<?php
/**
* This file contains the DBColumn class.
*
* @author Gonzalo Chumillas <gonzalo@soloproyectos.com>
* @package database
*/
require_once dirname(__DIR__) . "/database/exceptions/column-not-editable-db-exception.php";
require_once dirname(__DIR__) . "/database/db-query.php";
require_once dirname(__DIR__) . "/database/db-table.php";
/**
* class DBColumn
* @package database
*/
class DBColumn {
/**
* Query object.
* @var DBColumn
*/
private $query;
/**
* Column table.
* @var DBTable
*/
private $table = NULL;
/**
* Column name.
* @var string
*/
private $name = "";
/**
* Column aliases.
* @var array[string]
*/
private $aliases = array();
/**
* Column value.
* @var string
*/
private $value = "";
/**
* Column default value.
* @var string
*/
private $default_value = "";
/**
* Column links.
* @var array[DBColumn]
*/
private $links = array();
/**
* Has value changed?
* @var boolean
*/
private $has_changed = FALSE;
/**
* Has a default value?
* @var boolean
*/
private $has_default_value = FALSE;
/**
* Is accessible?
* @var boolean
*/
private $accessible = FALSE;
/**
* @param DBQuery $query
* @param String $table Table alias.
* @param String $name Column name.
*/
public function __construct($query, $table, $name) {
$this->query = $query;
$this->name = $name;
if (!util::isEmpty($table)) {
$this->table = $this->query->registerTable($table);
$this->table->registerColumn($this);
}
}
public function reset() {
$this->value = "";
$this->has_changed = FALSE;
}
/**
* Gets the column table.
* @return DBTable
*/
public function getTable() {
return $this->table;
}
/**
* Gets column name.
* @return string
*/
public function getName() {
return $this->name;
}
/**
* Gets full name of the column.
* The full name is composed by the 'table alias' and the 'column name' separated by a dot.
* For example: table.field It identifies the column in the query in a unique way.
* @return string
*/
public function getFullName() {
$ret = "";
if ($this->isComputed()) {
if (count($this->aliases) > 0) {
// first alias
$ret = $this->aliases[0];
} else {
// column position
$columns = $this->query->getColumns();
$ret = "" . array_search($this, $columns, TRUE);
}
} else {
// table alias
$table_alias = $this->table->getAlias();
if (preg_match("/\W+/", $table_alias)) {
$table_alias = "`$table_alias`";
}
// column name
$column_name = $this->name;
if (preg_match("/\W+/", $column_name)) {
$column_name = "`$column_name`";
}
$ret = "$table_alias.$column_name";
}
return $ret;
}
/**
* Gets value.
* @return string
*/
public function getValue() {
$ret = "";
if ($this->hasValue()) {
$ret = $this->value;
} else
if ($this->hasOriginalValue()) {
$ret = $this->getOriginalValue();
}
return $ret;
}
/**
* Sets column value.
* @param string $value
* @throws ColumnNotEditableDBException if the column is not editable.
*/
public function setValue($value, &$stack = array()) {
if ($this->isComputed()) {
throw new ColumnNotEditableDBException($this, ColumnNotEditableDBException::COMPUTED);
}
$table = $this->table;
$pk = $table->getPrimaryKey();
$this->value = $value;
$this->has_changed = TRUE;
array_push($stack, $this);
if ($pk == NULL) {
$column = $this->getFullName();
$table = $this->table->getAlias();
throw new ColumnNotEditableDBException($this, ColumnNotEditableDBException::PK_MISSING);
} else {
$pk_value = $pk->getOriginalValue();
if (util::isEmpty($pk_value) && !$pk->isEditable()) {
throw new ColumnNotEditableDBException($this, ColumnNotEditableDBException::PK_NOT_EDITABLE);
}
}
foreach ($this->links as $link) {
if (array_search($link, $stack, TRUE) === FALSE) {
if (!$link->isEditable()) {
throw new ColumnNotEditableDBException($this, ColumnNotEditableDBException::LINK_NOT_EDITABLE);
}
$link->setValue($value, $stack);
}
}
}
/**
* Deletes column value.
*/
public function delValue() {
$this->value = "";
$this->has_changed = FALSE;
}
/**
* Gets default value.
* @return string
*/
public function getDefaultValue() {
return $this->default_value;
}
/**
* Sets default value.
* @param string $value
*/
public function setDefaultValue($value) {
$this->default_value = $value;
$this->has_default_value = TRUE;
}
/**
* Gets original value.
* @return string
*/
public function getOriginalValue() {
return $this->query->getOriginalValue($this);
}
/**
* Sets original column value.
* @param string $value
*/
public function setOriginalValue($value) {
$this->query->setOriginalValue($this, $value);
}
/**
* Adds a column link.
* @param DBColumn $column
*/
public function registerLink($column) {
if (array_search($column, $this->links, TRUE) === FALSE) {
array_push($this->links, $column);
}
}
/**
* Is column accessible?
* @return boolean
*/
public function isAccessible() {
return $this->accessible;
}
/**
* Sets column accessibility.
* @param boolean $accessible
*/
public function setAccessible($accessible) {
$this->accessible = $accessible;
}
/**
* Is the column editable?
* A column is editable when:
* 2. it is not a constant (it hasn't a default value)
* 3. its parent table has primary key
* 4. all its linked columns are editable
* @param object $column
* @return boolean
*/
public function isEditable(&$stack = array()) {
$ret = !$this->isComputed() && $this->table->getPrimaryKey() != NULL;
if ($ret) {
array_push($stack, $this);
foreach ($this->links as $link) {
if (array_search($link, $stack, TRUE) === FALSE) {
if (!$link->isEditable($stack)) {
$ret = FALSE;
break;
}
}
}
}
return $ret;
}
/**
* Is primary key?
* @param boolean
*/
public function isPrimaryKey() {
return $this->is_primary_key;
}
/**
* Is a computed column?
*/
public function isComputed() {
return $this->table == NULL;
}
/**
* Marks as primary key.
* @param boolean $value
*/
public function setPrimaryKey($value) {
$this->is_primary_key = $value;
if (!$this->isComputed() && $this->is_primary_key) {
$this->table->setPrimaryKey($this);
}
}
/**
* Has changed the value?
* @return boolean
*/
public function hasChanged() {
return $this->has_changed;
}
/**
* Has a value?
* @return boolean
*/
public function hasValue() {
return $this->hasChanged();
}
/**
* Has a default value?
* @return boolean
*/
public function hasDefaultValue() {
return $this->has_default_value;
}
/**
* Has an original value?
* @return boolean
*/
public function hasOriginalValue() {
return $this->query->hasOriginalValue($this);
}
/**
* Adds an alias.
* @param string $alias
*/
public function registerAlias($alias) {
$alias = trim($alias);
if (strlen($alias) > 0 && array_search($alias, $this->aliases) === FALSE) {
array_push($this->aliases, $alias);
}
}
/**
* Checks if it has an alias.
* @param string $alias
* @return boolean
*/
public function isAlias($alias) {
return array_search($alias, $this->aliases) !== FALSE;
}
/**
* String representation of the column.
* @return string
*/
public function __toString() {
return $this->getFullName();
}
}
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