96 lines
3.0 KiB
PHP
96 lines
3.0 KiB
PHP
<?php
|
|
|
|
// Utilities for flatfile functions
|
|
|
|
/** Constant to indicating a column holding floating point numbers */
|
|
define('FLOAT_COL', 'float');
|
|
/** Constant to indicating a column holding integers */
|
|
define('INT_COL', 'int');
|
|
/** Constant to indicating a column holding strings */
|
|
define('STRING_COL', 'string');
|
|
/** Constant to indicating a column holding unix timestamps */
|
|
define('DATE_COL', 'date');
|
|
|
|
|
|
/** EXPERIMENTAL: Encapsulates info about a column in a flatfile DB */
|
|
class Column {
|
|
/**
|
|
* Create a new column object
|
|
*/
|
|
function Column($index, $type) {
|
|
$this->index = $index;
|
|
$this->type = $type;
|
|
}
|
|
}
|
|
|
|
/** EXPERIMENTAL: Represent a column that is a foreign key. Used for temporarily building tables array */
|
|
class JoinColumn {
|
|
function JoinColumn($index, $tablename, $columnname) {
|
|
$this->index = $index;
|
|
$this->tablename = $tablename;
|
|
$this->columnname = $columnname;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* EXPERIMENTAL: Utilities for handling definitions of tables.
|
|
*/
|
|
class TableUtils {
|
|
/**
|
|
* Finds JoinColumns in an array of tables, and adds 'type' fields by looking up the columns
|
|
*
|
|
* @param tables This should be an associative array containing 'tablename' => tabledefinition
|
|
* tabledefinition is itself an associativive array of 'COLUMN_NAME_CONSTANT' => columndefintion
|
|
* COLUMN_NAME_CONSTANT should be a unique constant within the table, and
|
|
* column definition should be a Column object or JoinColumn object
|
|
*/
|
|
function resolveJoins(&$tables) {
|
|
foreach ($tables as $tablename => $discard) {
|
|
// PHP4 compatible: can't do : foreach ($tables as $tablename => &$tabledef)
|
|
// and strangely, if we do
|
|
// foreach ($tables as $tablename => &$tabledef)
|
|
// $tabledef =& $tables[$tablename];
|
|
// then we get bugs
|
|
$tabledef =& $tables[$tablename];
|
|
foreach ($tabledef as $colname => $discard) {
|
|
$coldef =& $tabledef[$colname]; // PHP4 compatible
|
|
if (is_a($coldef, 'JoinColumn') or is_subclass_of($coldef, 'JoinColumn')) {
|
|
TableUtils::resolveColumnJoin($coldef, $tables);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/** @access private */
|
|
function resolveColumnJoin(&$columndef, &$tables) {
|
|
// Doesn't work if the column it is joined to is also
|
|
// a JoinColumn, but I can't think of ever wanting to do that
|
|
$columndef->type = $tables[$columndef->tablename][$columndef->columnname]->type;
|
|
}
|
|
|
|
/** Uses 'define' to create global constants for all the column names */
|
|
function createDefines(&$tables) {
|
|
foreach ($tables as $tablename => $discard) {
|
|
$tabledef = & $tables[$tablename]; // PHP4 compatible
|
|
foreach ($tabledef as $colname => $discard) {
|
|
$coldef = & $tabledef[$colname];
|
|
define(strtoupper($tablename) . '_' . $colname, $coldef->index);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Creates a 'row schema' for a given table definition.
|
|
*
|
|
* A row schema is just an array of the column types for a table,
|
|
* using the constants defined above.
|
|
*/
|
|
function createRowSchema(&$tabledef) {
|
|
$row_schema = array();
|
|
foreach ($tabledef as $colname => $coldef) {
|
|
$row_schema[$coldef->index] = $coldef->type;
|
|
}
|
|
return $row_schema;
|
|
}
|
|
}
|