Uploading And Deleting Photos - php

Question

I have an app that I can upload and delete photos from. Right now I am either able to upload a photo, or I'm able to delete it. But I can't do both for some reason and here's what I mean:
In the code below, in the Photograph class, the variable $db_fields is an array of the columns in the photograph database. If I leave the id field out of the $db_fields array, I am able to upload a photo. But I cannot delete a photo. If I include the id field, I am able to then delete a photo, but now I can't upload one.
What do I need to do here? And if you need to see anything else please let me know.
Thanks,
CM
photograph.php
<?php
require_once(LIB_PATH . DS . 'database.php');
class Photograph extends DatabaseObject {
protected static $table_name = "photographs";
protected static $db_fields = array('id','filename', 'type', 'size', 'caption');
public $id;
public $filename;
public $type;
public $size;
public $caption;
private $temp_path;
protected $upload_dir = "images";
public $errors = array();
protected $upload_errors = array(
UPLOAD_ERR_OK => "No errors.",
UPLOAD_ERR_INI_SIZE => "Larger than upload_max_filesize.",
UPLOAD_ERR_FORM_SIZE => "Larger than form MAX_FILE_SIZE.",
UPLOAD_ERR_PARTIAL => "Partial upload.",
UPLOAD_ERR_NO_FILE => "No file.",
UPLOAD_ERR_NO_TMP_DIR => "No temporary directory.",
UPLOAD_ERR_CANT_WRITE => "Can't write to disk.",
UPLOAD_ERR_EXTENSION => "File upload stopped by extension."
);
public function attach_file($file) {
if (!$file || empty($file) || !is_array($file)) {
$this->errors[] = "No file was uploaded.";
return false;
} elseif ($file['error'] != 0) {
$this->errors[] = $this->upload_errors[$file['error']];
return false;
} else {
$this->temp_path = $file['tmp_name'];
$this->filename = basename($file['name']);
$this->type = $file['type'];
$this->size = $file['size'];
return true;
}
}
public function save() {
if (isset($this->id)) {
$this->update();
} else {
if (!empty($this->errors)) {
return false;
}
if (strlen($this->caption) > 255) {
$this->errors[] = "The caption can only be 255 characters long.";
return false;
}
if (empty($this->filename) || empty($this->temp_path)) {
$this->errors[] = "The file location was not available.";
return false;
}
$target_path = SITE_ROOT . DS . 'public' . DS . $this->upload_dir . DS . $this->filename;
if (file_exists($target_path)) {
$this->errors[] = "The file {$this->filename} already exists.";
return false;
}
if (move_uploaded_file($this->temp_path, $target_path)) {
if ($this->create()) {
unset($this->temp_path);
return true;
}
} else {
$this->errors[] = "The file upload failed, possibly due to incorrect permissions on the upload folder.";
return false;
}
}
}
public function destroy() {
if ($this->delete()) {
$target_path = SITE_ROOT . DS . 'public' . DS . $this->image_path();
return unlink($target_path) ? true : false;
} else {
return false;
}
}
public function image_path() {
return $this->upload_dir . DS . $this->filename;
}
public function size_as_text() {
if ($this->size < 1024) {
return "{$this->size} bytes";
} elseif ($this->size < 1048576) {
$size_kb = round($this->size / 1024);
return "{$size_kb} KB";
} else {
$size_mb = round($this->size / 1048576, 1);
return "{$size_mb} MB";
}
}
public function comments() {
return Comment::find_comments_on($this->id);
}
public static function count_all() {
global $database;
$sql = "SELECT COUNT(*) FROM ".self::$table_name;
$result_set = $database->query($sql);
$row = $database->fetch_array($result_set);
return array_shift($row);
}
}
?>
database_object.php
require_once(LIB_PATH . DS . 'database.php');
class DatabaseObject {
private static $table_name;
public static function find_all() {
global $database;
$query = "SELECT * FROM ".static::$table_name;
return static::find_by_sql($query);
}
public static function find_by_id($id=0) {
global $database;
$query = "SELECT * FROM " . static::$table_name . " WHERE id =".$database->escape_value($id)." LIMIT 1";
$result_array = static::find_by_sql($query);
return !empty($result_array) ? array_shift($result_array) : false;
}
public static function find_by_sql($sql = "") {
global $database;
$result_set = $database->query($sql);
$object_array = array();
while ($row = $database->fetch_array($result_set)) {
$object_array[] = static::instantiate($row);
}
return $object_array;
}
private static function instantiate($record) {
$object = new static();
foreach ($record as $attribute => $value) {
if ($object->has_attribute($attribute)) {
$object->$attribute = $value;
}
}
return $object;
}
private function has_attribute($attribute) {
$object_vars = $this->attributes();
return array_key_exists($attribute, $object_vars);
}
protected function attributes() {
$attributes = array();
foreach (static::$db_fields as $field) {
if (property_exists($this, $field)) {
$attributes[$field] = $this->$field;
}
}
return $attributes;
}
protected function sanitized_attributes() {
global $database;
$clean_attributes = array();
foreach ($this->attributes() as $key => $value) {
$clean_attributes[$key] = $database->escape_value($value);
}
return $clean_attributes;
}
public function save() {
return isset($this->id) ? $this->update() : $this->create();
}
public function create() {
global $database;
$attributes = $this->attributes();
$sql = "INSERT INTO ".static::$table_name." (";
$sql .= join(", ", array_keys($attributes));
$sql .= ") VALUES ('";
$sql .= join("', '", array_values($attributes));
$sql .= "')";
if($database->query($sql)) {
$this->id = $database->insert_id();
return true;
} else {
return false;
}
}
public function update() {
global $database;
$attributes = $this->sanitized_attributes();
$attribute_pairs = array();
foreach ($attributes as $key => $value) {
$attribute_pairs[] = "{$key}='{$value}'";
}
$sql = "UPDATE " . static::$table_name . " SET ";
$sql .= join(", ", $attribute_pairs);
$sql .= " WHERE id=" . $database->escape_value($this->id);
$database->query($sql);
return ($database->affected_rows() == 1) ? true : false;
}
public function delete() {
global $database;
$sql = "DELETE FROM " . static::$table_name;
$sql .= " WHERE id=" . $database->escape_value($this->id);
$sql .= " LIMIT 1";
$database->query($sql);
return ($database->affected_rows() == 1) ? true : false;
}
}
?>
photo_upload.php
<?php
require_once('../../includes/initialize.php');
if (!$session->is_logged_in()) {
redirect_to("login.php");
}
?>
<?php
$max_file_size = 10485760; // expressed in bytes
// 10240 = 10 KB
// 102400 = 100 KB
// 1048576 = 1 MB
// 10485760 = 10 MB
//2e+6
$message="";
if (isset($_POST['submit'])) {
$photo = new Photograph();
$photo->caption = $_POST['caption'];
$photo->attach_file($_FILES['file_upload']);
if ($photo->save()) {
// Success
$session->message("Photograph uploaded successfully.");
redirect_to('list_photos.php');
} else {
// Failure
$message = join("<br />", $photo->errors);
}
}
?>
<?php include_layout_template('admin_header.php'); ?>
<h2>Photo Upload</h2>
<?php echo output_message($message); ?>
<form action="photo_upload.php" enctype="multipart/form-data" method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="<?php echo $max_file_size; ?>" />
<p><input type="file" name="file_upload" /></p>
<p style="font-color:#000;">Caption: <input type="text" name="caption" value="" /></p>
<input type="submit" name="submit" value="Upload" />
</form>
<?php include_layout_template('admin_footer.php'); ?>
from 'database_object.php'
public function create() {
global $database;
$attributes = $this->attributes();
$sql = "INSERT INTO ".static::$table_name." (";
$sql .= join(", ", array_keys($attributes));
$sql .= ") VALUES ('";
$sql .= join("', '", array_values($attributes));
$sql .= "')";
if($database->query($sql)) {
$this->id = $database->insert_id();
return true;
} else {
return false;
}
}

Answer 1

A summary of the temporary solution, so you can file this question completed.
In the method of create, you would grab all attributes (fields) using $attributes = $this->attributes();, then use the array keys and values to generate the SQL statement.
This would also include the id field.
The problem then occurred from trying to do an INSERT operation and including the id field (which appears to be an auto_increment unique indexed field). This was causing a big problem on create.
A temporary solution, was to drop that field from the $attributes you use to build the query, using unset($attributes['id']); after $attributes = $this->attributes(); would accomplish this, but its not pretty and can be developed better later at your leisure.
I hope I helped, and merry coding ;)