PHP PDO Class and Smarty - php

Question

Hello so currently I am using a php pdo class for my database connection and here is the code
class db extends PDO {
private $error;
private $sql;
private $bind;
private $errorCallbackFunction;
private $errorMsgFormat;
public function __construct($dsn='', $user='', $passwd='') {
$options = array(
PDO::ATTR_PERSISTENT => true,
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
);
if (empty($dsn)) {
$dsn = 'mysql:host=localhost;dbname=db_disaster';
}
if (empty($user)) {
$user = 'root';
}
try {
parent::__construct($dsn, $user, $passwd, $options);
} catch (PDOException $e) {
$this->error = $e->getMessage();
}
}
private function debug() {
if(!empty($this->errorCallbackFunction)) {
$error = array("Error" => $this->error);
if(!empty($this->sql))
$error["SQL Statement"] = $this->sql;
if(!empty($this->bind))
$error["Bind Parameters"] = trim(print_r($this->bind, true));
$backtrace = debug_backtrace();
if(!empty($backtrace)) {
foreach($backtrace as $info) {
if($info["file"] != __FILE__)
$error["Backtrace"] = $info["file"] . " at line " . $info["line"];
}
}
$msg = "";
if($this->errorMsgFormat == "html") {
if(!empty($error["Bind Parameters"]))
$error["Bind Parameters"] = "<pre>" . $error["Bind Parameters"] . "</pre>";
$css = trim(file_get_contents(dirname(__FILE__) . "/error.css"));
$msg .= '<style type="text/css">' . "\n" . $css . "\n</style>";
$msg .= "\n" . '<div class="db-error">' . "\n\t<h3>SQL Error</h3>";
foreach($error as $key => $val)
$msg .= "\n\t<label>" . $key . ":</label>" . $val;
$msg .= "\n\t</div>\n</div>";
}
elseif($this->errorMsgFormat == "text") {
$msg .= "SQL Error\n" . str_repeat("-", 50);
foreach($error as $key => $val)
$msg .= "\n\n$key:\n$val";
}
$func = $this->errorCallbackFunction;
$func($msg);
}
}
public function delete($table, $where, $bind="") {
$sql = "DELETE FROM " . $table . " WHERE " . $where . ";";
$this->run($sql, $bind);
}
private function filter($table, $info) {
$driver = $this->getAttribute(PDO::ATTR_DRIVER_NAME);
if($driver == 'sqlite') {
$sql = "PRAGMA table_info('" . $table . "');";
$key = "name";
}
elseif($driver == 'mysql') {
$sql = "DESCRIBE " . $table . ";";
$key = "Field";
}
else {
$sql = "SELECT column_name FROM information_schema.columns WHERE table_name = '" . $table . "';";
$key = "column_name";
}
if(false !== ($list = $this->run($sql))) {
$fields = array();
foreach($list as $record)
$fields[] = $record[$key];
return array_values(array_intersect($fields, array_keys($info)));
}
return array();
}
private function cleanup($bind) {
if(!is_array($bind)) {
if(!empty($bind))
$bind = array($bind);
else
$bind = array();
}
return $bind;
}
public function insert($table, $info) {
$fields = $this->filter($table, $info);
$sql = "INSERT INTO " . $table . " (" . implode($fields, ", ") . ") VALUES (:" . implode($fields, ", :") . ");";
$bind = array();
foreach($fields as $field)
$bind[":$field"] = $info[$field];
return $this->run($sql, $bind);
}
public function run($sql, $bind="") {
$this->sql = trim($sql);
$this->bind = $this->cleanup($bind);
$this->error = "";
try {
$pdostmt = $this->prepare($this->sql);
if($pdostmt->execute($this->bind) !== false) {
if(preg_match("/^(" . implode("|", array("select", "describe", "pragma")) . ") /i", $this->sql))
return $pdostmt->fetchAll(PDO::FETCH_ASSOC);
elseif(preg_match("/^(" . implode("|", array("delete", "insert", "update")) . ") /i", $this->sql))
return $pdostmt->rowCount();
}
} catch (PDOException $e) {
$this->error = $e->getMessage();
$this->debug();
return false;
}
}
public function select($table, $where="", $bind="", $fields="*") {
$sql = "SELECT " . $fields . " FROM " . $table;
if(!empty($where))
$sql .= " WHERE " . $where;
$sql .= ";";
return $this->run($sql, $bind);
}
public function setErrorCallbackFunction($errorCallbackFunction, $errorMsgFormat="html") {
//Variable functions for won't work with language constructs such as echo and print, so these are replaced with print_r.
if(in_array(strtolower($errorCallbackFunction), array("echo", "print")))
$errorCallbackFunction = "print_r";
if(function_exists($errorCallbackFunction)) {
$this->errorCallbackFunction = $errorCallbackFunction;
if(!in_array(strtolower($errorMsgFormat), array("html", "text")))
$errorMsgFormat = "html";
$this->errorMsgFormat = $errorMsgFormat;
}
}
public function update($table, $info, $where, $bind="") {
$fields = $this->filter($table, $info);
$fieldSize = sizeof($fields);
$sql = "UPDATE " . $table . " SET ";
for($f = 0; $f < $fieldSize; ++$f) {
if($f > 0)
$sql .= ", ";
$sql .= $fields[$f] . " = :update_" . $fields[$f];
}
$sql .= " WHERE " . $where . ";";
$bind = $this->cleanup($bind);
foreach($fields as $field)
$bind[":update_$field"] = $info[$field];
return $this->run($sql, $bind);
}
}
And I am also using Smarty template engine for me to separate my presentation with the application code. So I am now doing a CRUD, and in my edit.php this what it looks like
require_once('header.php');
include('class.db.php');
$db = new db();
$id = $_GET['id'];
$bind = array(
":id" => $id
);
$results = $db->select("Contacts", "ContactID = :id", $bind);
$app->assign('contact', $results);
$app->display('edit.tpl');
My problem is I am still using foreach to output data/s in the textbox in my edit.tpl
{include file="header.tpl" title="Edit Contact"}
{foreach $contact as $r}
<form action="edit.php" method="POST">
Name: <input type="text" name="txt_name" value="{$r.ContactName}"> <br />
Contact: <input type="text" name="txt_contact" value="{$r.ContactNumber}"> <br />
<input type="submit" name="edit_btn" value="Edit Contact">
</form>
{/foreach}
{include file="footer.tpl"}
Is there a better way of doing this? I just want to use foreach in displaying all data, not by just one data from my id

Answer 1

The thing is your db class 'select' method always makes use of PDO fetchAll, if your action is based on a single row only then why not pass just the one result to the template?
$results = $db->select("Contacts", "ContactID = :id", $bind);
if (empty($results)) {
throw new Exception("No contact found");
}
$app->assign('contact', $results[0]); // only pass the one result to the template
$app->display('edit.tpl');
And in the template file, you can simply remove the foreach and since the result is guaranteed to be there already, no need for any checking:
{include file="header.tpl" title="Edit Contact"}
<form action="edit.php" method="POST">
Name: <input type="text" name="txt_name" value="{$contact.ContactName}"> <br />
Contact: <input type="text" name="txt_contact" value="{$contact.ContactNumber}"> <br />
<input type="submit" name="edit_btn" value="Edit Contact">
</form>
{include file="footer.tpl"}