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Diffstat (limited to 'program/lib/DB/storage.php')
-rw-r--r-- | program/lib/DB/storage.php | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/program/lib/DB/storage.php b/program/lib/DB/storage.php new file mode 100644 index 000000000..17bffd155 --- /dev/null +++ b/program/lib/DB/storage.php @@ -0,0 +1,504 @@ +<?php + +/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */ + +/** + * Provides an object interface to a table row + * + * PHP versions 4 and 5 + * + * LICENSE: This source file is subject to version 3.0 of the PHP license + * that is available through the world-wide-web at the following URI: + * http://www.php.net/license/3_0.txt. If you did not receive a copy of + * the PHP License and are unable to obtain it through the web, please + * send a note to license@php.net so we can mail you a copy immediately. + * + * @category Database + * @package DB + * @author Stig Bakken <stig@php.net> + * @copyright 1997-2005 The PHP Group + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @version CVS: $Id$ + * @link http://pear.php.net/package/DB + */ + +/** + * Obtain the DB class so it can be extended from + */ +require_once 'DB.php'; + +/** + * Provides an object interface to a table row + * + * It lets you add, delete and change rows using objects rather than SQL + * statements. + * + * @category Database + * @package DB + * @author Stig Bakken <stig@php.net> + * @copyright 1997-2005 The PHP Group + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @version Release: @package_version@ + * @link http://pear.php.net/package/DB + */ +class DB_storage extends PEAR +{ + // {{{ properties + + /** the name of the table (or view, if the backend database supports + updates in views) we hold data from */ + var $_table = null; + + /** which column(s) in the table contains primary keys, can be a + string for single-column primary keys, or an array of strings + for multiple-column primary keys */ + var $_keycolumn = null; + + /** DB connection handle used for all transactions */ + var $_dbh = null; + + /** an assoc with the names of database fields stored as properties + in this object */ + var $_properties = array(); + + /** an assoc with the names of the properties in this object that + have been changed since they were fetched from the database */ + var $_changes = array(); + + /** flag that decides if data in this object can be changed. + objects that don't have their table's key column in their + property lists will be flagged as read-only. */ + var $_readonly = false; + + /** function or method that implements a validator for fields that + are set, this validator function returns true if the field is + valid, false if not */ + var $_validator = null; + + // }}} + // {{{ constructor + + /** + * Constructor + * + * @param $table string the name of the database table + * + * @param $keycolumn mixed string with name of key column, or array of + * strings if the table has a primary key of more than one column + * + * @param $dbh object database connection object + * + * @param $validator mixed function or method used to validate + * each new value, called with three parameters: the name of the + * field/column that is changing, a reference to the new value and + * a reference to this object + * + */ + function DB_storage($table, $keycolumn, &$dbh, $validator = null) + { + $this->PEAR('DB_Error'); + $this->_table = $table; + $this->_keycolumn = $keycolumn; + $this->_dbh = $dbh; + $this->_readonly = false; + $this->_validator = $validator; + } + + // }}} + // {{{ _makeWhere() + + /** + * Utility method to build a "WHERE" clause to locate ourselves in + * the table. + * + * XXX future improvement: use rowids? + * + * @access private + */ + function _makeWhere($keyval = null) + { + if (is_array($this->_keycolumn)) { + if ($keyval === null) { + for ($i = 0; $i < sizeof($this->_keycolumn); $i++) { + $keyval[] = $this->{$this->_keycolumn[$i]}; + } + } + $whereclause = ''; + for ($i = 0; $i < sizeof($this->_keycolumn); $i++) { + if ($i > 0) { + $whereclause .= ' AND '; + } + $whereclause .= $this->_keycolumn[$i]; + if (is_null($keyval[$i])) { + // there's not much point in having a NULL key, + // but we support it anyway + $whereclause .= ' IS NULL'; + } else { + $whereclause .= ' = ' . $this->_dbh->quote($keyval[$i]); + } + } + } else { + if ($keyval === null) { + $keyval = @$this->{$this->_keycolumn}; + } + $whereclause = $this->_keycolumn; + if (is_null($keyval)) { + // there's not much point in having a NULL key, + // but we support it anyway + $whereclause .= ' IS NULL'; + } else { + $whereclause .= ' = ' . $this->_dbh->quote($keyval); + } + } + return $whereclause; + } + + // }}} + // {{{ setup() + + /** + * Method used to initialize a DB_storage object from the + * configured table. + * + * @param $keyval mixed the key[s] of the row to fetch (string or array) + * + * @return int DB_OK on success, a DB error if not + */ + function setup($keyval) + { + $whereclause = $this->_makeWhere($keyval); + $query = 'SELECT * FROM ' . $this->_table . ' WHERE ' . $whereclause; + $sth = $this->_dbh->query($query); + if (DB::isError($sth)) { + return $sth; + } + $row = $sth->fetchRow(DB_FETCHMODE_ASSOC); + if (DB::isError($row)) { + return $row; + } + if (!$row) { + return $this->raiseError(null, DB_ERROR_NOT_FOUND, null, null, + $query, null, true); + } + foreach ($row as $key => $value) { + $this->_properties[$key] = true; + $this->$key = $value; + } + return DB_OK; + } + + // }}} + // {{{ insert() + + /** + * Create a new (empty) row in the configured table for this + * object. + */ + function insert($newpk) + { + if (is_array($this->_keycolumn)) { + $primarykey = $this->_keycolumn; + } else { + $primarykey = array($this->_keycolumn); + } + settype($newpk, "array"); + for ($i = 0; $i < sizeof($primarykey); $i++) { + $pkvals[] = $this->_dbh->quote($newpk[$i]); + } + + $sth = $this->_dbh->query("INSERT INTO $this->_table (" . + implode(",", $primarykey) . ") VALUES(" . + implode(",", $pkvals) . ")"); + if (DB::isError($sth)) { + return $sth; + } + if (sizeof($newpk) == 1) { + $newpk = $newpk[0]; + } + $this->setup($newpk); + } + + // }}} + // {{{ toString() + + /** + * Output a simple description of this DB_storage object. + * @return string object description + */ + function toString() + { + $info = strtolower(get_class($this)); + $info .= " (table="; + $info .= $this->_table; + $info .= ", keycolumn="; + if (is_array($this->_keycolumn)) { + $info .= "(" . implode(",", $this->_keycolumn) . ")"; + } else { + $info .= $this->_keycolumn; + } + $info .= ", dbh="; + if (is_object($this->_dbh)) { + $info .= $this->_dbh->toString(); + } else { + $info .= "null"; + } + $info .= ")"; + if (sizeof($this->_properties)) { + $info .= " [loaded, key="; + $keyname = $this->_keycolumn; + if (is_array($keyname)) { + $info .= "("; + for ($i = 0; $i < sizeof($keyname); $i++) { + if ($i > 0) { + $info .= ","; + } + $info .= $this->$keyname[$i]; + } + $info .= ")"; + } else { + $info .= $this->$keyname; + } + $info .= "]"; + } + if (sizeof($this->_changes)) { + $info .= " [modified]"; + } + return $info; + } + + // }}} + // {{{ dump() + + /** + * Dump the contents of this object to "standard output". + */ + function dump() + { + foreach ($this->_properties as $prop => $foo) { + print "$prop = "; + print htmlentities($this->$prop); + print "<br />\n"; + } + } + + // }}} + // {{{ &create() + + /** + * Static method used to create new DB storage objects. + * @param $data assoc. array where the keys are the names + * of properties/columns + * @return object a new instance of DB_storage or a subclass of it + */ + function &create($table, &$data) + { + $classname = strtolower(get_class($this)); + $obj =& new $classname($table); + foreach ($data as $name => $value) { + $obj->_properties[$name] = true; + $obj->$name = &$value; + } + return $obj; + } + + // }}} + // {{{ loadFromQuery() + + /** + * Loads data into this object from the given query. If this + * object already contains table data, changes will be saved and + * the object re-initialized first. + * + * @param $query SQL query + * + * @param $params parameter list in case you want to use + * prepare/execute mode + * + * @return int DB_OK on success, DB_WARNING_READ_ONLY if the + * returned object is read-only (because the object's specified + * key column was not found among the columns returned by $query), + * or another DB error code in case of errors. + */ +// XXX commented out for now +/* + function loadFromQuery($query, $params = null) + { + if (sizeof($this->_properties)) { + if (sizeof($this->_changes)) { + $this->store(); + $this->_changes = array(); + } + $this->_properties = array(); + } + $rowdata = $this->_dbh->getRow($query, DB_FETCHMODE_ASSOC, $params); + if (DB::isError($rowdata)) { + return $rowdata; + } + reset($rowdata); + $found_keycolumn = false; + while (list($key, $value) = each($rowdata)) { + if ($key == $this->_keycolumn) { + $found_keycolumn = true; + } + $this->_properties[$key] = true; + $this->$key = &$value; + unset($value); // have to unset, or all properties will + // refer to the same value + } + if (!$found_keycolumn) { + $this->_readonly = true; + return DB_WARNING_READ_ONLY; + } + return DB_OK; + } + */ + + // }}} + // {{{ set() + + /** + * Modify an attriute value. + */ + function set($property, $newvalue) + { + // only change if $property is known and object is not + // read-only + if ($this->_readonly) { + return $this->raiseError(null, DB_WARNING_READ_ONLY, null, + null, null, null, true); + } + if (@isset($this->_properties[$property])) { + if (empty($this->_validator)) { + $valid = true; + } else { + $valid = @call_user_func($this->_validator, + $this->_table, + $property, + $newvalue, + $this->$property, + $this); + } + if ($valid) { + $this->$property = $newvalue; + if (empty($this->_changes[$property])) { + $this->_changes[$property] = 0; + } else { + $this->_changes[$property]++; + } + } else { + return $this->raiseError(null, DB_ERROR_INVALID, null, + null, "invalid field: $property", + null, true); + } + return true; + } + return $this->raiseError(null, DB_ERROR_NOSUCHFIELD, null, + null, "unknown field: $property", + null, true); + } + + // }}} + // {{{ &get() + + /** + * Fetch an attribute value. + * + * @param string attribute name + * + * @return attribute contents, or null if the attribute name is + * unknown + */ + function &get($property) + { + // only return if $property is known + if (isset($this->_properties[$property])) { + return $this->$property; + } + $tmp = null; + return $tmp; + } + + // }}} + // {{{ _DB_storage() + + /** + * Destructor, calls DB_storage::store() if there are changes + * that are to be kept. + */ + function _DB_storage() + { + if (sizeof($this->_changes)) { + $this->store(); + } + $this->_properties = array(); + $this->_changes = array(); + $this->_table = null; + } + + // }}} + // {{{ store() + + /** + * Stores changes to this object in the database. + * + * @return DB_OK or a DB error + */ + function store() + { + foreach ($this->_changes as $name => $foo) { + $params[] = &$this->$name; + $vars[] = $name . ' = ?'; + } + if ($vars) { + $query = 'UPDATE ' . $this->_table . ' SET ' . + implode(', ', $vars) . ' WHERE ' . + $this->_makeWhere(); + $stmt = $this->_dbh->prepare($query); + $res = $this->_dbh->execute($stmt, $params); + if (DB::isError($res)) { + return $res; + } + $this->_changes = array(); + } + return DB_OK; + } + + // }}} + // {{{ remove() + + /** + * Remove the row represented by this object from the database. + * + * @return mixed DB_OK or a DB error + */ + function remove() + { + if ($this->_readonly) { + return $this->raiseError(null, DB_WARNING_READ_ONLY, null, + null, null, null, true); + } + $query = 'DELETE FROM ' . $this->_table .' WHERE '. + $this->_makeWhere(); + $res = $this->_dbh->query($query); + if (DB::isError($res)) { + return $res; + } + foreach ($this->_properties as $prop => $foo) { + unset($this->$prop); + } + $this->_properties = array(); + $this->_changes = array(); + return DB_OK; + } + + // }}} +} + +/* + * Local variables: + * tab-width: 4 + * c-basic-offset: 4 + * End: + */ + +?> |