            } else {
                $this->errormsg = 'Incorrect ENUM attribute (true/false allowed)';
                $this->debug($this->errormsg);
                $result = false;
            }
        }

        if (isset($xmlarr['@']['ENUMVALUES'])) {
            $enumvalues = trim($xmlarr['@']['ENUMVALUES']);
            if (!$this->enum) {
                $this->errormsg = 'Wrong ENUMVALUES attribute (not ENUM)';
                $this->debug($this->errormsg);
                $result = false;
                $this->enumvalues = $enumvalues;
            } else {
            /// Check we have a valid list (comma separated of quoted values)
                $enumarr = explode(',',$enumvalues);
                if ($enumarr) {
                    foreach ($enumarr as $key => $enumelement) {
                    /// Clear some spaces
                        $enumarr[$key] = trim($enumelement);
                        $enumelement = trim($enumelement);
                    /// Skip if under error
                        if (!$result) {
                            continue;
                        }
                    /// Look for quoted strings
                        if (substr($enumelement, 0, 1) != "'" ||
                            substr($enumelement, -1, 1) != "'") {
                            $this->errormsg = 'Incorrect ENUMVALUES attribute (some value is not properly quoted)';
                            $this->debug($this->errormsg);
                            $result = false;
                        }
                    }
                } else {
                    $this->errormsg = 'Incorrect ENUMVALUES attribute (comma separated of quoted values)';
                    $this->debug($this->errormsg);
                    $result = false;
                }
            }
        } else if ($this->enum) {
            $this->errormsg = 'Incorrect ENUMVALUES attribute (field is not declared as ENUM)';
            $this->debug($this->errormsg);
            $result = false;
        }
    /// Finally, set the value
        if ($this->enum) {
            $this->enumvalues = $enumarr;
        }

        $decimals = NULL;
        if (isset($xmlarr['@']['DECIMALS'])) {
            $decimals = trim($xmlarr['@']['DECIMALS']);
        /// Check for integer values
            if ($this->type == XMLDB_TYPE_NUMBER ||
                $this->type == XMLDB_TYPE_FLOAT) {
                if (!(is_numeric($decimals)&&(intval($decimals)==floatval($decimals)))) {
                    $this->errormsg = 'Incorrect DECIMALS attribute for number field';
                    $this->debug($this->errormsg);
                    $result = false;
                } else if ($this->length <= $decimals){
                    $this->errormsg = 'Incorrect DECIMALS attribute (bigget than length)';
                    $this->debug($this->errormsg);
                    $result = false;
                }
            } else {
                $this->errormsg = 'Incorrect DECIMALS attribute for non-number field';
                $this->debug($this->errormsg);
                $result = false;
            }
        } else {
            if ($this->type == XMLDB_TYPE_NUMBER) {
                $decimals = 0;
            }
        }
     // Finally, set the decimals
        if ($this->type == XMLDB_TYPE_NUMBER ||
            $this->type == XMLDB_TYPE_FLOAT) {
            $this->decimals = $decimals;
        }

        if (isset($xmlarr['@']['COMMENT'])) {
            $this->comment = trim($xmlarr['@']['COMMENT']);
        }

        if (isset($xmlarr['@']['PREVIOUS'])) {
            $this->previous = trim($xmlarr['@']['PREVIOUS']);
        }

        if (isset($xmlarr['@']['NEXT'])) {
            $this->next = trim($xmlarr['@']['NEXT']);
        }

    /// Set some attributes
        if ($result) {
            $this->loaded = true;
        }
        $this->calculateHash();
        return $result;
    }

    /**
     * This function returns the correct XMLDB_TYPE_XXX value for the
     * string passed as argument
     */
    function getXMLDBFieldType($type) {

        $result = XMLDB_TYPE_INCORRECT;

        switch (strtolower($type)) {
            case 'int':
                $result = XMLDB_TYPE_INTEGER;
                break;
            case 'number':
                $result = XMLDB_TYPE_NUMBER;
                break;
            case 'float':
                $result = XMLDB_TYPE_FLOAT;
                break;
            case 'char':
                $result = XMLDB_TYPE_CHAR;
                break;
            case 'text':
                $result = XMLDB_TYPE_TEXT;
                break;
            case 'binary':
                $result = XMLDB_TYPE_BINARY;
                break;
            case 'datetime':
                $result = XMLDB_TYPE_DATETIME;
                break;
        }
    /// Return the normalized XMLDB_TYPE
        return $result;
    }

    /**
     * This function returns the correct name value for the
     * XMLDB_TYPE_XXX passed as argument
     */
    function getXMLDBTypeName($type) {

        $result = "";

        switch (strtolower($type)) {
            case XMLDB_TYPE_INTEGER:
                $result = 'int';
                break;
            case XMLDB_TYPE_NUMBER:
                $result = 'number';
                break;
            case XMLDB_TYPE_FLOAT:
                $result = 'float';
                break;
            case XMLDB_TYPE_CHAR:
                $result = 'char';
                break;
            case XMLDB_TYPE_TEXT:
                $result = 'text';
                break;
            case XMLDB_TYPE_BINARY:
                $result = 'binary';
                break;
            case XMLDB_TYPE_DATETIME:
                $result = 'datetime';
                break;
        }
    /// Return the normalized name
        return $result;
    }

    /**
     * This function calculate and set the hash of one XMLDBField
     */
     function calculateHash($recursive = false) {
        if (!$this->loaded) {
            $this->hash = NULL;
        } else {
            $key = $this->name . $this->type . $this->length .
                   $this->unsigned . $this->notnull . $this->sequence .
                   $this->decimals . $this->comment;
            if ($this->enum) {
                $key .= implode(', ',$this->enumvalues);
            }
            $this->hash = md5($key);
        }
    }

    /**
     *This function will output the XML text for one field
     */
    function xmlOutput() {
        $o = '';
        $o.= '        <FIELD NAME="' . $this->name . '"';
        $o.= ' TYPE="' . $this->getXMLDBTypeName($this->type) . '"';
        if ($this->length) {
            $o.= ' LENGTH="' . $this->length . '"';
        }
        if ($this->notnull) {
            $notnull = 'true';
        } else {
            $notnull = 'false';
        }
        $o.= ' NOTNULL="' . $notnull . '"';
        if ($this->unsigned) {
            $unsigned = 'true';
        } else {
            $unsigned = 'false';
        }
        if ($this->type == XMLDB_TYPE_INTEGER ||
            $this->type == XMLDB_TYPE_NUMBER ||
            $this->type == XMLDB_TYPE_FLOAT) {
            if ($this->unsigned) {
                $unsigned = 'true';
            } else {
                $unsigned = 'false';
            }
            $o.= ' UNSIGNED="' . $unsigned . '"';
        }
        if (!$this->sequence && $this->default !== NULL) {
            $o.= ' DEFAULT="' . $this->default . '"';
        }
        if ($this->sequence) {
            $sequence = 'true';
        } else {
            $sequence = 'false';
        }
        $o.= ' SEQUENCE="' . $sequence . '"';
        if ($this->enum) {
            $enum = 'true';
        } else {
            $enum = 'false';
        }
        $o.= ' ENUM="' . $enum . '"';
        if ($this->enum) {
            $o.= ' ENUMVALUES="' . implode(', ', $this->enumvalues) . '"';
        }
        if ($this->decimals !== NULL) {
            $o.= ' DECIMALS="' . $this->decimals . '"';
        }
        if ($this->comment) {
            $o.= ' COMMENT="' . htmlspecialchars($this->comment) . '"';
        }
        if ($this->previous) {
            $o.= ' PREVIOUS="' . $this->previous . '"';
        }
        if ($this->next) {
            $o.= ' NEXT="' . $this->next . '"';
        }
        $o.= '/>' . "\n";

        return $o;
    }

    /**
     * This function will set all the attributes of the XMLDBField object
     * based on information passed in one ADOField
     */
    function setFromADOField($adofield) {

    /// Calculate the XMLDB_TYPE
        switch (strtolower($adofield->type)) {
            case 'int':
            case 'tinyint':
            case 'smallint':
            case 'bigint':
            case 'integer':
                $this->type = XMLDB_TYPE_INTEGER;
                break;
            case 'number':
            case 'decimal':
            case 'dec':
            case 'numeric':
                $this->type = XMLDB_TYPE_NUMBER;
                break;
            case 'float':
            case 'double':
                $this->type = XMLDB_TYPE_FLOAT;
                break;
            case 'char':
            case 'varchar':
            case 'enum':
                $this->type = XMLDB_TYPE_CHAR;
                break;
            case 'text':
            case 'tinytext':
            case 'mediumtext':
            case 'longtext':
                $this->type = XMLDB_TYPE_TEXT;
                break;
            case 'blob':
            case 'tinyblob':
            case 'mediumblob':
            case 'longblob':
                $this->type = XMLDB_TYPE_BINARY;
                break;
            case 'datetime':
            case 'timestamp':
                $this->type = XMLDB_TYPE_DATETIME;
                break;
            default:
                $this->type = XMLDB_TYPE_TEXT;
        }
    /// Calculate the length of the field
        if ($adofield->max_length > 0 &&
               ($this->type == XMLDB_TYPE_INTEGER ||
                $this->type == XMLDB_TYPE_NUMBER  ||
                $this->type == XMLDB_TYPE_FLOAT   ||
                $this->type == XMLDB_TYPE_CHAR)) {
            $this->length = $adofield->max_length;
        }
        if ($this->type == XMLDB_TYPE_TEXT) {
            switch (strtolower($adofield->type)) {
                case 'tinytext':
                case 'text':
                    $this->length = 'small';
                    break;
                case 'mediumtext':
                    $this->length = 'medium';
                    break;
                case 'longtext':
                    $this->length = 'big';
                    break;
                default:
                    $this->length = 'small';
            }
        }
        if ($this->type == XMLDB_TYPE_BINARY) {
            switch (strtolower($adofield->type)) {
                case 'tinyblob':
                case 'blob':
                    $this->length = 'small';
                    break;
                case 'mediumblob':
                    $this->length = 'medium';
                    break;
                case 'longblob':
                    $this->length = 'big';
                    break;
                default:
                    $this->length = 'small';
            }
        }
    /// Calculate the decimals of the field
        if ($adofield->max_length > 0 &&
            $adofield->scale &&
               ($this->type == XMLDB_TYPE_NUMBER ||
                $this->type == XMLDB_TYPE_FLOAT)) {
            $this->decimals = $adofield->scale;
        }
    /// Calculate the unsigned field
        if ($adofield->unsigned &&
               ($this->type == XMLDB_TYPE_INTEGER ||
                $this->type == XMLDB_TYPE_NUMBER  ||
                $this->type == XMLDB_TYPE_FLOAT)) {
            $this->unsigned = true;
        }
    /// Calculate the notnull field
        if ($adofield->not_null) {
            $this->notnull = true;
        }
    /// Calculate the default field
        if ($adofield->has_default) {
            $this->default = $adofield->default_value;
        }
    /// Calculate the sequence field
        if ($adofield->auto_increment) {
            $this->sequence = true;
        /// Sequence fields are always unsigned
            $this->unsigned = true;
        }
    /// Calculate the enum and enumvalues field
        if ($adofield->type == 'enum') {
            $this->enum = true;
            $this->enumvalues = $adofield->enums;
        }
    /// Some more fields
        $this->loaded = true;
        $this->changed = true;
    }

    /**
     * Returns the PHP code needed to define one XMLDBField
     */
    function getPHP($includeprevious=true) {

        $result = '';

    /// The XMLDBTYPE
        switch ($this->getType()) {
            case XMLDB_TYPE_INTEGER:
                $result .= 'XMLDB_TYPE_INTEGER' . ', ';
                break;
            case XMLDB_TYPE_NUMBER:
                $result .= 'XMLDB_TYPE_NUMBER' . ', ';
                break;
            case XMLDB_TYPE_FLOAT:
                $result .= 'XMLDB_TYPE_FLOAT' . ', ';
                break;
            case XMLDB_TYPE_CHAR:
                $result .= 'XMLDB_TYPE_CHAR' . ', ';
                break;
            case XMLDB_TYPE_TEXT:
                $result .= 'XMLDB_TYPE_TEXT' . ', ';
                break;
            case XMLDB_TYPE_BINARY:
                $result .= 'XMLDB_TYPE_BINARY' . ', ';
                break;
            case XMLDB_TYPE_DATETIME:
                $result .= 'XMLDB_TYPE_DATETIME' . ', ';
                break;
            case XMLDB_TYPE_TIMESTAMP:
                $result .= 'XMLDB_TYPE_TIMESTAMP' . ', ';
                break;
        }
    /// The length
        $length = $this->getLength();
        $decimals = $this->getDecimals();
        if (!empty($length)) {
            $result .= "'" . $length;
            if (!empty($decimals)) {
                $result .= ', ' . $decimals;
            }
            $result .= "', ";
        } else {
            $result .= 'null, ';
        }
    /// Unsigned (only applicable to numbers)
        $unsigned = $this->getUnsigned();
        if (!empty($unsigned) &&
           ($this->getType() == XMLDB_TYPE_INTEGER || $this->getType() == XMLDB_TYPE_NUMBER || $this->getType() == XMLDB_TYPE_FLOAT)) {
            $result .= 'XMLDB_UNSIGNED' . ', ';
        } else {
            $result .= 'null, ';
        }
    /// Not Null
        $notnull = $this->getNotnull();
        if (!empty($notnull)) {
            $result .= 'XMLDB_NOTNULL' . ', ';
        } else {
            $result .= 'null, ';
        }
    /// Sequence
        $sequence = $this->getSequence();
        if (!empty($sequence)) {
            $result .= 'XMLDB_SEQUENCE' . ', ';
        } else {
            $result .= 'null, ';
        }
    /// Enum
        $enum = $this->getEnum();
        if (!empty($enum)) {
            $result .= 'XMLDB_ENUM' . ', ';
        } else {
            $result .= 'null, ';
        }
    /// Enumvalues
        $enumvalues = $this->getEnumValues();
        if (!empty($enumvalues)) {
            $result .= 'array(' . implode(', ', $enumvalues) . '), ';
        } else {
            $result .= 'null, ';
        }
    /// Default
        $default =  $this->getDefault();
        if ($default !== null && !$this->getSequence()) {
            $result .= "'" . $default . "'";
        } else {
            $result .= 'null';
        }
    /// Previous (decided by parameter)
        if ($includeprevious) {
            $previous = $this->getPrevious();
            if (!empty($previous)) {
                $result .= ", '" . $previous . "'";
            } else {
                $result .= ', null';
            }
        }
    /// Return result
        return $result;
    }

    /**
     * Shows info in a readable format
     */
    function readableInfo() {
        $o = '';
    /// type
        $o .= $this->getXMLDBTypeName($this->type);
    /// length
        if ($this->type == XMLDB_TYPE_INTEGER ||
            $this->type == XMLDB_TYPE_NUMBER  ||
            $this->type == XMLDB_TYPE_FLOAT   ||
            $this->type == XMLDB_TYPE_CHAR) {
            if ($this->length) {
                $o .= ' (' . $this->length;
                if ($this->type == XMLDB_TYPE_NUMBER  ||
                    $this->type == XMLDB_TYPE_FLOAT) {
                    if ($this->decimals !== NULL) {
                        $o .= ', ' . $this->decimals;
                    }
                }
                $o .= ')';
            }
        }
        if ($this->type == XMLDB_TYPE_TEXT ||
            $this->type == XMLDB_TYPE_BINARY) {
                $o .= ' (' . $this->length . ')';
        }
    /// enum
        if ($this->enum) {
            $o .= ' enum(' . implode(', ', $this->enumvalues) . ')';
        }
    /// unsigned
        if ($this->type == XMLDB_TYPE_INTEGER ||
            $this->type == XMLDB_TYPE_NUMBER ||
            $this->type == XMLDB_TYPE_FLOAT) {
            if ($this->unsigned) {
                $o .= ' unsigned';
            } else {
                $o .= ' signed';
            }
        }
    /// not null
        if ($this->notnull) {
            $o .= ' not null';
        }
    /// default
        if ($this->default !== NULL) {
            $o .= ' default ';
            if ($this->type == XMLDB_TYPE_CHAR ||
                $this->type == XMLDB_TYPE_TEXT) {
                    $o .= "'" . $this->default . "'";
            } else {
                $o .= $this->default;
            }
        }
    /// sequence
        if ($this->sequence) {
            $o .= ' auto-numbered';
        }

        return $o;
    }
}

?>