<!-- Collection of code snippets by Arne Vajhøj -->
<!-- from articles on eksperten.dk / vajhoej.dk (2004-now) -->
<?php
class T1 {
    public $f1;
    public $f2;
    public function __construct($f1, $f2) {
        $this->f1 = $f1;
        $this->f2 = $f2;
    }
}

interface T1DatabaseAccess {
    public function get_one($f2);
    public function get_all();
    public function put($o);
    public function remove($f1);
}

class T1DatabaseAccessPgsql implements T1DatabaseAccess {
    private $server;
    private $username;
    private $password;
    private $database;
    public function __construct($server, $username, $password, $database) {
        $this->server = $server;
        $this->username = $username;
        $this->password = $password;
        $this->database = $database;
    }
    private function get_connection() {
        // connect to server and select database
        $con = pg_connect(sprintf('host=%s port=5432 dbname=%s user=%s password=%s', $this->server, $this->database, $this->username, $this->password)) or die(pg_last_error());
        // return connection (note: no globals)
        return $con;
    }
    public function get_one($f2) {
        // connect to server and select database
        $con = $this->get_connection();
        // prepare SQL statement
        pg_prepare($con, 'stmt_get_one', 'SELECT f1,f2 FROM t1 WHERE f2=$1') or die(pg_last_error($con));
        // execute
        $rs = pg_execute($con, 'stmt_get_one', array($f2)) or die(pg_last_error($con));
        // get first row and field F1
        if($row = pg_fetch_array($rs, NULL, PGSQL_ASSOC)) {
            $res = new T1($row['f1'], $row['f2']);  
        } else {
            die("$f2 not found");
        }
        // close
        pg_query('DEALLOCATE stmt_get_one');
        pg_close($con);
        // return value
        return $res;
    }
    public function get_all() {
        // connect to server and select database
        $con = $this->get_connection();
        // prepare SQL statement
        pg_prepare($con, 'stmt_get_all', 'SELECT f1,f2 FROM t1') or die(pg_last_error($con));
        // execute
        $rs = pg_execute($con, 'stmt_get_all', array()) or die(pg_last_error($con));
        // create array to contain rows
        $res = array();
        // get all rows
        while($row = pg_fetch_array($rs, NULL, PGSQL_ASSOC)) {
            $res[] = new T1($row['f1'], $row['f2']); 
        }
        // close
        pg_query('DEALLOCATE stmt_get_all');
        pg_close($con);
        // return array with rows
        return $res;
    }
    public function put($o) {
        // connect to server and select database
        $con = $this->get_connection();
        // prepare SQL statement
        pg_prepare($con, 'stmt_put', 'INSERT INTO t1(f1,f2) VALUES($1,$2)') or die(pg_last_error($con));
        // execute
        pg_execute($con, 'stmt_put', array($o->f1, $o->f2)) or die(pg_last_error($con));
        // close
        pg_query('DEALLOCATE stmt_put');
        pg_close($con);
    }
    public function remove($f1) {
        // connect to server and select database
        $con = $this->get_connection();
        // prepare SQL statement
        pg_prepare($con, 'stmt_remove', 'DELETE FROM t1 WHERE f1=$1') or die(pg_last_error($con));
        // execute
        pg_execute($con, 'stmt_remove', array($f1)) or die(pg_last_error($con));
        // close
        pg_query('DEALLOCATE stmt_remove');
        pg_close($con);
    }
}

class T1DatabaseAccessFactory {
    const PGSQL = 'pgsql';
    public static function get_database_access($id, $server, $username, $password, $database) {
        if($id === T1DatabaseAccessFactory::PGSQL) {
            return new T1DatabaseAccessPgsql($server, $username, $password, $database);
        } else {
            throw new Exception("Unknown T1DatabaseAccess id: $id");
        }
    }
}

interface T1Presenter {
    public function display($data);
}

class T1PresenterHtmlTable implements T1Presenter {
    public function display($data) {
        $rows = "";
        foreach($data as $row) {
            $f1 = $row->f1;
            $f2 = $row->f2;
            $rows .= sprintf("<tr>\r\n<td>$f1</td>\r\n<td>$f2</td>\r\n</tr>\r\n");
        }
        return "<table>\r\n<tr>\r\n<th>F1</th>\r\n<th>F2</th>\r\n</tr>\r\n$rows</table>\r\n";
    }
}

class T1PresenterFactory {
    const HTML_TABLE = 'HTML Table';
    public static function get_presenter($id) {
        if($id === T1PresenterFactory::HTML_TABLE) {
            return new T1PresenterHtmlTable()   ;
        } else {
            throw new Exception("Unknown T1Presenter id: $id");
        }
    }
}

function test() {
    $data_access = T1DatabaseAccessFactory::get_database_access(T1DatabaseAccessFactory::PGSQL, 'localhost', 'postgres', 'xxxxxx', 'Test');
    $presenter = T1PresenterFactory::get_presenter(T1PresenterFactory::HTML_TABLE);
    $f1 = $data_access->get_one('BB')->f1;
    echo "$f1<br>\r\n";
    $data = $data_access->get_all();
    echo $presenter->display($data);
    $data_access->put(new T1(999, 'XXX'));
    $data = $data_access->get_all();
    echo $presenter->display($data);
    $data_access->remove(999);
    $data = $data_access->get_all();
    echo $presenter->display($data);
}

test();
?>